SciLifeLab The Svedberg seminar series 2014-01-13
Johanna C. Andersson-Assarsson
Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden
Johanna got a masters degree in chemistry (biomedical chemistry) at the Linnaeus University in Kalmar in 1997 and a PhD in pathology at University of Gothenburg in 2005. During her PhD she focused on tumor biology, in particular the role of gene mutations in tumor progression and treatment. After her PhD, she changed fields to genetics of obesity as a Wellcome Trust-funded postdoctoral fellow in the world-renowned laboratory of Professor Philippe Froguel at the Department of Genomics of Common Disease at Imperial College London. Since 2011, she holds an assistant professor position at the Wallenberg Laboratory at Department of Molecular and Clinical Medicine in Gothenburg and her research focus is genetics of obesity and related disease.
Prevalence and effects of the obesity associated deletion on chromosome 16p11.2 in the Swedish Obese Subjects (SOS) study.
The overall aim of my research is to identify and evaluate genetic alterations, primarily copy number variants (CNV), in obesity and related diseases. Common obesity results from a combination of environmental and genetic factors. Studies have shown a very high heritability, up to 70%, for many obesity-related traits. Much effort has been made to identify candidate gene variants in common obesity, with some notable successes such as the discovery of the FTO variants. However, the majority of the heritability remains to be explained.
Copy number variants (CNV) may explain part of this “missing heritability”. They are an important source of genetic variability between individuals and have been associated with normal phenotypic diversity as well as with common diseases, including obesity. We and others have previously identified a rare CNV (a deletion) on chromosome 16p11.2 that give rise to a highly penetrant form of obesity.
My current research focus is on this further evaluation of this deletion in the SibPair Study (SibPair) and the Swedish Obese Subjects (SOS) study. SibPair is a family cohort of 732 individuals from 154 nuclear families ascertained via an extremely BMI-discordant sib pair (at least 10 units). The SOS study started in 1987 and is a prospective, controlled, intervention study involving 4047 obese individuals; 2010 individuals have undergone bariatric surgery and 2037 conventional treatment (matched control group).
We have identified 16 carriers of the deletion in these cohorts and are continuing our investigation in two different projects: 1) evaluation of the effects of the chromosome 16 deletion on anthropometry, metabolism, obesity-related disease and outcome after bariatric surgery, and 2) deep characterization of the region to be able to pinpoint causative gene/genes. Results from preliminary analysis include differences in anthropometric measurements and a good response to bariatric surgery.
Host: Dan Larhammar