In PLOS Medicine, researchers from the UK, South Africa, Australia, and elsewhere report on blood gene expression profiles for detecting active tuberculosis infections, even in individuals infected with HIV. The group tracked down 27-transcript and 44-transcript signatures that differ between active and latent TB infection and between active TB infection and other diseases, respectively, using samples from hundreds of HIV-negative and -positive patients from Malawi or South Africa. By combining these signatures into a disease risk score, the investigators demonstrated that they could accurately detect TB in follow-up stages of the study, both in those with or without HIV infection. Our sister publication GenomeWeb Daily News has more on the study, here.
Ohio State University periodontology researcher Purnima Kumar and colleagues used deep sequencing to identify members of microbial communities that tend to turn up in the mouths of individuals from different ethnic backgrounds — work they describe in PLOS One. The team performed 16S ribosomal RNA sequencing on spit and dental plaque samples from 192 American individuals of African, Latino, Caucasian, or Chinese descent, defining core mouth microbes in the study participants. Those microbiomes tended to cluster with individual's ethnicity, study authors say, making it possible to pick up on mouth microbial signatures for predicting ethnicity.
Genetic factors that dial up the likelihood of developing Tourette syndrome are largely distinct from those involved in obsessive-compulsive disorder risk, according to a PLOS Genetics study. A large team of investigators from around the world brought together array-based genotyping data for thousands of individuals with Tourette syndrome, OCD, and unaffected controls as part of a genome-wide complex trait analysis. This analysis unearthed differences in the genetic architecture behind the neuropsychiatric conditions — indicating, for example, that rare variants make a more pronounced contribution to Tourette syndrome than to OCD. Overall, study authors conclude, the results reveal that "there is some genetic overlap between these phenotypically related neuropsychiatric disorders, but suggest that the two disorders have distinct genetic architectures."