Human glycerol kinase deficiency: enzyme kinetics and fibroblast hybridization

Glycerol kinase deficiency has been associated with neuromuscular, skeletal and adrenal abnormalities and has also been seen in individuals without these clinical findings. Examination of residual enzyme activity in patients' liver, kidney, leukocytes and fibroblasts showed a generalized, heritable defect: the apparent Km for glycerol was increased 5-200-fold over control values, whereas the apparent Km for ATP was not significantly altered. This kinetic defect was similar in fibroblasts from clinically different individuals with this inborn error of metabolism. Hybridization of fibroblasts from these individuals showed no evidence of complementation for glycerol kinase activity.