Estimating the inbreeding depression on cognitive behavior: a population based study of child cohort. PLoS One. 2014; 9: e109585. doi: 10.1371/journal.pone.0109585 PMID

Background: Cognitive ability tests are widely assumed to measure maximal intellectual performance and predictive associations between intelligence quotient (IQ) scores and later mental health problems. Very few epidemiologic studies have been done to demonstrate the relationship between familial inbreeding and modest cognitive impairments in children. Objective: We aimed to estimate the effect of inbreeding on children’s cognitive behavior in comparison with non-inbred children. Methodology: A cohort of 408 children (6 to 15 years of age) was selected from inbred and non-inbred families of five Muslim populations of Jammu region. The Wechsler Intelligence Scales for Children (WISC) was used to measure the verbal IQ (VIQ), performance IQ (PIQ) and full scale IQ (FSIQ). Family pedigrees were drawn to access the family history and children’s inbred status in terms of coefficient of inbreeding (F). Results:We found significant decline in child cognitive abilities due to inbreeding and high frequency of mental retardation among offspring from inbred families. The mean differences (95 % C.I.) were reported for the VIQ, being 222.00 (224.82, 219.17), PIQ 226.92 (229.96, 223.87) and FSIQ 224.47 (227.35, 221.59) for inbred as compared to non-inbred children (p.0.001). The higher risk of being mentally retarded was found to be more obvious among inbred categorie