Published: 2020-12-23

Having a common ancestor; significance of consanguinity and genetic diseases

Madhurasree Nelanuthala, Brahmapreet Kaur, Vinod Ingale, Suvarna Magar, Pradnya Joshi


Background: Consanguinity is prevalent in India, which is one of the high-risk factors for increased risk of single gene diseases. Global developmental delay is heterogeneous group of genetic diseases which includes chromosomal and single gene diseases. The aim of the study is to determine impact of consanguinity on these 2 groups of diseases.

Methods: A retrospective review of children coming to genetic OPD with global developmental delay (GDD) and children who were proven inborn errors of metabolism (IEM) was done. Presence of consanguinity or its absence was noted in all the children in both groups.

Results: Out of 194 cases visited to genetic OPD, 103 (54%) of the patients were product of consanguineous marriage and 91 (46%) were product of non-consanguineous marriage. Out of 103 cases born of consanguineous marriage, 59 (57.3%) were GDD and out of 91 children who were born of non-consanguineous, 70 (68.35%) were having GDD. The difference was statistically significant with p value of 0.003. Out of 103 cases which were product of consanguineous marriage 44 (42.7%) were IEMs and out of 91 children who were product of non-consanguineous, 21 (23%) were having IEMs. The difference was statistically significant with p value of 0.004.

Conclusions: Genetic drift or founder mutations need to be considered in Indian communities, where small sub-communities are genetically isolated pools and can have distinct genetic diseases belonging to particular communities not having impacted by consanguinity. Consanguinity increases risk of autosomal recessive diseases like inborn errors of metabolism.


Consanguinity, Inborn errors of metabolism, Global developmental delay

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Maheswari K, Wadhwa L. Role of consanguinity in paediatric neurological disorders. Int J Contemporary Pediatr. 2016;3(3):939-42.

Bittles AH, Black ML. Evolution in health and medicine Sackler colloquium: Consanguinity, human evolution, and complex diseases. Proceedings of the National Academy of Sciences of the United States of America. 2010;107(1):1779-86.

Fareed M, Afzal M. Evidence of inbreeding depression on height, weight, and body mass index: a population-based child cohort study. Am J Hum Biol. 2014;26(6):784-95.

Ben-Omran T, Al Ghanim K, Yavarna T, El Akoum M, Samara M, Chandra P et al. Effects of consanguinity in a cohort of subjects with certain genetic disorders in Qatar. Molecular Genetics Genomic Med. 2020;8(1):e1051.

Nalini A, Gayathri N, Yasha TC, Ravishankar S, Urtizberea A, Huehne K et al. Clinical, pathological and molecular findings in two siblings with giant axonal neuropathy (GAN): Report from India. Eur J Med Genet. 2008;51:426-35.

Bindu PS, Desai S, Shehanaz KE, Nethravathy M, Pal PK. Clinical heterogeneity in Hallervorden-Spatz syndrome: A clinicoradiological study in 13 patients from South India. Brain Dev. 2006;28:343-7.

Bittles AH. The impact of consanguinity on the Indian population. Ind J of Human genetics. 2002;8(2):45-51.

Ramegowda S, Nallur BR. Parental consanguinity increases congenital heart diseases in South India. Ann Human Biol. 2006;33(5/6):519-28.

El Mouzan MI, Al Salloum AA, Al Herbish AS, Qurachi MM, Al Omar AA. Consanguinity and major genetic disorders in Saudi children: a community-based cross-sectional study. Ann Saudi Med. 2008;28(3):169-73.

Waters D, Adeloye D, Woolham D, Wastnedge E, Patel S, Rudan I. Global birth prevalence and mortality from inborn errors of metabolism: a systematic analysis of the evidence. J Glob Health. 2018;8(2):021102.