HYDROXYLYSINE DEFICIENT COLLAGEN IN A FLOPPY BABY

Five disorders of collagen have been characterized. In four of these disorders the patients have had symptoms of Ehlers Danlos. Three families with lysyl hydroxylase deficiency have previously been reported. We are reporting an additional case diagnosed in infancy. This infant was investigated as a floppy baby but nerve and muscle were normal. Lysyl hydroxylase activity measured in sonicates of dermal fibroblasts was 10% of normal. The deficiency of hydroxylysine results in abnormal cross-linking of collagen molecules which may account for the symptomatology. The patient we are reporting eventually developed symptoms of Ehlers Danlos. This type of Ehlers Danlos is an autosomal recessive disorder in which one might expect to make an intrauterine diagnosis. Collagen abnormalities may thus be a cause of floppy baby syndrome and the delineation of a specific defect should be the goal of diagnostic studies.