ARHGEF10 (rho guanine nucleotide exchange factor 10), also known as GEF10 or KIAA0294, is a 1,369 amino acid protein that contains one DBL-homology domain and is thought to play a role in myelination of peripheral nerves, specifically during development. ARHGEF10 is expressed as four alternatively spliced isoforms that are present at low levels in ovary, lung, testis and kidney, with considerably higher expression in the central and peripheral nervous systems. Defects in the gene encoding ARHGEF10 are the cause of slowed nerve conduction velocity (SNCV), an autosomal dominant disorders that is characterized by a reduction in nerve velocities resulting from lack of proper myelination.