Using genome and exome sequencing as early diagnostic tools, according to Christine Eng, MD

Christine Eng, MD, Professor of Genetics at Baylor College of Medicine and chief medical officer and chief quality officer at Baylor Genetics, discussed how earlier use of genome testing can affect the diagnostic process for children with suspected genetic conditions.

Eng noted that updated guidance has contributed to earlier utilization of genome sequencing. “So we're already seeing how these guidelines can make a real difference for families,” she said. Eng explained that historically, families often “spent years going through multiple rounds of targeted testing before reaching a diagnosis,” which prolonged uncertainty and absorbed clinical time during attempts to determine a cause.

According to Eng, earlier exome or genome sequencing allows clinicians to move more efficiently from diagnosis to management. “Once a diagnosis is made, then you can move past that stage and into the stage of medical management and proactive management,” she said. She emphasized that using sequencing as “a first step, not a last resort” can help identify underlying causes more quickly and support timely, individualized medical care.

Multi-omic approaches may expand diagnostic capabilities

Eng described a shift toward integrating additional “omic” technologies with genomic data. “We feel that the future of genomics and precision diagnostics is really multi-omic,” she said. She defined this as including “other types of omic technologies such as transcriptomics, that's the study of RNA metabolomics, which is a biochemical assay,” along with emerging tools such as optical genome mapping and long-read sequencing.

She noted that “AI-driven variant interpretation is helping uncover conditions that were previously more difficult to diagnose,” potentially enabling earlier and more actionable clinical insights.

Rapid and ultra-rapid sequencing may support urgent clinical decisions

Eng highlighted the use of rapid sequencing in acute care. “Currently, we have a 5-day turnaround time for rapid WGS, which we find very helpful in intensive care settings, to give clinicians answers as soon as possible,” she said. Advances may soon accelerate this further: “We are moving towards an ultra-rapid sequencing, which can perhaps approach two to three days or even less.”

Equity and access remain central challenges

Despite technological advances, Eng emphasized persistent disparities. “It still remains that equity and access are a critical focus,” she said, pointing to gaps in referrals, insurance coverage, and access to genetic counseling.

She added that population-level genomic data may support broader improvements. “Analyzing genomic data across communities will help identify trends, better understand rare conditions, and improve care for specific groups of children, not just individual patients,” she said. These data may also “support justification to payers about why these tests should be covered for children that need them.”

Disclosure: Eng is the chief medical officer of Baylor Genetics.

Reference:

Rodan LH, Stoler J, Chen E, et al. Genetic Evaluation of the Child With Intellectual Disability or Global Developmental Delay: Clinical Report. Pediatrics. Published online June 23, 2025. doi:https://doi.org/10.1542/peds.2025-072219