TBC1D24 and Its Related Epileptic Encephalopathy

TBC1D24, mapped to 16p13.3, encodes a protein containing a Tre2/Bub2/Cdc16 (TBC) domain, belonging to the super-family of Rab GTPase activating proteins (Rab-GAP). These proteins regulate various functions, including the regulation of the traffic of the vesicular membrane. Several TBC1D24 mutations have been related to autosomal recessive neurological disorders, including severe developmental encephalopathies with malignant early childhood epilepsy, benign epilepsy, epileptic encephalopathy, and a complex neurological syndrome characterized by deafness, onychodystrophy, bone and neurological degeneration. Mutations of TBC1D24 have also been reported in patients with nonsyndromic deafness with dominant or recessive inheritance. Mechanisms underlying TBC1D24-associated disorders and the functions of TBC1D24 products in the generation of such complex spectrum of diseases remain partly unclear and future studies are needed to clarify this aspect, in order to improve the management of seizures and for the prevention of complication (including death) of newly diagnosed patients affected by TBC1D24-related disorders.