Rett Syndrome
Rett syndrome affects brain development, typically causing severedyspraxia (severe motor impairment).Severity varies widely. Some affectedgirls and women, given a suitable means of communication, display normalintelligence. Others may develop intellectual disabilities.Seizures are common. About 50% are unable to walk. The syndrome isseen mostly in females, because for male fetuses it is often lethalbefore birth.
90% of cases appear to be caused by mutations in methyl CpG binding protein 2(MeCP2), a gene in the X chromosome. In at least 95% of Rett syndrome cases,the cause is a de novo mutation in the child. That is, it is not inheritedfrom either parent. The parents' MeCP2 genes are normal. Rett syndromepatients are fertile but unlikely to have children. Therefore the mutationsare rapidly lost from the human gene pool.
More than 60 mutations have been identified that cause Rett syndrome. 65% aresingle nucleotide point mutations C ==> T. Three common ones occur in thedomain that binds methylated DNA: R106W, R133C, and T158M.
PDB code: 3c2i.
by Eric Martz, University of Massachusetts, 2012
Thanks to Kim Johnson (R255X) and Jill Johnson (Australia),and to Susan Irby (New Jersey, USA)for their advice which made this page more accurate and appropriate.
