Chromosomal abnormalities in mentally retarded children in the Konya region - Turkey

Etiology of mental retardation is diverse. 120 Students from 11 special tra ining, education, and rehabilitation subclasses were investigated cytogenet ically For determining the contribution of chromosomal abnormalities to mil d mental retardation. 23 of the 120 children (19%) had chromosomal abnormal ities: thirteen cases a classical trisomy 21 (the male: Female ratio was 9: 4), three a balanced autosomal reciprocal translocation, one a pericentric inversion of chromosome 9, and six fragile-X syndrome (The male: female rat io was 5:1).