title: The female and the fragile X. A study of 144 obligate female carriers.
abstract: In the present report we summarize our data on 144 obligate female carriers. The clinical and cytogenetic data are reviewed and discussed. In more than 30% of heterozygotes mental development is borderline to subnormal, and they may also present psychiatric disturbances of which psychotic behaviour is the most frequent. Partial phenotypic expression is present in 28% of the carriers, and is more frequent in the mentally subnormal. Repeated fragile X screening remains negative in more than 50% of the patients. This results in great difficulties in accurate genetic counseling of the individual female at risk. In all females with partial clinical expression fragile X screening is positive. Fragile X carriers have a high fertility. A fourfold increase in twinning is observed and this may be an indication of a disturbed cortico-hypothalamic-hypophyseal axis.
mesh_terms: D000328:Adult; D000368:Aged; D005145:Face / Q000002:abnormalities; D005260:Female; D005298:Fertility; D005600:Fragile X Syndrome / Q000235:genetics* / Q000523:psychology; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D006579:Heterozygote; D006801:Humans; D007360:Intelligence; D008875:Middle Aged; D010641:Phenotype; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D014427:Twins