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Contractural Arachnodactyly
Congenital contractural arachnodactyly (CCA), also known as Beals–Hecht syndrome, is a rare autosomal dominant mwod:congenital, congenital connective tissue disorder. As with Marfan syndrome, people with CCA typically have an arm span that is greater than their height and Arachnodactyly, very long fingers and toes. However, Beals and Hecht discovered in 1972 that, unlike Marfan's, CCA is caused by mutations to the Fibrillin 1, fibrillin-2 (''FBN2'') gene rather than the fibrillin-1 (''FBN1'') gene. Signs and symptoms Signs and symptoms of CCA often resemble those of Marfan syndrome, despite the two syndromes' different causes. CCA is characterized by contractures of varying degrees, mainly involving the large joints, which are present in all affected children at birth. The contractures may be mild and tend to improve over time, but permanently bent fingers and toes (camptodactyly) are almost always present. In addition to long fingers and toes and a tall, slender body, people with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Dominant
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 first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
