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Trigonocephaly
Trigonocephaly is a congenital condition due to premature Synostosis, fusion of the metopic suture (), leading to a triangular forehead. The premature merging of the two frontal bones leads to transverse growth restriction and parallel growth expansion. It may occur as one component of a syndrome together with other abnormalities, or in isolated form. The term is . Cause Trigonocephaly can either occur in a syndrome or isolated, all by itself. Trigonocephaly is associated with the following syndromes: Bohring-Opitz syndrome, Muenke syndrome, Jacobsen syndrome, Baller–Gerold syndrome and Say–Meyer syndrome. The etiology of trigonocephaly is mostly unknown although there are three main theories. Trigonocephaly is probably a multifactorial congenital condition, but due to limited proof of these theories this cannot safely be concluded. Intrinsic bone malformation The first theory assumes that the origin of pathological synostosis lies within disturbed bone formation early on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Say–Meyer Syndrome
Say–Meyer syndrome is a rare X-linked genetic disorder that is mostly characterized as developmental delay. It is one of the rare causes of short stature. It is closely related with trigonocephaly (a misshapen forehead due to premature fusion of bones in the skull). People with Say–Meyer syndrome have impaired growth, deficits in motor skills development and mental state. It is suggested that it is from a X-linked transmission. Signs and symptoms Common signs of Say–Meyer syndrome are trigonocephaly as well as head and neck symptoms. The head and neck symptoms come in the form of craniosynostosis affecting the metopic suture (the dense connective tissue structure that divides the two halves of the skull in children which usually fuse together by the age of six). Symptoms of Say–Meyer syndrome other than developmental delay and short stature include * Intellectual disability. * Low-set ears/posteriorly rotated ears * Intellectual deficit as well as learning disabilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacobsen Syndrome
Jacobsen syndrome is a rare chromosomal disorder resulting from deletion of genes from chromosome 11 that includes band 11q24.1. It is a congenital disorder. Since the deletion takes place on the q arm of chromosome 11, it is also called 11q terminal deletion disorder. The deletion may range from 5 million to 16 million deleted DNA base pairs. The severity of symptoms depends on the number of deletions; the more deletions there are, the more severe the symptoms are likely to be. People with Jacobsen syndrome have serious intellectual disabilities, dysmorphic features, delayed development and a variety of physical problems including heart defects. Research shows that almost 88.5% of people with Jacobsen syndrome have a bleeding disorder called Paris-Trousseau syndrome. Jacobsen syndrome is catastrophic in 1 out of every 5 cases, with children usually dying within the first 2 years of life due to heart complications. Signs and symptoms Almost all children with Jacobsen synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metopic Suture
The frontal suture is a fibrous joint that divides the two halves of the frontal bone of the human skull, skull in infants and children. Typically, it completely fuses between three and nine months of age, with the two halves of the frontal bone being fused together. It is also called the metopic suture, although this term may also refer specifically to a ''persistent frontal suture''. If the suture is not present at birth because both frontal bones have fused (craniosynostosis), it will cause a keel-shaped deformity of the skull called trigonocephaly. Its presence in a fetal skull, along with other cranial suture (joint), sutures and fontanelles, provides a malleability to the skull that can facilitate movement of the head through the cervical canal and vagina during delivery. The dense connective tissue found between the frontal bones is replaced with bone tissue as the child grows older. Persistent frontal suture In some individuals, the suture can persist (totally or partl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synostosis
Synostosis (; plural: synostoses) is fusion of two or more bones. It can be normal in puberty (e.g. fusion of the epiphyseal plate to become the epiphyseal line), or abnormal. When synostosis is abnormal it is a type of dysostosis. Examples of synostoses include: * craniosynostosis – an abnormal fusion of two or more cranial bones; * radioulnar synostosis – the abnormal fusion of the radius and ulna bones of the forearm; * tarsal coalition – a failure to separately form all seven bones of the tarsus (the hind part of the foot) resulting in an amalgamation of two bones; and * syndactyly – the abnormal fusion of neighboring digits. Synostosis within joints can cause ankylosis. __TOC__ Clinical significance Radioulnar synostosis is one of the more common failures of separation of parts of the upper limb. There are two general types: one is characterized by fusion of the radius and ulna at their proximal borders and the other is fused distal to the proximal radial e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibulofacial Dysostosis-microcephaly Syndrome
Mandibulofacial dysostosis with microcephaly syndrome, also known as growth delay-intellectual disability-mandibulofacial dysostosis-microcephaly-cleft palate syndrome, mandibulofacial dysostosis, guion-almeida type, or simply as MFDM syndrome is a rare genetic disorder which is characterized by developmental delays, intellectual disabilities, and craniofacial dysmorphisms. Signs and symptoms People with this condition are usually born with congenital microcephaly, the type of microcephaly individuals with this condition exhibit ''progressive microcephaly'', this condition gives the appearance that the head is getting smaller as one ages, this is not true whatsoever; what is actually happening is that the head does not grow at the same rate as the rest of the body. Other craniofacial dysmorphisms include malar hypoplasia, midface and cheekbone hypoplasia, micrognathia, and small abnormally-shaped ears. In some individuals with MFDM syndrome, preauricular tags are present. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleft Lip And Cleft Palate
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 nose. The term orofacial cleft refers to either condition or to both occurring together. These disorders can result in feeding problems, speech problems, hearing problems, and frequent ear infections. Less than half the time the condition is associated with other disorders. Cleft lip and palate are the result of tissues of the face not joining properly during development. As such, they are a type of birth defect. The cause is unknown in most cases. Risk factors include smoking during pregnancy, diabetes, obesity, an older mother, and certain medications (such as some used to treat seizures). Cleft lip and cleft palate can often be diagnosed during pregnancy with an ultrasound exam. A cleft lip or palate can be successfully treated with surgery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine Encephalopathy
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset. The symptoms are exclusively neurological in nature, and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues, especially the cerebrospinal fluid. Glycine encephalopathy is sometimes referred to as "nonketotic hyperglycinemia" (NKH), as a reference to the biochemical findings seen in patients with the disorder, and to distinguish it from the disorders that cause "ketotic hyperglycinemia" (seen in propionic acidemia and several other inherited metabolic disorders). To avoid confusion, the term "glycine encephalopathy" is of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blepharophimosis Intellectual Disability Syndromes
Blepharophimosis intellectual disability syndromes are a group of rare genetic disorders which are characterized by blepharophimosis, ptosis, and intellectual disabilities. These disorders usually follow either autosomal recessive, autosomal dominant, x-linked recessive, or mitochondrial inheritance patterns. Types Oculocerebrofacial syndrome, Kaufman type Oculocerebrofacial syndrome is a very rare autosomal recessive type of BIDS which is characterized by profound intellectual disabilities, cranio-facial dysmorphisms (including blepharophimosis), and other congenital ocular-brain-urogenital-skeletal anomalies. Only 19 cases have been reported in medical literature. Blepharophimosis-intellectual disability syndrome, MKB type This is a rare, X-linked recessive type of BIDS which is characterized by developmental and speech delay, intellectual disabilities, urogenital anomalies, facial dysmorphisms (including blepharophimosis), and autistic-like behavior. Additional findi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bohring–Opitz Syndrome
Bohring–Opitz syndrome (BOS) is a genetic disorder caused by mutations in the ''ASXL1'' gene. Presentation This condition is characterised by craniofacial appearance, fixed contractures of the upper limbs, abnormal posture, feeding difficulties, intellectual disability, small size at birth and failure to thrive. Children with BOS can also have recurring respiratory infections, silent aspiration, sleep apnea, developmental delay, abnormal hair density and length, Wilms' tumors, brain abnormalities, and other issues. Genetics Genetically, de novo truncating mutations in ''ASXL1'' have been shown to account for approximately 50% of Bohring–Opitz syndrome cases. A second gene associated with this condition is the Kelch-like family member 7 ( KLHL7). Diagnosis As some of these features are shared with other genetic syndromes, the diagnosis is made by genetic testing Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Genetics
Medical genetics is the branch of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, while medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counselling people with genetic disorders would be considered part of medical genetics. In contrast, the study of typically non-medical phenotypes such as the genetics of eye color would be considered part of human genetics, but not necessarily relevant to medical genetics (except in situations such as albinism). ''Genetic medicine'' is a newer term for medical genetics and incorporates areas such as gene therapy, personalized medicine, and the rapidly emerging new medical specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coffin–Siris Syndrome
Coffin–Siris syndrome (CSS), first described in 1970 by Dr Grange S. Coffin and Dr E. Siris, is a rare genetic disorder that causes developmental delays and absent fifth finger and toe nails. There had been 31 reported cases by 1991. The number of occurrences since then has grown and is now reported to be around 200. The differential includes Nicolaides–Baraitser syndrome. Presentation * mild to moderate to severe intellectual disability, also called "developmental disability" * short fifth digits with hypoplastic or absent nails * low birth weight * feeding difficulties upon birth * frequent respiratory infections during infancy * hypotonia * joint laxity * delayed bone age * microcephaly * coarse facial features, including wide nose, wide mouth, and thick eyebrows and lashes Causes Disease can be inherited as an autosomal dominant trait, however most cases of CSS appear to be the result of a de novo mutation. This syndrome has been associated with mutations in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
