One neuron may have over 1,000 mutations

New York: A single neuron in a normal adult brain may carry more than a thousand genetic mutations most of which may be harmless, new research has found.

The majority of these mutations appear to arise while genes are in active use, after brain development is complete, found the study by Maryland-based Howard Hughes Medical Institute (HHMI) scientists.

"We found that the genes that the brain uses most of all are the genes that are most fragile and most likely to be mutated," said lead research Christopher Walsh, HHMI investigator at Boston Children's Hospital.

For the study, the scientists isolated and sequenced the genomes of 36 neurons from healthy brains donated by three adults after their deaths.

For comparison, the scientists also sequenced DNA that they isolated from cells in each individual's heart. What they found was that every neuron's genome was unique.

Each had more than 1,000 point mutations - mutations that alter a single letter of the genetic code. What is more, the nature of the variation was not quite what the scientists had expected.