Martin-Bell fragile X syndrome

The 'fragile' X chromosome in the Martin-Bell-Renpenning syndrome and in males with other forms of familial mental retardation.

A clinical and cytogenetic study has been made of subjects from families who have possible X linked mental retardation. The families were distinguished as those with a clinical diagnosis of Renpenning syndrome and those with other behavioural or physical abnormalities obviating such a diagnosis. All subjects with REnpenning syndrome carried a fragile Xq27-28 chromosome in more than 4% of their ...

The fragile X syndrome.

We have begun to appreciate that the extent of this disorder is much wider than merely mental retardation. It is also a common cause of learning and emotional problems in mildly affected female carriers with normal IQs. These children present an enormous challenge to all child-care providers, be they in medicine, education, or in various therapy disciplines. Early identification is essential, a...

Fragile X syndrome.

Fragile X syndrome

Fragile X syndrome occurs as a result of a mutation of the fragile X mental retardation 1 (FMR1) gene on the bottom of the X chromosome (Pic. 1), which encodes fragile X mental retardation protein (FMRP). This protein, most commonly found in the brain, is essential for normal cognitive development and female reproductive function. The CGG triplet that means gene segment consisting of a cytosine...

Fragile X Syndrome

groups with asthma. Thus the scientist must weigh the advantages of performing genetic studies in small, historically isolated populations with the potential disadvantage of being unable to eventually generalize the studies’ results. SEE ALSO Genetic Drift; Hardy-Weinberg Equilibrium; Inbreeding; Linkage and Recombination; Mapping; Population Bottleneck; Population Genetics; Tay-Sachs Disease.