Subhamoy Dastidar, Co-Founder & Director, Lilac Insights talks about the burden of Inborn Errors of Metabolism (IEMs) in India and way ahead for the same
Pregnancy is a transformative and joyous experience for almost all expecting parents and their families. However, amidst all the celebration, it is important to be cognizant of a baby’s health, especially when it comes to detecting irreversible disorders such as Congenital Hypothyroidism, G6PD, Inborn Errors of Metabolism or IEM, that can be diagnosed and prevented through a simple blood test at birth. The testing of such disorders at birth is called Newborn Screening or NBS.
The burden of IEMs and other conditions
NBS is the process by which babies are screened just after birth for disorders that cause severe illnesses or death unless treated early. Below is a glimpse into the data available in India for the various disorders that are detected in newborns.
- The incidence of IEMs is approximately 1:1000 in newborns. IEMs comprise approximately 15 per cent of total admissions in NICUs annually.
- There is a prevalence of congenital hypothyroidism with 1 in 1700 suffering congenital adrenal hypothyroidism affecting 1 in 2575, and amino acid disorders prevail in 1 in 3600 newborns.
- G6PD deficiency is the most common genetic disorder in India. Studies have reported 2 per cent to 27.9 per cent in different communities.
- Approximately 4:1000 and 5:1000 newborns suffer from hearing defects and may have congenital heart abnormalities.
- Galactosemia, caused by the deficiency of the enzyme Galactose-1-phosphate uridyl transferase, affects 4 per cent of children with neonatal cholestasis syndrome.
According to this data, over a few lakh children have metabolic genetic disorders in India. A recent study showed that only 2 per cent of cases detected by NBS had clinically severe outcomes compared to 42 per cent of those detected clinically. The delay in diagnosis of an Inborn Error of Metabolism or other conditions like hypothyroidism, G6PD deficiency, etc. can lead to severe mental retardation, learning disabilities, autism, dyslexia, behavioural abnormalities, scholastic backwardness later in life. In severe cases, it may lead to Sudden Infant Death Syndrome (SIDS). There is also a considerable financial and emotional burden on parents to diagnose, treat, and manage these disorders.
Therefore, a 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 baby and the family.
Viability and importance of NBS in National Health Programme
Past efforts
In developed and developing countries in the Asia Pacific region, NBS programmes for quite a few metabolic genetic disorders have been successfully implemented over the last few decades.
In 2008, ICMR launched an NBS program to screen 100,000 newborns for CH and CAH in the 5 metropolitan cities 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-scale pilot projects have taken off in the past. Among these, the Chandigarh Program, Kerala State NBS program, and Goa NBS Programme have done some commendable work. In 2007, Chandigarh started NBS for CAH, CH and G6PD. In 2008, Goa introduced mandatory expanded NBS for all newborns. In 2009 West Bengal and in 2011 Gujarat approved the launch of large-scale NBS programmes, which are yet to be implemented.
India has also lacked a recognised champion, advocating for NBS to make it a universal benefit in India.
Current state and future of universal NBS programme
Public studies recommend that universal screening programmes should include two to four disorders. Presently, private NBS programmes have taken the lead with packages to detect three disorders to a comprehensive set (for 50+). Since 52 per cent of births in India are in public hospitals, public NBS screening programmes have the potential to achieve universal screening.
With a few limited screening programmes, there is now more awareness of the benefits of NBS. However, there is no clear national policy on NBS, but there is hope.
In 2015, Dr S Kamath, the then president of the Indian Academy of Pediatrics, recommended a phased introduction of a newborn screening programme with three categories.
Category A (all newborns): Screening in all newborns for congenital hypothyroidism and hearing should be carried out on a mandatory basis. Screening for CAH and G6PD deficiency should be conducted in a phased manner. G6PD screening should be done for all Northern states of the country. Screening for Sickle Cell disease and other hemoglobinopathies should be undertaken in pockets where there is a high incidence.
Category B (High-risk screening): Screening for the following disorders should be conducted in the high-risk population –consanguinity, children with unexplained intellectual disability, seizure disorder, previous unexplained sibling deaths, critically ill neonates, newborns/children with symptoms/ signs/investigations suggestive of inborn errors of metabolism etc. These conditions include phenylketonuria, homocystinuria, alkaptonuria, galactosemia, sickle cell anaemia, 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: Screening in resource-rich settings for 30-40 inherited metabolic disorders may be offered to ‘well-to-do’ families, especially in urban settings where facilities for sending samples to laboratories are available.
The WHO has recommended that genetic services for newborns should be introduced in countries with an Infant Mortality Rate (IMR) of less than 50. The author recommended that India with an IMR of 40 should introduce newborn screening and genetic services immediately.