In this week's Nature Genetics, a team led by scientists from DeCode Genetics reports the results of a genome-wide association study of people who underwent total hip replacements, identifying rare genotypes associated with the risk of hip osteoarthritis. Through the study — which included 4,657 Icelandic patients and more than 200,000 population controls — the researchers discovered two rare signals that strongly associate with osteoarthritis total hip replacement, including a rare missense variant in the gene COMP and a recessive frameshift mutation in the gene CHADL. While the COMP variant is specific to the Icelandic population, the frameshift variant in CHADL is "widespread in populations of European and Middle Eastern descent and is found at lower frequency in East Asians, suggesting that the mutation occurred a long time ago," the authors note.
And in Nature Methods, Albert Einstein College of Medicine investigators describe a new method for the accurate identification of single-nucleotide variants in whole-genome-amplified single cells. The approach involves a procedure called single-cell multiple displacement amplification, or SCMDA, and a general-purpose single-cell-variant caller dubbed SCcaller. By comparing SCMDA-amplified single cells with unamplified clones from the same population, the scientists were able to validate their procedure as "a firm foundation for standardized somatic-mutation analysis in single-cell genomics."