Background and Objective: Consanguinity increases the incidence of genetic disorders. The frequency of consanguinity varies in different societies. There was no data regarding the frequency of consanguinity in Zanjan province. This study aimed to describe the prevalence of consanguineous unions in the parents of children with genetic disorders and its related factors in Zanjan, Iran.
Materials and Methods: This cross-sectional study included children with genetic diseases referring to the medical genetics clinic in Zanjan's Musavi Hospital during 2014-2018. Data including consanguineous unions in families (up to three previous generations), types of genetic illnesses, child and parents' age, parental educational level, and occupation were collected and analyzed using descriptive statistics, independent t-test, and chi-square test.
Results: Of the 87 children, 41 (47.7%) were male, and 50 (59.5%) resided in urban areas. The mean age of the children was 6.5 years. The educational level of 56.6% of fathers and 50.6% of mothers were highschool diploma or higher. The parents of 44 children (51.8%) had consanguineous unions. The most common type of consanguineous union was between first cousins. The nature of the genetic disorders in 63 (72.4%) of children was molecular. The proportion of consanguinity was significantly higher in parents of children with molecular than chromosomal disorder (P<0.0001). Consanguinity had also a significant relationship with the children's age (P=0.04).
Conclusion: This study's outcomes illustrate that parents of more than half of children with genetic disorders had consanguinity and the frequency of consanguinity was more common in parents of children with molecular disease than chromosomal disorder. Given that, it is necessary to avoid consanguineous marriage as much as possible, and families with a history of molecular genetic disease, should be informed of the possible consequences.