Subhamoy Dastidar, Co-Founder and Director, Lilac Insights, talks about the burden of inborn errors of metabolism (IEM) in India and what lies ahead
Pregnancy is a transformative and joyful experience for almost all parents-to-be and their families. However, amid all the celebration, it’s important to be mindful of your 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 with a simple blood test. test at birth. Testing for such disorders at birth is called newborn screening or NBS.
IEM severity and other conditions
NBS is a process in which babies are screened immediately after birth for disorders that cause serious illness or death if not started in time. The following is a brief overview of the data available in India on various neonatal disorders.
- The incidence of IEMs is approximately 1:1000 in newborns. IEMs account for approximately 15 percent of total ICU admissions each year.
- Congenital hypothyroidism has a prevalence of 1 in 1,700 congenital hypothyroidism affects 1 in 2,575 and amino acid abnormalities predominate in 1 in 3,600 newborns.
- G6PD deficiency is the most common genetic disorder in India. Studies have shown between 2 and 27.9 percent in different communities.
- Approximately 4:1000 to 5:1000 newborns suffer from hearing defects and may have congenital heart defects.
- Galactosemia, caused by a deficiency of the enzyme galactose-1-phosphate-uridyltransferase, affects 4% of children with cholestasis of the newborn.
According to these data, more than several lakh children in India have metabolic genetic disorders. A recent study found that only 2 percent of NBS-detected cases had clinically severe outcomes compared with 42 percent of clinically detected cases. Delay in diagnosis of inborn error of metabolism or other diseases like hypothyroidism, G6PD deficiency etc. can lead to severe mental retardation, learning disabilities, autism, dyslexia, behavioral disorders, school retardation later in life. In severe cases, it can lead to sudden infant death syndrome (SIDS). Parents also have a significant financial and emotional burden of diagnosing, treating, and managing these disorders.
Therefore, timely and accurate diagnosis at the time of birth is necessary for prevention. Newborn screening is not only cost-effective, but also reduces parental stress, improving the quality of life for the child and family.
The viability and importance of NBS in the national health agenda
In developed and developing countries in the Asia-Pacific region, NBS programs have been successfully implemented for quite a number of metabolic genetic disorders over the past few decades.
In 2008, ICMR launched an NBS program to screen 100,000 newborns for CH and CHG in 5 metropolitan cities of Chennai, Delhi, Hyderabad, Kolkata and Mumbai. In 2011, a national neonatology forum recommended CH, CAH and G6PD screening for all newborns in India.
Many small pilot projects have been launched in the past. Among them Chandigarh Programme, Kerala NBS Program and Goa NBS Program have done some commendable work. In 2007, Chandigarh started 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, which are yet to be implemented.
India also lacks a recognized champion to advocate for NBS to become a universal preference in India.
Current status and future of the universal NBS program
Community studies recommend that universal screening programs include two to four diseases. Currently, private NBS programs have taken the lead with packages to detect three diseases in a comprehensive set (for 50+). Since 52 percent of births in India take place in public hospitals, public NBS screening programs have the potential to achieve universal screening.
With a few limited screening programs, there is now more awareness of the benefits of NBS. However, there is no clear national policy regarding NBS, but there is hope.
In 2015, Dr. S. Kamat, then president of the Indian Academy of Paediatrics, recommended a three-category newborn screening program in a phased manner.
Category A (all newborns): All newborns should be screened for congenital hypothyroidism and hearing. Screening for CAH and G6PD deficiency should be performed in stages. G6PD screening should be done for all northern states of the country. Screening for sickle cell disease and other hemoglobinopathies should be done in pockets with high rates of disease.
Category B (High Risk Screening): The following disorders should be screened in high-risk groups: blood relatives, children with unexplained intellectual disability, seizure disorder, previous unexplained death of siblings, critically ill neonates, neonates/children with symptoms/signs/tests suggestive of inborn errors of metabolism These diseases include phenylketonuria, homocystinuria, alkaptonuria, galactosemia, sickle cell anemia and other hemoglobinopathies, cystic fibrosis, biotinidase deficiency, maple syrup urine disease, medium-chain acyl-CoA dehydrogenase deficiency, tyrosinemia, and fatty acid oxidation defects.
Category C: In resource-rich families, screening for 30 to 40 inherited metabolic disorders can be offered, especially in urban areas that have the means to send samples to a laboratory.
WHO recommended that newborn genetic services be introduced in countries with an infant mortality rate (IMR) of less than 50. The author recommended that India with an IMR of 40 immediately introduce newborn screening and genetic services.