Prevalence and genetic mechanisms of neurological and gynaecological changes in women carrying small FMR1 expansions

点击翻译按钮获取中文摘要

Fragile X syndrome is one of the commonest genetic forms of mental retardation. The abnormal gene is passed from mothers to their sons or daughters, on their X chromosome. The gene abnormality is unstable, tending to worsen each time it is passed on. But if this gene abnormality is passed from fathers to their daughters, it does not worsen. Therefore, grandfathers of the affected children on their mother's side, as well as the mothers, may carry a mildly abnormal gene (a premutation), insufficient to cause mental retardation. However, it has recently been discovered that these grandfathers may develop a syndrome (FXTAS) of tremor, incoordination, slowness of movements and mild dementia in their later years. Women were thought to be protected, as they carry TWO X chromosomes, one of which is normal even if the other has a premutation. But very recent reports suggest that they may also develop the FXTAS syndrome, as well as early menopause. This study aims to see how common and severe these abnormalities are in women who carry the premutation, using clinical, MRI and electronic measurements, and to relate the abnormalities to the severity of the gene malfunction and familial predisposition.