Chromosome survey in some clinical disorders in Northern Nigeria II : Neuro-developmental retardates

Analysis of metaphase chromosomes, obtained from cultured peripheral blood leucocytes was carried out on fifty selected subjects with developmental and, or mental retardation. Eight of the fifty subjects had chromosome abnormalities that could account for their retardation; one subject showed mosaicism for a group C ring chromosome, whereas the remaining seven were trisomic for chromosome 21 (four as regular trisomies, two as mosaics and one as a GIG translocation). The findings in this study illustrates the importance of chromosome analysis in the evaluation of individuals with developmental problems.