SCIENTISTS SAY THEY believe they’ve found a gene responsible for brain size and development.

A group of researchers say they have identified that mutations in a single gene can determine the size of the brain, but also lead to severe defects. The findings are the result of two separate studies, carried out in labs across the world. You can check out the science behind them here and here.

Researchers studied the DNA of children born with the brain defect microcephaly, a condition in which the brain is abnormally small. They found that mutations in the gene NDE1 led to the abnormal development.

Aoife McLysaght (no relation), senior lecturer in Genetics at Trinity College explains that:

By comparing the DNA of the individuals with the condition against those who are unaffected the scientists searched for genetic differences that are shared by all those who were affected, but not found in unaffected individuals. They found disruptions of a particular gene called NDE1 in all of the affected individuals.

She says that a version of the NDE1 gene is also found in mice, but that scientists have found that where a mouse is deficient in this gene, they have a much less severe condition than humans deficient in the gene. Mc Lysaght says this indicates that the gene is important for some of the unique features of the human brain.

One of the scientists involved, Murat Gunel, says the discovery could have very practical applications, both in diagnosis and in understanding hw the brain develops.

Mc Lysaght agrees, telling TheJournal.ie:

We can’t do experiments on human brains to understand how they develop. Who would willingly submit to such a thing? What we can do though is examine cases where a naturally occurring disease affects brain development and try to understand what has gone wrong in these individuals. These two papers add to a growing list of genes found to be crucial for human brain development and which result in severe disease when disrupted.