Search Results for: mosaicism Walsh

Mapping mosaicism: Tracing subtle mutations in our brains

DNA sequences were once thought to be the same in every cell, but the story is now known to be more complicated than that. The brain is a case in point: Mutations can arise at different times in brain development and affect only a percentage of neurons, forming a mosaic pattern. Now, thanks to new…

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Elusive epilepsy mutations begin to yield up their secrets

Anti-seizure drugs don’t work in about a third of people with epilepsy. But for people with focal epilepsy, whose seizures originate in a discrete area of the brain, surgery is sometimes an option. The diseased brain tissue that’s removed also offers a rare opportunity to discover epilepsy-related genes. Many mutations causing epilepsy have been discovered…

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Brain samples show a wealth of single-letter and somatic mutations in autism

Disease-causing mutations can be incredibly subtle: Sometimes a single-letter change in a gene or a so-called somatic mutation (affecting only some of the body’s cells) can be enough. Researchers report this week in Neuron that both kinds of mutations — easily missed on standard blood and saliva testing — play a role in autism spectrum…

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DNA diversity in the brain: Somatic mutations reveal a neuron’s history

Neurons are more like snowflakes–no two alike–than anyone realized. Walt Whitman’s famous line, “I am large, I contain multitudes,” has gained a new level of biological relevance in neuroscience. As we grow, our brain cells develop different genomes from one another, according to new research from Harvard Medical School and Boston Children’s Hospital. The study,…

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“Deep sequencing” finds hidden causes of brain disorders

It’s become clear that our DNA is far from identical from cell to cell and that disease-causing mutations can happen in some of our cells and not others, arising at some point after we’re conceived. These so-called somatic mutations—affecting just a percentage of cells—are subtle and easy to overlook, even with next-generation genomic sequencing. And…

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