HOME

TheInfoList



OR:

XYY syndrome, also known as Jacobs syndrome, is an aneuploid genetic condition in which a male has an extra
Y chromosome The Y chromosome is one of two sex chromosomes in therian mammals and other organisms. Along with the X chromosome, it is part of the XY sex-determination system, in which the Y is the sex-determining chromosome because the presence of the ...
. There are usually few symptoms. These may include being taller than average and an increased risk of
learning disabilities Learning disability, learning disorder, or learning difficulty (British English) is a condition in the brain that causes difficulties comprehending or processing information and can be caused by several different factors. Given the "difficulty ...
. The person is generally otherwise normal, including typical rates of
fertility Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...
. The condition is generally not inherited but rather occurs as a result of a random event during sperm development. Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime. There are 47 chromosomes, instead of the usual 46, giving a 47,XYY
karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...
. Treatment may include
speech therapy Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...
or extra help with schoolwork, and outcomes are generally positive. The condition occurs in about 1 in 1,000 male births. Many people with the condition are unaware that they have it. The condition was first described in 1961.


Signs and symptoms


Physical traits

People with the 47,XYY
karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...
have an increased growth rate from early childhood, with an average final height approximately above expected final height. In
Edinburgh Edinburgh is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. The city is located in southeast Scotland and is bounded to the north by the Firth of Forth and to the south by the Pentland Hills. Edinburgh ...
,
Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...
, eight 47,XYY boys born 1967–1972 and identified in a newborn screening programme had an average height of at age 18—their fathers' average height was , their mothers' average height was . The increased gene dosage of three X/Y chromosome pseudoautosomal region (PAR1) SHOX genes has been postulated as a cause of the increased stature seen in all three sex chromosome trisomies: 47,XXX, 47,XXY, and 47,XYY. p. 2304: Table 561-1. Differential diagnosis of tall stature and overgrowth syndromes. Postnatal overgrowth leading to childhood tall stature—includes: Klinefelter syndrome (XXY), SHOX excess syndromes, XYY. * * * Severe
acne Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...
was noted in a very few early case reports, but dermatologists specializing in acne now doubt the existence of a relationship with 47,XYY. Prenatal
testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
levels are normal in 47,XYY males. Most 47,XYY males have normal sexual development and have normal fertility.


Cognitive and behavioral traits

In contrast to the other common sex chromosome aneuploidies47,XXX and 47,XXY ( Klinefelter syndrome)—the average of the IQ scores of 47,XYY boys identified by newborn screening programs was not reduced compared to the general population. In a summary of six prospective studies of 47,XYY boys identified by newborn screening programmes, twenty-eight 47,XYY boys had an average 100.76
verbal IQ The Wechsler Adult Intelligence Scale (WAIS) is an Intelligence quotient, IQ test designed to measure intelligence and cognitive ability in adults and older adolescents. For children between the ages of 6 and 16, Wechsler Intelligence Scale for C ...
, 108.79 performance IQ, and 105.00 full-scale IQ. In a
systematic review A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on ...
including two prospective studies of 47,XYY boys identified by newborn screening programs and one retrospective study of 47,XYY men identified by screening men over in height, forty-two 47,XYY boys and men had an average 99.5 verbal IQ and 106.4 performance IQ. In prospective studies of 47,XYY boys identified by newborn screening programs, the IQ scores of 47,XYY boys were usually slightly lower than those of their siblings. In Edinburgh, fifteen 47,XYY boys with siblings identified in a newborn screening program had an average 104.0 verbal IQ and 106.7 performance IQ, while their siblings had an average 112.9 verbal IQ and 114.6 performance IQ. Approximately half of 47,XYY boys identified by newborn screening programs had learning difficulties—a higher proportion than found among siblings and above-average-IQ control groups. In Edinburgh, 54% of 47,XYY boys (7 of 13) identified in a newborn screening program received remedial reading teaching compared to 18% (4 of 22) in an above-average-IQ control group of 46,XY boys matched by their father's social class. In
Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...
, USA 55% of 47,XYY boys (6 of 11) identified in a newborn screening program had learning difficulties and received part-time resource room help compared to 11% (1 of 9) in an above-average-IQ control group of 46,XY boys with familial balanced autosomal chromosome translocations. Developmental delays and behavioral problems are also found, but these characteristics vary widely among affected boys and men, are not unique to 47,XYY and are managed no differently from in 46,XY males. Aggression is not seen more frequently in 47,XYY males. Patients with XYY syndrome have been shown to have a higher risk of developing certain diseases such as
asthma Asthma is a common long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wh ...
, seizure problems, and tremors. Some 47,XYY patients have been found to have genitourinary malformations. These include cryptorchidism, hypoplastic scrotum, microphallus, and hypospadias. These men could be diagnosed with infertility as a result of oligospermia or sperm chromosomal abnormalities. According to certain psychological studies, people with XYY syndrome may have problems with impulse control and emotional regulation. Increased testosterone levels were found to be correlated with an increased risk of aggressive behavior in incarcerated males with 47,XYY syndrome. 47,XYY is not inherited; it usually occurs as a random event during the formation of
sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...
cells. An incident in chromosome separation during anaphase II (of meiosis II) called
nondisjunction Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division (mitosis/meiosis). There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I ...
can result in sperm cells with an extra copy of the Y-chromosome. If one of these atypical sperm cells contributes to the genetic makeup of a child, the child will have an extra Y-chromosome in each of the body's cells. In some cases, the extra Y-chromosome results from nondisjunction during
mitosis Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ...
in early embryonic development. This can produce 46,XY/47,XYY
mosaics A mosaic () is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/Mortar (masonry), mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and ...
.


Diagnosis

47,XYY syndrome is not usually diagnosed until learning issues are present. The syndrome is diagnosed in an increasing number of children prenatally by amniocentesis and chorionic villus sampling in order to obtain a chromosome karyotype, where the abnormality can be observed. It is estimated that only 15–20% of children with 47,XYY syndrome are ever diagnosed. Of these, approximately 30% are diagnosed prenatally. For the rest of those diagnosed after birth, around half are diagnosed during childhood or adolescence after developmental delays are observed. The rest are diagnosed after any of a variety of symptoms, including fertility problems (5%) have been seen.


Epidemiology

Around 1 in 1,000 boys are born with a 47,XYY karyotype. The incidence of 47,XYY is not known to be affected by the parents' ages.


History


1960s

In April 1956, '' Hereditas'' published the discovery by cytogeneticists Joe Hin Tjio and Albert Levan at
Lund University Lund University () is a Public university, public research university in Sweden and one of Northern Europe's oldest universities. The university is located in the city of Lund in the Swedish province of Scania. The university was officially foun ...
in
Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...
that the normal number of chromosomes in
diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...
human cells was 46—not 48, as had been believed for the preceding thirty years. In the wake of the establishment of the normal number of human chromosomes, 47,XYY was the last of the common sex chromosome aneuploidies to be discovered, two years after the discoveries of 47,XXY,
45,X Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) lead ...
and 47,XXX in 1959. Even the much less common 48,XXYY had been discovered in 1960, a year before 47,XYY. Screening for those X chromosome aneuploidies was possible before the advent of human chromosome analysis by noting the presence or absence of "female" sex chromatin bodies ( Barr bodies) in the nuclei of
interphase Interphase is the active portion of the cell cycle that includes the G1, S, and G2 phases, where the cell grows, replicates its DNA, and prepares for mitosis, respectively. Interphase was formerly called the "resting phase," but the cell i ...
cells in buccal smears, a technique developed a decade ''before'' the first reported sex chromosome aneuploidy. An analogous technique to screen for Y-chromosome aneuploidies by noting supernumerary "male" sex chromatin bodies was not developed until 1970, a decade ''after'' the first reported male sex chromosome aneuploidy. * The first published report of a man with a 47,XYY karyotype was by the American cytogeneticist Avery Sandberg and his colleagues at Roswell Park Comprehensive Cancer Center (then known as Roswell Park Memorial Institute) in
Buffalo, New York Buffalo is a Administrative divisions of New York (state), city in the U.S. state of New York (state), New York and county seat of Erie County, New York, Erie County. It lies in Western New York at the eastern end of Lake Erie, at the head of ...
in 1961. It was an incidental finding in a normal 44-year-old, 6 ft. 83 cmtall man of average intelligence who was karyotyped because he had a daughter with Down syndrome. * Only a dozen isolated 47,XYY cases were reported in the medical literature in the four years following the first report by Sandberg. The XYY syndrome, if named after the discoverer, should rightly be termed Sandberg syndrome and not Jacobs syndrome although the British cytogeneticist Patricia Jacobs did indeed contribute meaningfully to medical knowledge of XYY. In December 1965 and March 1966, ''
Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
'' and ''
The Lancet ''The Lancet'' is a weekly peer-reviewed general medical journal, founded in England in 1823. It is one of the world's highest-impact academic journals and also one of the oldest medical journals still in publication. The journal publishes ...
'' published the first preliminary reports by Jacobs and her colleagues at the MRC Human Genetics Unit at Western General Hospital in
Edinburgh Edinburgh is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. The city is located in southeast Scotland and is bounded to the north by the Firth of Forth and to the south by the Pentland Hills. Edinburgh ...
of a chromosome survey of 315 male patients at
State Hospital The State Hospital (also known as Carstairs Hospital, or simply Carstairs) is a psychiatric hospital located close to the villages of Carstairs and Carstairs Junction, in South Lanarkshire, Scotland. It provides care and treatment in conditions ...
in
Carstairs Carstairs (, Scottish Gaelic: ''Caisteal Tarrais'') is a village in South Lanarkshire, Scotland. Carstairs is located east of the county town of Lanark and the West Coast Main Line runs through the village. The village is served by Carstairs r ...
,
Lanarkshire Lanarkshire, also called the County of Lanark (; ), is a Counties of Scotland, historic county, Lieutenancy areas of Scotland, lieutenancy area and registration county in the Central Lowlands and Southern Uplands of Scotland. The county is no l ...
Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...
's only special security hospital for developmentally disabled people —that found nine patients, ages 17 to 36, averaging almost 6 ft. in height (avg. 5'11", range: 5'7" to 6'2"), had a 47,XYY karyotype, and mischaracterized them as aggressive and violent criminals. Over the next decade, almost all published XYY studies were on height-selected, institutionalized XYY males. In January 1968 and March 1968, ''
The Lancet ''The Lancet'' is a weekly peer-reviewed general medical journal, founded in England in 1823. It is one of the world's highest-impact academic journals and also one of the oldest medical journals still in publication. The journal publishes ...
'' and ''
Science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...
'' published the first U.S. reports of tall, institutionalized XYY males by Mary Telfer, a
biochemist Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and Cell (biology), cell parts. The word "biochemist" is a portmanteau of ...
, and colleagues at the Elwyn Institute. * Telfer found five tall, developmentally disabled XYY boys and men in hospitals and penal institutions in
Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
, and since four of the five had at least moderate facial
acne Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...
, reached the erroneous conclusion that acne was a defining characteristic of XYY males. After learning that convicted mass murderer Richard Speck had been karyotyped, Telfer not only incorrectly assumed the acne-scarred Speck was XYY, but reached the false conclusion that Speck was the archetypical XYY male—or "supermale" as Telfer referred to XYY males outside of peer-reviewed scientific journals. In April 1968, ''
The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...
''—using Telfer as a main source—introduced the XYY genetic condition to the general public in a three-part series on consecutive days that began with a Sunday front-page story about the planned use of the condition as a mitigating factor in two murder trials in
Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
Daniel Hugon, Paris, France * * and
Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...
Lawrence Hannell, Melbourne, Australia * * * An Australian murder case that was reported to have been decided on the basis of the so-called XYY syndrome actually was not concerned with chromosome counts at all.—and falsely reported that Richard Speck was an XYY male and that the condition would be used in an appeal of his murder conviction. * * * * * * —article by
Vanderbilt University Vanderbilt University (informally Vandy or VU) is a private university, private research university in Nashville, Tennessee, United States. Founded in 1873, it was named in honor of shipping and railroad magnate Cornelius Vanderbilt, who provide ...
endocrinologist and geneticist Eric Engel, who performed two confidential chromosome analyses of Speck in September 1966 and June 1968. Based on mischaracterizations of XYY males as aggressive and violent criminals in the December 1965 and March 1966 preliminary reports by Jacobs, et al., Engel had made an unsolicited request in August 1966 to Speck's appointed defense attorney, Cook County Public Defender Gerald W. Getty, to confidentially karyotype Speck—which was repeated after false news reports in April 1968 that Speck was XYY.
The series was echoed the following week by articles—again using Telfer as a main source—in ''
Time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
'' and ''
Newsweek ''Newsweek'' is an American weekly news magazine based in New York City. Founded as a weekly print magazine in 1933, it was widely distributed during the 20th century and has had many notable editors-in-chief. It is currently co-owned by Dev P ...
'', and six months later in ''
The New York Times Magazine ''The New York Times Magazine'' is an American Sunday magazine included with the Sunday edition of ''The New York Times''. It features articles longer than those typically in the newspaper and has attracted many notable contributors. The magazi ...
''. In December 1968, the '' Journal of Medical Genetics'' published the first XYY review article—by Willam Michael Court Brown (1918–1969), director of the MRC Human Genetics Unit—which reported that he had found no overrepresentation of XYY males in nationwide chromosome surveys of prisons and hospitals for developmentally disabled and mentally ill people in Scotland, and concluded that studies confined to institutionalized XYY males may be guilty of
selection bias Selection bias is the bias introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population inte ...
, and that long-term longitudinal prospective studies of newborn XYY boys were needed. In May 1969, at the annual meeting of the
American Psychiatric Association The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 39,200 members who are in ...
, Telfer and her Elwyn Institute colleagues reported that case studies of the institutionalized XYY and XXY males they had found convinced them that XYY males had been falsely stigmatized and that their behavior may not be significantly different from chromosomally normal 46,XY males. In June 1969, the
National Institute of Mental Health The National Institute of Mental Health (NIMH) is one of 27 institutes and centers that make up the National Institutes of Health (NIH). The NIH, in turn, is an agency of the United States Department of Health and Human Services and is the primar ...
(NIMH) Center for Studies of Crime and Delinquency held a two-day XYY conference in Chevy Chase, Maryland. In December 1969, with a grant from the NIMH Center for Studies of Crime and Delinquency, cytogeneticist Digamber Borgaonkar at Johns Hopkins Hospital began a chromosome survey of (predominantly African-American) boys ages 8 to 18 in all
Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
institutions for delinquent, neglected, or mentally ill juveniles, which was suspended from February–May 1970 due to an
American Civil Liberties Union The American Civil Liberties Union (ACLU) is an American nonprofit civil rights organization founded in 1920. ACLU affiliates are active in all 50 states, Washington, D.C., and Puerto Rico. The budget of the ACLU in 2024 was $383 million. T ...
(ACLU) lawsuit regarding the study's lack of
informed consent Informed consent is an applied ethics principle that a person must have sufficient information and understanding before making decisions about accepting risk. Pertinent information may include risks and benefits of treatments, alternative treatme ...
. In the late 1960s and early 1970s, screening of consecutive newborns for sex chromosome abnormalities was undertaken at seven centers worldwide: in
Denver Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...
(Jan 1964–1974),
Edinburgh Edinburgh is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. The city is located in southeast Scotland and is bounded to the north by the Firth of Forth and to the south by the Pentland Hills. Edinburgh ...
(Apr 1967–Jun 1979),
New Haven New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 U.S. census, New Haven is the third largest city in Co ...
(Oct 1967–Sep 1968),
Toronto Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...
(Oct 1967–Sep 1971),
Aarhus Aarhus (, , ; officially spelled Århus from 1948 until 1 January 2011) is the second-largest city in Denmark and the seat of Aarhus municipality, Aarhus Municipality. It is located on the eastern shore of Jutland in the Kattegat sea and app ...
(Oct 1969–Jan 1974, Oct 1980–Jan 1989),
Winnipeg Winnipeg () is the capital and largest city of the Provinces and territories of Canada, Canadian province of Manitoba. It is centred on the confluence of the Red River of the North, Red and Assiniboine River, Assiniboine rivers. , Winnipeg h ...
(Feb 1970–Sep 1973), and
Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...
(Apr 1970–Nov 1974). * * * The Boston study, led by
Harvard Medical School Harvard Medical School (HMS) is the medical school of Harvard University and is located in the Longwood Medical and Academic Area, Longwood Medical Area in Boston, Massachusetts. Founded in 1782, HMS is the third oldest medical school in the Un ...
child psychiatrist Stanley Walzer at
Children's Hospital A children's hospital (CH) is a hospital that offers its services exclusively to infants, children, adolescents, and young adults from birth up to until age 18, and through age 21 and older in the United States. In certain special cases, the ...
, was unique among the seven newborn screening studies in that it only screened newborn ''boys'' (non-private-ward newborn boys at the Boston Hospital for Women) and was funded in part by grants from the NIMH Center for Studies of Crime and Delinquency. * * * * * * * * * * * * * The Edinburgh study was led by Shirley Ratcliffe who focused her career on it and published the results in 1999.


1970s

In December 1969, Lore Zech at the
Karolinska Institute The Karolinska Institute (KI; ; sometimes known as the (Royal) Caroline Institute in English) is a research-led medical university in Solna within the Stockholm urban area of Sweden and one of the foremost medical research institutes globally ...
in Stockholm first reported intense
fluorescence Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colore ...
of the A T-rich distal half of the long arm of the Y chromosome in the nuclei of metaphase cells treated with quinacrine mustard. In April 1970, Peter Pearson and Martin Bobrow at the MRC Population Genetics Unit in
Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ...
and Canino Vosa at the
University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...
reported fluorescent "male" sex chromatin bodies in the nuclei of interphase cells in buccal smears treated with quinacrine dihydrochloride, which could be used to screen for Y chromosome aneuploidies like 47,XYY. * In December 1970, at the annual meeting of the
American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...
(AAAS), its retiring president, geneticist H. Bentley Glass, cheered by the legalization of abortion in New York, envisioned a future where pregnant women would be required by the government to abort XYY "sex deviants". Mischaracterization of the XYY genetic condition was quickly incorporated into high school biology textbooks and medical school psychiatry textbooks, * where misinformation still persists decades later. In 1973, child psychiatrist Herbert Schreier at Children's Hospital told Harvard Medical School microbiologist Jon Beckwith of Science for the People that he thought Walzer's Boston XYY study was unethical; Science for the People investigated the study and, regarding the study, filed an ethics complaint with Harvard Medical School in March 1974. In November 1974, Science for the People went public with their objections to the Boston XYY study in a press conference and a ''
New Scientist ''New Scientist'' is a popular science magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organ ...
'' article alleging inadequate informed consent, a lack of benefit (since no specific treatment was available) but substantial risk (by stigmatization with a false stereotype) to the subjects, and that the unblinded experimental design could not produce meaningful results regarding the subjects' behavior. In December 1974, the Harvard Standing Committee on Medical Research issued a report supporting the Boston XYY study, and in March 1975, the faculty voted 199–35 to allow continuation of the study. After April 1975, screening of newborns was discontinued—changes to informed consent procedures and pressure from additional advocacy groups, including the Children's Defense Fund, having led to the discontinuation of the last active U.S. newborn screening programs for sex chromosome abnormalities in Boston and Denver. In a paper published in ''
New Scientist ''New Scientist'' is a popular science magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organ ...
'' on November 14, 1974 entitled "XYY syndrome: a dangerous myth" found no link was found between having an extra Y chromosome and violent behavior. According to the paper, adolescents found to have an extra Y chromosome in a
Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
institution were chemically sterilized to attempt to maintain "normal behavior," despite this the paper found no major behavioral differences between XY and XYY individuals. In August 1976, ''Science'' published a retrospective cohort study by
Educational Testing Service Educational Testing Service (ETS), founded in 1947, is the world's largest private educational testing and assessment organization. It is headquartered in Lawrence Township, Mercer County, New Jersey, Lawrence Township, New Jersey, but has a P ...
psychologist Herman Witkin and colleagues that screened the tallest 16% of men (over 184 cm (6'0") in height) born in
Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...
from 1944 to 1947 for XXY and XYY karyotypes, and found an increased rate of minor criminal convictions for property crimes among sixteen XXY and twelve XYY men may be related to the lower intelligence of those with criminal convictions, but found no evidence that XXY or XYY men were inclined to be aggressive or violent. * * * *


1980s and later

The March of Dimes sponsored five international conferences in June 1974, November 1977, May 1981, June 1984, and June 1989 and published articles from the conferences in book form in 1979, 1982, 1986, and 1991 from seven longitudinal prospective cohort studies on the development of over 300 children and young adults with sex chromosome abnormalities identified in the screening of almost 200,000 consecutive births in hospitals in Denver, Edinburgh, New Haven, Toronto, Aarhus, Winnipeg, and Boston from 1964 to 1975. These seven studies—the only unbiased studies of unselected individuals with sex chromosome abnormalities—have replaced the older, biased studies of institutionalized individuals in understanding the development of individuals with sex chromosome abnormalities. In May 1997, '' Nature Genetics'' published the discovery by Ercole Rao and colleagues of the X/Y chromosome pseudoautosomal region (PAR1) SHOX gene, haploinsufficiency of which leads to short stature in
Turner syndrome Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) lea ...
(45,X). It was subsequently postulated that the increased gene dosage of three SHOX genes leads to tall stature in the sex chromosome trisomies 47,XXX, 47,XXY, and 47,XYY. In July 1999, '' Psychological Medicine'' published a case-control study by Royal Edinburgh Hospital psychiatrist Michael Götz and colleagues that found an increased rate of criminal convictions among seventeen XYY men identified in the Edinburgh newborn screening study compared to an above-average-IQ control group of sixty XY men, which multiple
logistic regression In statistics, a logistic model (or logit model) is a statistical model that models the logit, log-odds of an event as a linear function (calculus), linear combination of one or more independent variables. In regression analysis, logistic regres ...
analysis indicated was mediated mainly through lowered intelligence. In June 2002, the '' American Journal of Medical Genetics'' published results from a longitudinal prospective cohort Denver Family Development Study led by pediatrician and geneticist Arthur Robinson, which found that in fourteen prenatally diagnosed 47,XYY boys (from high
socioeconomic status Socioeconomic status (SES) is a measurement used by economics, economists and sociology, sociologsts. The measurement combines a person's work experience and their or their family's access to economic resources and social position in relation t ...
families), IQ scores available for six boys ranged from 100 to 147 with a mean of 120. For the eleven of fourteen boys with siblings, in nine instances their siblings were stronger academically, but in one case the subject was performing equal to, and in another case superior to, his siblings.


Society and culture

Some medical geneticists question whether the term "
syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek language, Greek σύνδρομον, meaning "concurrence". When a sy ...
" is appropriate for this condition because many people with this karyotype appear normal.


In popular culture

In June 1970, '' The XYY Man'' was published—the first of seven Kenneth Royce spy novels whose fictional tall, intelligent, nonviolent XYY hero was a reformed expert cat burglar recruited by British intelligence for dangerous assignments—and later adapted into a thirteen-episode British summer television series broadcast in 1976 and 1977. In other fictional television works, a January 1971 episode "By the Pricking of My Thumbs ..." of the British science fiction TV series '' Doomwatch'' featured an XYY boy expelled from school because his genetic condition led him to be falsely accused of nearly blinding another boy. By the Pricking of My Thumbs ... written by Robin Chapman. Sixteen-year-old Stephen Franklin is expelled from school because, his father says, he has an obscure genetic defect—an extra "Y" chromosome. A November 1993 episode of the American police procedural TV series '' Law & Order'', "Born Bad", portrays a 14-year-old XYY sociopathic murderer. One of TV's most consistently rewarding series takes a grim and unforgettable detour into the bleak mindset of a teen-age sociopathic murderer. Is society to blame, or as his lawyer argues, is he genetically predisposed to violence, with an extra "Y" chromosome? … the boy's hopeless future seems all too evident. The May 2007 season finale episode, "Born To Kill", of the American police procedural TV series '' CSI: Miami'' depicts a 34-year-old XYY
serial killer A serial killer (also called a serial murderer) is a person who murders three or more people,An offender can be anyone: * * * * * (This source only requires two people) with the killings taking place over a significant period of time in separat ...
. There's nothing funny about the season finale. That episode is about a serial killer with "criminal" genes. "It's a real-life natural-born killer situation", executive producer Ann Donahue says. "Usually girls have XX chromosomes and boys have XY, but this killer is XYY, which means too much testosterone." Among other niceties, the killer who has ties to Boston… brands his female victims with the letter Y. The false stereotype of XYY boys and men as violent criminals has also been used as a plot device in the
horror film Horror is a film genre that seeks to elicit physical or psychological fear in its viewers. Horror films often explore dark subject matter and may deal with Transgressive art, transgressive topics or themes. Broad elements of the genre include Mo ...
s ''Il gatto a nove code'' in February 1971 (dubbed into English as ''
The Cat o' Nine Tails ''The Cat o' Nine Tails'' () is a 1971 English-language Italian film directed by Dario Argento, adapted from a story by Dardano Sacchetti, Luigi Cozzi, and an uncredited Bryan Edgar Wallace. It stars Karl Malden, James Franciscus, and Catherine S ...
'' in May 1971) and '' Alien 3'' in May 1992. The main character of the 2005 film '' Neo Ned'' is a
neo-nazi Neo-Nazism comprises the post–World War II militant, social, and political movements that seek to revive and reinstate Nazism, Nazi ideology. Neo-Nazis employ their ideology to promote hatred and Supremacism#Racial, racial supremacy (ofte ...
who has an extra Y chromosome.


See also

* Sex chromosome anomalies * Klinefelter syndrome * XXYY syndrome * XYYY syndrome * XYYYY syndrome *
Turner syndrome Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) lea ...
*
Trisomy X Trisomy X, also known as triple X syndrome and characterized by the karyotype 47,XXX, is a chromosome disorder in which a female has an extra copy of the X chromosome. It is relatively common and occurs in 1 in 1,000 females, but is rarely diagn ...


References


External links

* Nielsen, Johannes (1998)
XYY males. An orientation
{{DEFAULTSORT:Xyy Syndrome Sex chromosome aneuploidies Y chromosome Wikipedia medicine articles ready to translate Rare syndromes