Inheritance patterns, consanguinity & risk for asthma.

BACKGROUND & OBJECTIVES Family history is an important risk factor for the development of asthma, contingent upon genetic and environment interaction. Since there is paucity of data on asthma inheritance in Indian population, the present study was undertaken to investigate the inheritance patterns of asthma and the effect of family history and consanguineous marriage on asthma inheritance. METHODS A total of 200 families, 100 index children and 100 index adults with clinically diagnosed asthma, along with 400 non-asthmatic children and adults as controls were selected for the present study. Information about the family history of each patients and controls was collected and analyzed pedigrees were also constructed. RESULTS A history of asthma in any member of the family was observed in 44.5 per cent of cases and 5.3 per cent of controls (P<0.001). A differential risk of developing asthma was noted in family history of asthma in different first and second degree relatives of children and adult patients. Consanguineous marriage was also noted in parents in 24.5 per cent of cases and 12.3 per cent of controls (P<0.001). The most common mode of asthma inheritance was recessive. INTERPRETATION & CONCLUSIONS Our results showed that consanguineous marriage and family history of asthma are important determinants in the development of asthma in the offspring.