Table 1.

Epidemiological information on beta-thalassaemia and overall haemoglobin disorders in India

India	PHGDBa	Sinha et al.20
Beta-thalassaemia carrier frequency	4.6%	3–4%21
No. of beta-thalassaemia carriers	49.0 million	35.1–46.8 million
Beta-thalassaemia births per year	6000b	10 000–15 00022–24
Pathological haemoglobin disordersc births per year	32 500b	32 400
Pathological haemoglobin disordersc birth rate	1.23/1000	1.2/10001

^aModell: parental consanguinity factored in (p² + Fpq) + 2(pq − Fpq) + (q² + Fpq) = 1, where p is the frequency of variable 1, q the frequency of variable 2 and F the population coefficient of parental consanguinity.²⁵

^bModell estimates are the most conservative that are permitted by the data available (i.e. believed to be minimum estimates).²⁵

^cPathological haemoglobin disorders are sickle cell disease, beta-thalassaemia, alpha zero thalassaemia and Hb H disease.