[Incidence of oligophrenia with fragile X chromosome (FraXq27)].

The study of 50 retarded males imbezilitat and idiots, and 100 males with oligophrenia-debilitat in 16-18 years. Severe macroorchism (1.8-4.5 times more, then anthropometric norma for this years) was found at 5 males in first group (10%), and in 8 males in second group (8%). The karyotype was study in 4 males with macroorchism. In 9-15% cells FraX (q27) was found. These data were extrapolated to 600 retarded children preschool and school age. The frequency of oligophrenia with FraX (q27) among all retarded males-8.5 +/- 1.5; retarded heterozygous females among all retarded girls-5.0 +/- 1.3; incidence of oligophrenia with FraX (q27) among all males in population-1:1000; all heterozigous for this gene among all females in population-7:750; retarded heterozygous females in all girls-1:2250 were established.