Mutation Spectrum of β-Thalassemia in Some Ethnic Groups of North Maharashtra, India

Abstract

Beta-thalassemia is the most common inherited single-gene disorder in the world, caused by more than 200 known mutations in the HBB gene. In India, the average prevalence of β-thalassemia carriers is 3-4%. Several ethnic groups have a much higher prevalence, about 8% in the tribal groups, according to the 2011 census. The study’s main goal is to identify common β-thalassemia mutations and the frequencies of different haplotypes in various communities in North Maharashtra. Nashik district had the highest prevalence of β-thalassemia (34%), followed by Ahmednagar (29%), Jalgaon (16%), Dhule (14%), and Nandurbar (7.0%). Prevalence of β-thalassemia was highest in the schedule caste community (SC) (48%), followed by (17%) in Muslims, (14%) in other backward classes (OBC), (13%) in Schedule Tribe (ST), and (8.0%) in the general population The six most common β-thalassemia mutations detected in this study are IVS 1 > 5 (G→C), Cd 15(G→A), Cd 41/41 (-TCTT), Cd 8/9(+G), IVS 1 > 1(G→T) and Cap + 1(A > G). Among these mutations, IVS 1 > 5 (G > C) was the most common type of mutation found in β-thalassemia patients in the North Maharashtra population. Type-I haplotype was the most prevalent among all communities. Nashik and Ahmednagar districts were highly affected by β-thalassemia. Among different ethnic groups, the SC and Muslim communities were the worst affected with a higher proportion of β-thalassemia and increased frequency of mutations.

Keywords:

• Beta-thalassemia
• haplotype analysis
• HBB gene
• MARMS-PCR
• RFLP-PCR

Acknowledgements

Authors are thankful to University Grant Commission (UGC), New Delhi, India for providing financial support. We are also grateful to all the donors of the blood samples. We would like to thank Civil Hospital Ahmadnagar, Civil Hospital Jalgaon and Civil Hospital Nandurbar for providing blood samples of β-thalassemia.

Authors contributions

RK was involved in sample collection, experimentation and writing of primary draft of manuscript. SAA helps in experimentation and writing of primary draft. MO and SS provides valuable suggestion during the study and helps in finalizing the draft. VW conceptualizes the study, communicates with Institutional Human Ethics Committee for permission and helps in finalizing the draft.

Disclosure statement

Dr. Sadayappan provides consulting and collaborative research studies to the Leducq Foundation (CURE-PLAN), Red Saree Inc., Greater Cincinnati Tamil Sangam, Novo Nordisk, Pfizer, AavantiBio, AstraZeneca, MyoKardia, Merck and Amgen, but such work is unrelated to the content of this article. No other authors declare any conflicts of interest.

Additional information

Funding

UGC-CAS, DRDP, and DST-PURSE are acknowledged for partial financial support.