Fragile X chromosome، the syndrome is undoubtedly X- linked، it can not unequivocally be assigned to whether the dominant or the recessive category
الملخص
This study included five Iraqi families from four provinces, many members who suffered from congenital fragile X chromosome. Five family pedigrees were drawn up very clearly to follow the pattern of fragile X chromosome. The study showed that there is marked discrepancy in the sex ratio, with only boys affected. Females are affected only if they were homozygous, Heterozygous (carrier) females were clinically normal but transmitted the disease to 35% of their sons, and there i s one in two risks that their daughters too were carriers. The fragile X chromosome was never transmitted directly from affected father to his sons but through his daughters to next generation indicating the skip-generation of inheritance. This study suggeststhatfragile X chromosome is inherited as X chromosome linked disease.
