A Family Study of Consanguinity in Children with Intellectual Disabilities in Barwani, India

ABSTRACT

Background: Intellectual disability (ID) can be inherited in families through consanguineous marriage. The ID in an individual can be associated with the ID, epilepsy, and mental illness in their parents. Such connections can be seen more closely among consanguineous marriages in tribal and nontribal population in India. Objective: This study shows a few common patterns of the consanguineous relationship in the parents of children with ID in India. Materials and Methods: This is a case series research design. Extreme or deviant case sampling was applied. Data were collected in homes, camps, and clinical settings in the Barwani district of Madhya Pradesh, India. The patterns of consanguineous marriages and the relationship between children with ID and their relatives with ID, epilepsy, and mental illness were analyzed and reported with pedigree charts. Results: Multiple patterns of consanguineous marriages in tribal and nontribal populations were observed. ID was found to be associated in children with their relatives of the first, second, and third generations. Conclusion: ID may inherit in individuals from their relatives of the first, second, and third generations who have ID, epilepsy, or mental illness and married in the relationship. Appropriate knowledge, guidance, and counseling may be provided to potential couples before planning a consanguineous marriage.

KEYWORDS:

Consanguinity - family history - intellectual disability

• REFERENCES

• 1 Rauch A, Wieczorek D, Graf E, Wieland T, Endele S, Schwarzmayr T. et al. Range of genetic mutations associated with severe non-syndromic sporadic intellectual disability: An exome sequencing study. Lancet 2012; 380: 1674-82
• 2 Kaufman L, Ayub M, Vincent JB. The genetic basis of non-syndromic intellectual disability: A review. J Neurodev Disord 2010; 2: 182-209
• 3 Ropers HH. Genetics of intellectual disability. Curr Opin Genet Dev 2008; 18: 241-50
• 4 Chelly J, Khelfaoui M, Francis F, Chérif B, Bienvenu T. Genetics and pathophysiology of mental retardation. Eur J Hum Genet 2006; 14: 701-13
• 5 McLaren J, Bryson SE. Review of recent epidemiological studies of mental retardation: Prevalence, associated disorders, and etiology. Am J Ment Retard 1987; 92: 243-54
• 6 Hussain R, Bittles AH, Sullivan S. Consanguinity and early mortality in the Muslim populations of India and Pakistan. Am J Hum Biol 2001; 13: 777-87
• 7 Basu SK. Effect of consanguinity among North India Muslims. J Popul Res 1975; 2: 57-68
• 8 Coe BP, Girirajan S, Eichler EE. The genetic variability and commonality of neurodevelopmental disease. Am J Med Genet C Semin Med Genet 2012; 160C: 118-29
• 9 de Ligt J, Willemsen MH, van Bon BW, Kleefstra T, Yntema HG, Kroes T. et al. Diagnostic exome sequencing in persons with severe intellectual disability. N Engl J Med 2012; 367: 1921-9
• 10 Najmabadi H, Hu H, Garshasbi M, Zemojtel T, Abedini SS, Chen W. et al. Deep sequencing reveals 50 novel genes for recessive cognitive disorders. Nature 2011; 478: 57-63
• 11 Bittles AH. The impact of consanguinity on the Indian population. Indian J Hum Genet 2002; 8: 45-51
• 12 Nagarkar A, Sharma JP, Tandon SK, Goutam P. The clinical profile of mentally retarded children in India and prevalence of depression in mothers of the mentally retarded. Indian J Psychiatry 2014; 56: 165-70
• 13 Hou JW, Wang TR, Chuang SM. An epidemiological and aetiological study of children with intellectual disability in Taiwan. J Intellect Disabil Res 1998; 42 (Pt 2) 137-43
• 14 Shawky RM, Elsayed SM, Zaki ME, Nour El-Din SM, Kamal FM. Consanguinity and its relevance to clinical genetics. Egypt J Med Hum Genet 2013; 14: 157-64
• 15 Verma IC, Bijarnia S. The burden of genetic disorders in India and a framework for community control. Public Health Genomics 2002; 5: 192-6
• 16 Rajangam S, Devi R. Consanguinity and chromosomal abnormality in mental retardation and or multiple congenital anomaly. J Anat Soc India 2007; 56: 30-3
• 17 Madhavan T, Narayan J. Consanguinity and mental retardation. J Intellect Disabil Res 1991; 35: 133-9
• 18 Krishnasubha S, Lakshmikalpana V, Ramesh M, Sudhakar G. A case-control study on risk factors of mental retardation from an urban area of North Coastal Andhra Pradesh. J Life Sci 2010; 2: 93-8
• 19 Madhavan T, Narayan J. Epilepsy and mental retardation. Indian J Psychiatry 1992; 34: 12-7
• 20 Amudha S, Aruna N, Rajangam S. Consanguinity and chromosomal abnormality. Indian J Hum Genet 2005; 11: 108-10
• 21 Saggar AK, Bittles AH. Consanguinity and child health. Pediatr Child Health 2008; 18: 244-9
• 22 Bittles AH, Hussain R. An analysis of consanguineous marriage in the Muslim population of India at regional and state levels. Ann Hum Biol 2000; 27: 163-71
• 23 Hussain R, Bittles AH. Sociodemographic correlates of consanguineous marriage in the Muslim population of India. J Biosoc Sci 2000; 32: 433-42
• 24 Bittles AH, Coble JM, Rao NA. Trends in consanguineaous marriage in Karnataka, South India, 1980-89. J Biosoc Sci 1993; 25: 111-6
• 25 Reddy PH, Modell B. Consanguinity and reproductive behaviour in a tribal population ’the Baiga’ in Madhya Pradesh, India. Ann Hum Biol 1995; 22: 235-46
• 26 Rao PS, Inbaraj SG, Jesudian G. Rural-urban differentials in consanguinity. J Med Genet 1972; 9: 174-8