A 1-in-27,000 Finding: Newborn Blood Spots Could Reveal Childhood Cancer Risk

A 1-in-27,000 Finding from Michigan's Archived Blood Spots

Researchers have shown that a targeted genomic test on newborn dried blood spots can identify children who carry inherited cancer-risk variants. In a study of 1,948 Michigan children born between 1987 and 2020 who later developed a solid or central nervous system tumour by age 8, sequencing of 11 cancer predisposition genes detected pathogenic or likely pathogenic variants in 132 children, or 6.8%.

The team, led by Lisa Diller of Dana-Farber Cancer Institute and colleagues, estimates the approach would identify about 1 in 27,000 infants who will develop cancer by age 8 because of a genetic predisposition syndrome. That rate is broadly comparable to some conditions already included in newborn screening: it is less common than Pompe disease at about 1 in 18,000 births, but more common than severe combined immunodeficiency at about 1 in 59,000 births and maple syrup urine disease at about 1 in 200,000 births.

The strongest results came from genes with already known cancer links. All six children in the study who developed medullary thyroid carcinoma had a RET variant, and 40% of children with retinoblastoma carried an RB1 variant. The authors argue that finding these variants at birth could allow surveillance, such as regular eye exams for RB1 carriers or kidney ultrasounds for Wilms tumour risk, so tumours are caught when treatment may be less intensive.

What the 11-Gene Panel Means for Newborn Screening

Why RB1 and RET make the screening case

The panel focused on autosomal dominant cancer-risk genes where early detection opens a practical surveillance pathway. Diller points to retinoblastoma: a clinically detected tumour often requires chemotherapy, surgery or radiation and can cost sight, while a newborn identified as an RB1 carrier can have frequent eye exams and, if a tumour appears, be treated with laser or cryotherapy. For Wilms tumour risk, knowing a child's status can trigger ultrasound every three months, potentially avoiding kidney loss and minimising chemotherapy. That distinction between identifying a variant and changing the clinical course is central to the researchers' argument.

Why Parad says the infrastructure is already in place

Co-author Richard Parad argues that many pieces already exist. State newborn screening programs collect dried blood spots and public health laboratories already extract DNA from those samples to screen for severe combined immunodeficiency. A targeted 11-gene panel is cheaper than whole-genome sequencing, and the sequencing machine cost is comparable to a tandem mass spectrometer that labs already buy, according to Parad. The remaining challenge is interpretation: software is becoming more automated, but deciding which variants deserve follow-up remains more difficult than running the sequencer.

What the evidence does not yet prove

The findings come from children who already developed cancer, not from a prospective universal screening program. The authors themselves note uncertainties about psychological distress, surveillance burden in young children, and the possibility of overdiagnosis or unnecessary interventions from indeterminate findings. A companion parent survey published in the Journal of Pediatrics found families described a cancer predisposition diagnosis as emotionally challenging, yet considered the process worthwhile and supported offering newborn screening. That support is encouraging, but it comes from families who had already lived through the diagnosis rather than from a representative sample of all parents being screened.

Next Steps for State Screening Programs and Families

• State newborn screening advisory bodies can weigh the 1-in-27,000 estimate against existing screened conditions: it is more common than severe combined immunodeficiency and maple syrup urine disease, but less common than Pompe disease.
• Public health laboratories testing feasibility can start with the 11-gene targeted panel rather than whole-genome sequencing; the study notes DNA is already extracted for SCID screening and sequencing equipment is comparable in cost to tandem mass spectrometers already in use.
• Pediatric oncology teams may use the gene-specific patterns, such as RET in all six medullary thyroid carcinoma cases and RB1 in 40% of retinoblastoma cases, to support early genetic evaluation for children diagnosed with those tumours, while recognising that universal screening protocols are not yet established.
• Families with a known history of retinoblastoma, Wilms tumour or other conditions covered by the 11-gene panel should understand that these genes are not currently part of routine newborn screening; the study is research evidence for future policy, not an existing service.