Breaking News
admin
Apr 22 2025
2A new study led by researchers at Vanderbilt University Medical Center (VUMC) has mapped the evolution of clinical genetic testing over the past two decades, revealing a marked increase in testing rates, diagnostic outcomes, and testing complexity. The research, published in the American Journal of Human Genetics, analyzed electronic health record (EHR) data from more than 1.8 million individuals seen at VUMC between 2002 and 2022.
The study identified 104,392 genetic tests performed for 77,033 individuals. Of these, nearly 86% were conducted for diagnostic purposes, while 9.6% were associated with carrier screening and 4.4% with familial variant testing. Over the 20-year span, the use of clinical genetic testing grew significantly, accompanied by a corresponding increase in diagnoses and in the detection of variants of uncertain significance.
Lead author Lisa Bastarache, a researcher in biomedical informatics and digital genomic medicine at VUMC, emphasized the broader reach of genetic testing today. “Twenty years ago, genetic testing was highly specialized, often reserved for individuals with severe, life-limiting conditions like cystic fibrosis,” Bastarache noted. “Now, testing spans virtually all areas of medicine.”
The data showed that by 2022, clinical genetic test results were present in over 6% of EHRs—up from just 1% in 2002. Testing was especially prevalent among patients referred to specialists, with one in eight specialist patients undergoing genetic testing.
The study also documented a substantial increase in genetic diagnoses: 19,032 cases were diagnosed through testing, including 533 individuals who received multiple diagnoses. The tests identified genetic risk variants in 18,476 individuals, spanning over 7,500 different conditions—from more common disorders like Down syndrome and Huntington disease to ultra-rare conditions observed in only a single patient. In comparison, only 51 conditions were diagnosed with genetic testing in 2002, a number that grew to 509 by 2022.
Over time, the nature of testing shifted from single-gene assessments to broader, more inclusive multi-gene panel tests. More than a quarter of the tests in the study used multi-gene panel sequencing. Single-gene and single-variant tests accounted for 23.1% and 17.3%, respectively. Chromosomal microarrays were used in 14.1% of cases, karyotype tests in 9.7%, and repeat-expansion tests in 7.1%. A small proportion of tests used more advanced methods, such as exome or whole-genome sequencing (1.3%) and methylation testing (1.1%).
The team also employed phenome-wide analysis to calculate the "genetically attributable fraction" (GAF) for various clinical conditions, identifying 74 phenotypes where at least 5% of cases could be linked to genetic variants.
Despite the growth in testing, researchers highlighted ongoing challenges in how genetic data are recorded. Much of the test information remains embedded in non-machine-readable PDFs, limiting its accessibility for broader analysis. Bastarache argued that structuring this data in a computable format could significantly improve health system understanding and guide better testing practices.
The team is now working on developing automated methods to extract genetic data from EHRs, which could enhance rare disease diagnosis and clarify genotype-phenotype relationships. They are particularly focused on conditions like cystic fibrosis, Marfan syndrome, and sickle cell anemia.
“Clinical genetic testing and diagnoses are accelerating across healthcare,” Bastarache concluded. “We’re at the start of a new research era that explores rare diseases on a population level, ultimately improving patient diagnosis and care.”
Source:https://www.genomeweb.com/genetic-research/vanderbilt-team-reports-clinical-genetic-testing-patterns-over-two-decades
This is non-financial/medical advice and made using AI so could be wrong.
