Primary microcephaly is caused by changes in certain genes, most commonly the WDR62, ASPM, MCPH1and CEP135genes. These genes help control how brain cells grow and divide during early development.
When there's a mistake in the gene, the brain doesn’t grow properly before birth, especially the outer part of the brain, which is important for thinking and learning.
The condition is usually inherited in an autosomal recessive way, meaning both parents carry a non-working copy of the gene, but they don’t have symptoms themselves. The child gets both non-working copies and develops the condition.
CEP135