The most common heritable form of mental retardation. Fragile X syndrome is due to a dynamic mutation (a trinucleotide repeat) at an inherited fragile site on the X chromosome; therefore, it is an X-linked disorder. Characteristics of fragile X syndrome in boys may include, in addition to mental impairment, prominent or long ears, a long face, dela [..]

A hereditary mental disorder, partially explained by genomic imprinting and the addition of nucleotides to a triplet repeat near the end of an X chromosome.

The most common inherited cause of mental retardation; takes its name from the appearance of the stained X chromosome under a microscope – there is a site near the end of this chromosome that does not stain, indicating its fragility. The gene in the fragile region is important in making a special protein needed by developing brain cells.

Fragile X syndrome is a hereditary disorder affecting mostly males. Symptoms include mental retardation, distinctive facial features, and poor muscle tone. The syndrome is caused by mutations in a gene on the X chromosome. Since males have a single copy of the X chromosome, they show symptoms if gene on their X chromosome is mutated. Females have a [..]

A condition that is a frequent cause of inherited intellectual disability; produced by a fragile site on the X chromosome that seems prone to breaking because the DNA there is unstable.

A diagnosed inherited condition, caused by a 'fragile' or broken site on the X chromosome, resulting in mental and physical impairment.

A condition characterized genotypically by Mutation of the distal end of the long arm of the X Chromosome (at Gene loci FRAXA or FRAXE) and phenotypically by cognitive impairment, hyperactivity, Seizu [..]

A condition characterized genotypically by mutation of the distal end of the long arm of the X chromosome (at gene loci FRAXA or FRAXE) and phenotypically by cognitive impairment, hyperactivity, SEIZU [..]

One of the most common causes of inherited mental retardation and neuropsychiatric disease in human beings.

A genetic condition caused by a spontaneous partial break in the long arm of the X chromosome. Measurement of testes in males and a chromosome analysis helps confirm the diagnosis. There are often ver [..]

A reproductive disorder characterized by an almost broken X chromosome, which has a tip hanging by a weak thread. It is the most common cause of inherited mental retardation. Tests for the broken chromosome are accurate only about 75% of the time. Some healthy people may have fragile X chromosomes without knowing it, and may pass the condition to c [..]