A team from Denmark, Germany, and the US describes a derived common variant that appears to track with lower body mass index (BMI) and advantageous metabolic features in Arctic populations. From the first stage of a BMI-focused genome-wide association study involving 4,626 individuals from Greenland, the researchers focused in on a derived, intergenic variant on chromosome 11 called rs4936356, which remained tied to decreased BMI after replication and meta-analyses with almost 1,100 Native Alaskan Yup'ik individuals and more than 1,500 Greenlanders. The follow-up analyses suggested that the variant "was associated with lower body mass index, lower insulin resistance, and favorable lipid levels," they report, though they caution that "further studies are required to replicate these findings and to identify the gene through which the rs4936356 variant is affecting body mass index."
Researchers from Italy and Sweden search for blood microRNA markers coinciding with a range of traits or conditions in individuals classified as "born small for gestational age," or SGA. For that prospective PLOS One study, the team collected blood samples from 23 SGA individuals at 9 years old and again when they turned 21, comparing their circulating miRNA profiles with those present in 27 age-matched, "appropriate gestational age" control individuals. While the authors did not see miRNAs or metabolites that consistently tracked with SGA status, they did detect miRNAs with age-related shifts, along with a miRNA that had apparent ties to insulin sensitivity or resistance in the SGA individuals. "[O]ur data do not support the speculation that SGA subjects have a different/peculiar profile of circulating miRNAs related to cardiometabolic risk," the authors explain, noting that early biomarkers for future metabolic or cardiovascular conditions will need to be examined in larger and more complete prospective studies.
For another paper in PLOS One, a team from Brazil and Portugal takes at the sarcoma risk associated with a Li-Fraumeni Syndrome-related TP53 germline variant that's found at higher-than-usual frequency in Brazil. Using a combination of PCR, restriction fragment length polymorphism profiling, and confirmatory Sanger sequencing, the researchers assessed matched tumor and normal blood samples from more than 500 unselected Brazilian individuals with sarcoma, uncovering the risky Brazilian version of TP53 in 8 percent of those patients. More than half of sarcoma cases found in individuals with the TP53 germline variant were histologically classified as leiomyosarcomas, the authors report, noting that the current results "emphasize the importance of genetic counseling and can better guide the management of sarcoma patients."