Subhamoy Dastidar, Co-Founder and Director of Lilac Insights, discusses the burden of inborn errors of metabolism (IEMs) in India and the future for it
Pregnancy is a transformative and joyful experience for almost all expectant parents and their families. However, with all the celebrations, it’s important to be aware of a baby’s health, especially when it comes to detecting irreversible disorders such as congenital hypothyroidism, G6PD, congenital metabolic disorders, or IEM, which can be diagnosed and prevented through a simple blood test at birth. Testing for such disorders at birth is called Newborn Screening, or NBS.
Exposure to IEMs and other conditions
NBS is the process by which babies are screened right after birth for disorders that cause serious illness or death if not treated early. Below is a glimpse of the data available in India on the various diseases found in newborns.
- The incidence of IEMs in newborns is approximately 1/1000. IEMs account for approximately 15 percent of total NICU admissions annually.
- There is a prevalence of congenital hypothyroidism with 1 in 1700 having congenital adrenal hypothyroidism affecting 1 in 2575 and amino acid disorders predominate in 1 in 3600 newborns.
- G6PD deficiency is the most common genetic disorder in India. Studies have reported 2 percent to 27.9 percent in different communities.
- About 4/1000 to 5/1000 newborns suffer from hearing impairment and may have congenital heart defects.
- Galactosemia, caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase, affects 4 percent of children with neonatal cholestasis syndrome.
According to these data, over a few lakh children in India have metabolic-genetic disorders. A recent study showed that only 2 percent of cases detected by NBS had clinically serious consequences, compared to 42 percent of cases detected clinically. Delay in diagnosing congenital metabolic disorder or other conditions such as hypothyroidism, G6PD deficiency, etc. can lead to severe intellectual disability, learning disabilities, autism, dyslexia, behavioral problems, and academic backwardness later in life. In severe cases, sudden infant death syndrome (SIDS) can occur. There is also a significant financial and emotional burden on parents to diagnose, treat, and manage these disorders.
Therefore, timely and accurate diagnosis at the time of birth is necessary for prevention. In addition to being inexpensive, newborn screening reduces parental stress and improves the quality of life for the baby and family.
Viability and importance of NBS in the National Health Program
In developed and developing countries in the Asia-Pacific region, NBS programs for a number of metabolic-genetic disorders have been successfully implemented over the past few decades.
In 2008, ICMR launched an NBS program to screen 100,000 newborns for CH and CAH in the 5 metropolitan areas of Chennai, Delhi, Hyderabad, Kolkata and Mumbai. In 2011, the National Neonatology Forum recommended CH, CAH and G6PD screening for all newborns in India.
Many small pilot projects have started in the past. Among these, Chandigarh program, Kerala State NBS program and Goa NBS program have done some commendable work. In 2007, Chandigarh launched NBS for CAH, CH and G6PD. In 2008, Goa introduced mandatory extended NBS for all newborns. In 2009 West Bengal and in 2011 Gujarat approved the launch of large-scale NBS programs that have yet to be implemented.
India also lacked a recognized advocate to advocate for NBS making it a universal benefit in India.
Current status and future of the universal NBS program
Public studies recommend that universal screening programs should include two to four disorders. Currently, private NBS programs have taken the lead with packages to detect three disorders into a comprehensive set (for 50+). With 52 percent of births in India occurring in public hospitals, public NBS screening programs have the potential to achieve universal screening.
With some limited screening programs, there is now greater awareness of the benefits of NBS. However, there is no clear national policy on NBS, but there is hope.
In 2015, Dr. S. Kamath, then-President of the Indian Academy of Pediatrics, a phased introduction of a three-category newborn screening program.
Category A (all newborns): Screening of all newborns for congenital hypothyroidism and hearing should be mandatory. Screening for CAH and G6PD deficiency should be done stepwise. G6PD screening should be done for all northern states in the country. Screening for sickle cell anemia and other hemoglobinopathies should be done in pockets with high incidence.
Category B (risk screening): In the high-risk population, screening should be done for the following conditions – consanguinity, children with unexplained intellectual disabilities, seizure disorders, previous unexplained sibling deaths, critically ill newborns, newborns/children with symptoms/signs/examinations suggestive of congenital metabolic disorders, etc. These conditions include phenylketonuria, homocystinuria, alkaptonuria, galactosemia, sickle cell anemia and other hemoglobinopathies, cystic fibrosis, biotinidase deficiency, maple syrup disease, medium-chain acyl-CoA dehydrogenase deficiency, tyrosinemia, and fatty acid oxidation defects.
Category C: Screening in resource-rich settings for 30-40 inherited metabolic disorders can be offered to ‘affluent’ families, particularly in urban settings where facilities for sending samples to laboratories are available.
WHO has recommended the introduction of newborn genetic services in countries with an infant mortality rate (IMR) of less than 50%. The author recommended that India, with an IMR of 40, implement newborn screening and genetic services immediately.