Congenital Hypothyroidism: Recent Indian data

Sir,

We read with great interest the review article by Agarwal et al. on congenital hypothyroidism (CH).[1] The author mentions that the prevalence of CH in India is 1 in 2640 based on the study was done by Desai et al. in 1998.[2] For the benefit of the readers we would like to add that significant information regarding the prevalence of CH has been accumulated in the last few years from our country and many of them point towards higher incidence of CH in India. The probable reasons for this increased prevalence could be due, as discussed in the article, to improved testing strategies, increasing numbers of preterm births[1] or the actual incidence of a condition that was not studied in a large scale in the second most populous country in the world. The other studies from India quote a prevalence of 1 in 1985 from Hyderabad[3] and 2.1 in 1000 from Kochi.[4] Both these studies were hospital-based with relatively small sample sizes. In another study recently from UP, the prevalence of CH was reported to be approximately 1:1221.[5] The first multi-centric study screening above 1 lakhs neonates born throughout India was launched by Indian Council of Medical Research (ICMR) National Task Force Team on New Born Screening (NBS) at AIIMS New Delhi (2007–2012) and the preliminary results reveal a much higher incidence of CH all over India at 1 in 1172, particularly in south Indian population (1 in 727). Results have been released by ICMR team on March 15, 2013 presided by Tamil Nadu Government Deputy Dierector of Medical Education.[6] In another review by Sundararaman the result of the pilot study of the above project was quoted to be 1.6 in 1000.[7] The detailed report of the above mentioned ICMR study is likely to be published in the near future. As members of the Chennai centre of the ICMR study on NBS in India, we thought it would be appropriate and useful to share and highlight the initial published findings with our journal readers.