When a heel prick tells you if your newborn has an incurable disease

Emily Baumgaertner Nunn

In every postpartum hospital unit across the US, one-day-old babies undergo the same ritual: A nurse pricks the newborn’s heel and stamps tiny drops of blood onto a paper filter, which is then sent off for a standard screening panel.

Today, that panel checks for unusual biomarkers that may indicate a rare but treatable disease like sickle cell anaemia or cystic fibrosis. But what if that same dried blood spot could tell you about the baby’s risk of developing certain conditions later in life — some with no method of prevention or cure? What if that heel prick could tell you that the baby was almost certainly going to be diagnosed with autism by the time they turned 5? Or that the child would be more likely to develop breast cancer as an adult?

Would you want to know?

Tens of thousands of parents have sought such insights by enrolling their newborns in research projects that examine the baby’s genome — the full blueprint for her growing body. As the cost of sequencing plummets, the practice of analysing hundreds of genes in healthy babies is quietly on the rise, ushering in new questions about where to draw the boundaries of knowledge — and who should get to decide.

The possibilities are almost endless, since virtually every disease has some basis in our genes. The full genome has a wealth of data to be mined for lifesaving intel and gut-wrenching secrets. But some experts say revealing risk of an incurable illness will only give parents despairing predictions for their child’s life. Some believe data about diseases that arise in adulthood, like breast or colon cancer, must be excluded, since they violate the future adult’s right not to know. Still others feel genetic forecasting is the future of medicine — if used wisely.

Should we prick, probe?

By the 1960s, the WHO had published a list of 10 principles to guide whether a condition was apt for population-based screening, stating there should be a consensus about a positive case and available treatment. But there’s no such oversight system for whole genome sequencing, now available to anyone with curiosity and money. In some hospitals where research is underway, parents are even paid to participate.

Most experts agree that if examining a gene can reliably prevent a devastating outcome, we should do it. An infant born with mutations in both copies of the SMN1 gene, for example, will develop Type 1 spinal muscular atrophy (SMA) — in which nerve cells in the spinal cord waste away, killing the child by age 2. But if the baby is given a therapy starting at 15 days old, she can meet all developmental milestones and stave off symptoms indefinitely.

Maximise Child’s Outcome

Parents might learn about a mutation days after their child’s birth, but it could take months, years, even decades to see what bearing that has on the child’s life. But many leading researchers are not intimidated by this uncertainty, or worried about a condition being curable, so long as it can be acted upon in some way. A study by paediatric clinical and molecular geneticist Dr Wendy Chung offers sequencing results for about 450 conditions to parents of babies born in New York-Presbyterian hospitals. More than 90% of enrolling parents have opted into results from a panel of conditions that have no cures, including ones linked to autism. The rationale is that the data could grant a child access to speech and occupational therapy while the brain is still plastic, enabling earlier treatment for accompanying conditions such as epilepsy, GI issues, and vision and hearing problems.

“Parents understood that it’s there, regardless of whether you read it out. They told us: if it’s going to be what it’s going to be, I’d rather feel empowered to potentially maximise my child’s outcome,” Dr Chung said. NYT News Service

Newborn screening picks up pace in India

India has no national newborn screening programme though some states like Kerala offer free tests for about three to six genetic disorders. However, both public and private hospitals in India conduct paid tests that typically include pulse oximetry to detect congenital heart defects, hearing tests for congenital hearing loss, and heel prick blood tests to screen for a range of metabolic and hormonal disorders. In recent years, several private laboratories have begun offering advanced genetic screening panels, including expanded panels that use Next-Generation Sequencing (NGS).

These tests are performed on blood collected via a heel prick within 48 to 72 hours of birth, which is then dried on a special filter paper known as a Guthrie card. In addition to common genetic disorders such as Thalassemia, Spinal Muscular Atrophy (SMA) and Pompe Disease, these tests can detect a wide range of other rare conditions. Costs for these screenings typically range between Rs 5,000 and Rs 25,000. However, not everyone is advised screening, says Dr Jayashree Mondkar, senior neonatologist and ex-dean of BMC-run Sion Hospital, Mumbai. “For rare disorders like SMA or Gaucher’s disease — where treatment is expensive and time-sensitive — early genetic diagnosis can guide critical medical decisions, enable preventive care, and reduce financial and emotional burden on families. But we usually advise genetic testing only in high-risk cases,” shesays.

Reporting by Lata Mishra