Prevalence of Cousin Marriage among Parents of Intellectually Disabled and Normal Children and Its Association with Intellectual Disability

Cousin Marriages provide a good opportunity to latent and recessive genes to express themselves and cause various disabilities, such as intellectual disability. Hence, avoiding them may prevent such disabilities. The purpose of this research was to study the prevalence of cousin marriages among the parents of intellectually disabled and normal children and to identify its association with intellectual disability.
A correlational retrospective study was conducted. 467 couples with normal children were selected by cluster sampling from primary, secondary and high schools in Ardebil. Moreover, 433 couples with exceptional children were identified. Among the latter’s children, 238 intellectually disabled were randomly selected. Chi-square was used to determine the frequency of cousin marriages through descriptive statistics and to establish the association between cousin marriages and the birth of normal and intellectually disabled children.
According to the descriptive data 107 of 238 (96.44%) parents of intellectually disabled children and 88 of 467 (84.18%) parents of normal children were cousins. Data analysis with chi-square showed a significant association between cousin marriages and the birth of intellectually disabled children (χ2=54.31, p Cousin Marriage plays an important role in the incidence of intellectual disability through recessive genes. Therefore, couples need to be aware of the consequences of cousin marriage and should receive genetic counseling.