Blood oxygen levels drop during sleep, but how much and when that happens is mainly hereditary? Now researchers from Brigham and Women’s Hospital and Case Western Reserve University are getting closer to finding the genetic reasons for the fluctuations, which could help people with sleep apnea and other lung illnesses.
In their study, funded by the National Heart, Lung, and Blood Institute (NHLBI), the researchers analyzed whole genome sequence data from the NHLBI’s Trans-Omics for Precision Medicine (TOPMed) program. They also incorporated results for family-based linkage analysis, which maps genes with hereditary traits to their location in the genome.
The researchers identified 57 genetic variations of DLC1, a gene consistently associated with average arterial oxyhemoglobin saturation during sleep. The variants explain almost 1% of the variability in the oxygen levels in European Americans. That is high for complex genetic phenotypes, the researchers say. Of the 57 variants, 51 influence and regulate human lung fibroblast cells.
“This study highlights the advantage of using family data in searching for rare variants,” says James Kiley, PhD, director of the Division of Lung Diseases at NHLBI. “It showed that, when guided by family linkage data, whole genome sequence analysis can identify rare variants that signal disease risks, even with a small sample. In this case, the initial discovery was done with fewer than 500 samples.”