Peters-plus syndrome or Krause–Kivlin syndrome is a

hereditary Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...

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 ...

defined by Peters' anomaly,

dwarfism Dwarfism is a condition of people and animals marked by unusually small size or short stature. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dwarfism is . '' ...

and

intellectual disability Intellectual disability (ID), also known as general learning disability (in the United Kingdom), and formerly mental retardation (in the United States), Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010).Archive is a generalized neurodevelopmental ...

Signs and symptoms

Features of this syndrome include Peters' anomaly,

corneal opacity Corneal opacification is a term used when the human cornea loses its transparency. The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. Transparency of the cornea is dependent on the uniform diamete ...

, central defect of

Descemet's membrane Descemet's membrane ( or the Descemet membrane) is the basement membrane that lies between the corneal proper substance, also called stroma, and the endothelial layer of the cornea. It is composed of different kinds of collagen (Type IV and VIII ...

, and shallow anterior chamber with synechiae between the iris and cornea. Craniofacial abnormalities commonly seen in patients with PPS include

hypertelorism Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits (eyes), or orbital hypertelorism. In this condition, the distance between the inner eye corners, a ...

, ear malformations, micrognathia, round face and broad neck, and

cleft lip A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nasal cavi ...

and

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

. Infants are commonly born small for gestational age and have delayed growth. It is associated with short limb

and mild to severe

and

autism spectrum disorder Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing di ...

Cause

The pattern of inheritance of Peters-plus is

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...

, where both parents are heterozygous they can produce a child with the syndrome. The B3GALTL (now called B3GLCT) gene codes for the enzyme beta 3-glucosyltransferase (B3Glc-T). The beta 3-glucosyltransferase enzyme is responsible for

glycosylation Glycosylation is the reaction in which a carbohydrate (or ' glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not ...

, the attachment of sugars to proteins, which through this modification allows for performance of a wider variety of functions. The mutations of the B3GLCT gene in affected individuals results in loss-of-function of the beta 3-glucosyltransferase enzyme. The result of this disruption in glycosylation is a change to the

secondary structure Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta ...

of the mRNA. These mutations of the B3GLCT gene lead to the production of an abnormally short, nonfunctional version of the beta 3-

glucosyltransferase Glucosyltransferases are a type of glycosyltransferase that enable the transfer of glucose. Examples include: * glycogen synthase * glycogen phosphorylase Glycogen phosphorylase is one of the phosphorylase enzymes (). Glycogen phosphorylase c ...

(B3Glc-T) enzyme, which disrupts glycosylation. The phenotypic effects of the B3GLCT mutations result in a triad of well known phenotypes; Peters anomaly (also classified as anterior segment defects, a defect in the anterior cornea), short stature,

brachydactyly Brachydactyly () is a medical term denoting the presence of abnormally short digits (fingers or toes) at birth. The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an inherited, dominant t ...

, in addition to several other less frequently observed phenotypes. A study of 55 patients with Peters-plus-related phenotypes, but lacking the most common combination (Peters anomaly, short stature, and brachydactyly), revealed none of those cases displayed mutation in the B3GLCT gene. Thus PPS-like signs and symptoms, when they occur independently of each other, provide strong evidence that the B3GLCT gene mutation is in fact responsible for actual cases Peters-plus syndrome.

History

Krause–van Schooneveld–Kivlin syndrome is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the

National Institutes of Health The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. It was founded in 1887 and is part of the United States Department of Health and Human Service ...

(NIH). It was characterized in 1984 by van Schooneveld.

References

External links

GeneReviews/NCBI/NIH/UW entry on Peters Plus Syndrome

OMIM entries on Peters Plus syndrome
* {{eMedicine, article, 1200372, Peters Anomaly on

eMedicine eMedicine is an online clinical medical knowledge base founded in 1996 by doctors Scott Plantz and Jonathan Adler, and computer engineers Joanne Berezin and Jeffrey Berezin. The eMedicine website consists of approximately 6,800 medical topic revi ...

Rare syndromes

Signs and symptoms

Cause

History

See also

References

External links