Singapore (ISJ) ? A team led by an Indian scientist has discovered the hidden genetic causes of brain disorders. The study led by Dr. Saumya Jamuar, a researcher at Harvard Medical School and Boston Children?s Hospital and Prof. Christopher Walsh, Chief of Genetics and Genomics at Boston Children?s Hospital have discovered genetic causes of neurologic and psychiatric conditions using a technique called ?targeted high-coverage sequencing?. Both Jamuar and Walsh are co-founders of Global Gene Corp in Singapore.
The study found mutations in 158 patients with brain malformations of unknown genetic cause, who had symptoms like seizures, intellectual disability and speech and language impairments. Instead of analysing the whole genome or exome (protein-coding regions of genes), the scientists focussed on a panel of known or suspected genes.
?This new approach enhances whole-genome and whole-exome sequencing. We found that that 30% of patients with an identified mutation had a somatic mutation, 60% of which would have been missed on traditional testing. This has huge implications for researchers studying similar disease conditions such as autism, schizophrenia, etc. It changes the way we think about genetic diseases and lastly, translates into clinically relevant diagnostic tool that can help reach a patient?s diagnosis. With increasing diagnosis and awareness of these mutations, the hope is that it would lead to identification of a potential target for medication and cure,? said Dr. Jamuar, commenting on the study.
Traditionally, it is known that genes are inherited from parents and each cell of our body has the same genetic make-up. Variations in our genes, also known as mutations, disrupt the function of the gene, which can lead to a disease. These mutations can be inherited from parents or can arise spontaneously when the egg or the sperm is being formed ? known as novo mutations. In these cases, all cells of the body will carry the mutation.
More recently, however, researchers have realised, an individual can have two or more different genetic make-up ? one normal and other abnormal, a process known as somatic mosaicism. In this scenario, the mutation develops after fertilisation (when the sperm and egg have come together to form the embryo) and hence, only affects some cells. It is established, each one of us carries at least one such mutation in our body but the relevance of somatic mosaicism to human disease has not been documented.
