A focal epilepsy and intellectual disability syndrome is due to a mutation in TBC1D24

A multipoint linkage analysis is used to map the causative mutation and characterize an autosomal-recessive syndrome of focal epilepsy, dysarthria and mild to moderate intellectual disability in a consanguineous Arab-Israeli family associated with subtle cortical thickening. A pathogenic mutation identified in TBC1D24, a gene of unknown function which is expressed early in mouse brain is the potent modulator of primary axonal arborization and specification in neuronal cells and is consistent with phenotypic abnormality.