Abstract
Consanguinity is most common phenomenon in Muslim countries, especially in Pakistan, causing physical and mental
disabilities in children. The aim of this study was to elaborate the consanguinity effects in Pakistani population by
karyotyping method. Blood samples from consented (n = 68) mentally retarded individuals were collected from
handicapped children of special schools in Islamabad. The samples were processed and stained for karyotype analysis
and images were obtained by high-quality microscope. Karyotyping of 68 mentally retarded individuals were
performed to determine the genetic causes. Among the total karyotypes, 24 (35.28 %) were found abnormal, showing
chromosomal aberrations. Out of these 24 abnormal karyotypes, 12 cases (17.64%) of trisomy were found in the form
of Down’s syndrome being the most frequent. In rest of the population, 5 children (7.35%) were monosomic (Turner
syndrome), 5 (7.35%) were mosaic turner syndrome, only 1(1.47%) from each of Klinefelter and Cri du Chat
syndrome. Finally, ratio of handicapped children having consanguine and non-consanguine origin was found to be
61.76 and 38.24%, respectively. Our findings demonstrate that consanguinity is contributing towards the origin of
abnormalities in Pakistani population more than the cross marriages. By creating a sense of understanding in the people
about the drawbacks of consanguinity, severe genetic abnormalities can be avoided.
