Genetics of consanguinity and inbreeding in health and disease

Context: Inbreeding increases the level of homozygotes for autosomal recessive disorders and is the major objective in clinical studies. The prevalence of consanguinity and the degree of inbreeding vary from one population to another depending on ethnicity, religion, culture and geography. Global epidemiological studies have revealed that consanguineous unions have been significantly associated with increased susceptibility to various forms of inherited diseases. Objective: The study aimed to determine the role of consanguinity in human health and to highlight the associated risks for various diseases or disorders. Methods: PubMed and Google Scholar search engines were used to explore the published literature on consanguinity and its associated risks using the key words consanguinity, prevalence, inbreeding depression, coefficient of inbreeding, child health, mortality, human health, homozygosity and complex diseases in different combinations. The studies were screened for eligibility on the basis of their epidemiological relevance. Results: This comprehensive assessment highlights the deleterious consequences in populations with a higher prevalence of consanguinity among different countries worldwide. Conclusions: To avoid the inbreeding load there is the need to improve socioeconomic and educational status and to increase public awareness of reproductive health and anticipated deleterious effects. Pre-marital and pre-conception counselling of consanguineous populations should be an integral part of health policy to train people and make people aware of its harmful consequences. Furthermore, runs of homozygosity (ROH) and whole-exome sequencing (WES) are useful tools in exploring new genomic signatures for the cause of inbreeding depression.