In PLOS Neglected Tropical Diseases, investigators from the H3Africa Consortium's TrypanoGEN Research Group describe an apolipoprotein-L1 (APOL1) gene variant that may protect against human African trypanosomiasis (HAT)-causing Trypanosoma brucei rhodesiense infections. The team narrowed in on the proposed protective allele, known as G2, by genotyping markers in 17 suspicious genes in 70 HAT cases and 132 unaffected, T. b. rhodesiense-exposed controls from the same part of northern Malawi — a country where chronic symptoms have been documented more often than in other HAT-affected parts of eastern and southern Africa. Just one of the 96 variants — G2 in APOL1 — had significant associations with HAT, the authors note, suggesting that similar studies documenting disease progression differences in specific populations "could offer opportunities for development of much needed new diagnostics and intervention strategies."
A University of Copenhagen-led team takes a look at a potential type 2 diabetes role for the GLIS3, a gene believed to function in the pancreas' insulin-producing beta-cells that contains common variants implicated in T2D by genome-wide association studies. As they report in PLOS One, the researchers did targeted GLIS3 sequencing in 2,930 newly diagnosed T2D cases; 206 forms of diabetes with autoimmune markers related to type 1 diabetes; 53 individuals with a rare form of diabetes called maturity onset diabetes of the young (MODY); and more than 5,700 unaffected control individuals. Although the rare, missense variants they identified did not seem to have a causal role in MODY, the authors did see an increase in the rare, missense GLIS3 variants in individuals with T2D and other specific diabetes features, along with a potentially protective variant in the gene with ties to lower-than-usual fasting plasma glucose levels.
A team from Norway, the US, and Mongolia document brown bear diversity, relationships, and phylogeographic patterns in Central Asia for another PLOS One paper. Along with almost 2,400 brown bear samples collected in the Gobi Desert, the researchers considered dozens of samples from mountainous regions in Mongolia and Pakistan, comparing genotypes across more than a dozen nuclear DNA microsatellite regions and a stretch of informative mitochondrial DNA sequence. Their results suggest that the genetic diversity of brown bear populations from northern Mongolia outpaces that of brown bears in Pakistan's Himalaya region or in the Gobi Desert, for example. The analyses also helped to place the lineages found in Central Asia within a broader brown bear tree, while highlighting distinct population structures and subpopulations in the Gobi bears.