At present, only one gene (GPR56) is known to cause polymicrogyria, which leads to a distinctive phenotype termed bilateral frontoparietal polymicrogyria (BFPP).
We identified homozygous GPR56 mutations in 14 patients from eight consanguineous families with typical bilateral bifrontoparietal polymicrogyria and in one foetal case, out of 30 patients with bifrontoparietal polymicrogyria referred for molecular screening.
Functional studies of the GPR56 gene product will yield insights not only into the causes of polymicrogyria but also into the mechanisms of normal cortical development and the regional patterning of the cerebral cortex.
Human cerebral cortical polymicrogyria is a heterogeneous disorder, with only one known gene (GPR56) associated with an apparently distinctive phenotype, termed bilateral frontoparietal polymicrogyria (BFPP).