SLC37A1 was not found to be mutated in patients with glycerol kinase deficiency, and despite mapping to the critical region of the autosomal recessive deafness locus, DFNB10 on chromosome 21q22.3, mutation analyses excluded it as the gene for DFNB10 [13]. The gene discussed is GK; the disease is hyperinsulinemic hypoglycemia, familial, 4.