Genomics for human health

New syndrome causing intellectual disability and susceptibility to obesity identified

Scientists at the University of Manchester, in collaboration with qGenomics and other research groups, have discovered a rare new genetic syndrome associated with neurodevelopmental disorders, susceptibility to obesity and over-eating, in six families, from across the world. 
Dr Siddharth Banka, Clinical Senior Lecturer at the Manchester Centre for Genomic Medicine, who led the study, explained: "Our team has identified that this new syndrome is caused by a small deletion on chromosome 6 that alters the dose of an essential gene for the correct development and function of hypothalamus, a region of the brain that plays a number of important roles in the body." 
Working in collaboration with Dr Eric Glasgow of the Georgetown University Medical Center in Washington D.C., the two teams used zebrafish models to study the consequences of the deletion of this gene located at chromosome 6 and showed that its suppression has an effect on specific cells in the hypothalamus that produce a hormone called oxytocin. 
This could help to explain why patients harbouring only one copy of this gene are often severely obese, with difficulties to control their appetites and are prone to mood swings and being withdrawn, the researchers say. The study, published in a recent issue of the American Journal of Human Genetics, represents an important step in the understanding of this molecular pathway related to hypothalamic function, conserved across species, emphasizing its biological importance, according the researchers.
"This finding demonstrates the power of genetic study of rare conditions, that in this case has contributed to identify the critical region associated with a distinctive phenotype. In addition helping to delineate the neuro-endocrine control of food intake explain Olaya Villa and Cristina Hernando, researchers at qGenomics and participants in the study.

Paul R. Kasher et al. Small 6q16.1 Deletions Encompassing POU3F2 Cause Susceptibility to Obesity and Variable Developmental Delay with Intellectual Disability, The American Journal of Human Genetics (2016). DOI: 10.1016/j.ajhg.2015.12.014