There are people walking about with genetic variants associated with conditions like heart disease, cancer, and autism, but who are healthy, Spectrum reports. Such people may be at later risk of developing disease or, for some conditions, have a mild case that could inform research into the continuum of symptoms.
A study published in December of last year in Science found that 3.5 percent of 50,726 human genomes analyzed had variants within 76 genes linked to disease, including 56 on American College of Medical Genetics and Genomics' list of clinically actionable genes, as GenomeWeb reported at the time. But, as Spectrum notes, about a third of those people with disease-linked variants had no symptoms or family history of that disease. For instance, it adds that a companion study in Science found that most of the people who harbored a variant associated with high cholesterol had normal levels of cholesterol. Spectrum additionally points out that some 2,000 people in the MyCode cohort have variants linked to autism, intellectual disability, or schizophrenia, but that fewer than 5 percent had been treated for those conditions.
This suggests that people may harbor other, protective variants or might have subtle versions of such conditions, Spectrum adds. "This cohort could help us describe the full picture of autism, the breadth of the phenotype," Christa Lese Martin, director of the Autism and Developmental Medicine Institute at Geisinger Health System, tells Spectrum.