Consanguinity in the genomic era—Requirement of focused counseling

In the early stages of civilization, due to small founding groups and restricted mate choices, substantial inbreeding was inevitable. Presently, it is estimated that 10.4% of the global population practices consanguinity, with 30%-60% prevalence in north and sub-Saharan Africa, the Middle East, and west, central, and south Asia. Apart from this, endogamy is also very high, as marriages within the clan (brotherhood or Biraderi), tribe, and caste system are still prevalent. This centuries-old custom is an established tradition deeply embedded in the socio-cultural fabric of several societal and ethnic groups. It is well acknowledged that consanguineous/endogamous unions increase autosomal recessive disorders, with these being ≈3.5% higher than in nonconsanguineous couples. Genetic counseling is an established approach to addressing the challenges of estimating the risk of genetic morbidity and mortality in the offsprings of consanguineous/endogamous couples. In the genomic era, high-throughput next-generation genomic technologies need to be diligently applied to identify disease-causing founder mutations, sequence variants, and copy number variants useful for screening the whole community and selectively use for carrier identification, premarital counseling, reproductive counseling, and prenatal testing for prevention. In addition, this will provide an opportunity to explore the role of common and rare recessive gene variants in the etiology of complex diseases, which could be used to reduce life-time risks through targeted health surveillance and prophylactic interventions including dietary changes and lifestyle modification. Genetic counseling in communities and families with consanguinity has to be catered based on their culture, religion, and personal beliefs.