SBF2 and glaucoma: Mutations in the MTMR13/SBF2 gene, which encodes a catalytically inactive member of the myotubularin family involved in heterodimerization with MTMR2, cause CMT4B2 (OMIM 604563), which has similar pathological features to CMT4B1, with additional glaucoma in some patients (80,81).