Incidence
In most countries it occurs in approximately 1 in 25,000 to 40,000 live-births in the general population. However, in countries with high rates of consanguineous marriages i.e. marriage between individuals who are closely related, the incidence is estimated up to 1 in 2500 live-births. In India so far there is no prevalence study undertaken but it is thought to be much commoner than in general population.Â
In most countries it occurs in approximately 1 in 25,000 to 40,000 live-births in the general population. However, in countries with high rates of consanguineous marriages i.e. marriage between individuals who are closely related, the incidence is estimated up to 1 in 2500 live-births. In India so far there is no prevalence study undertaken but it is thought to be much commoner than in general population.Â