ehlers-danlos syndrome (eds vi), kyphoscoliotic type a differential diagnosis to be considered in hyptonic newborns

ehlers-danlos syndrome (eds vi)(omim 225400) is an autosomal recessive disease of the connective tissue. it is characterized by severe hypotonia at birth, progressive kyphoscoliosis, skin hyperelasticity, joint hypermobility, microcornea, rupture of arteries and eye globe, and osteopenia. collagen lysyl hydroxylase is deficient in these patients. deficiency of the activity of lysyl hydroxylase, an enzyme involved in collagen biosynthesis, has been shown to be the biochemical defect in the disease which is caused by mutations in the plod1 gene. we report a 17-year-old boy, born to related parents, with severe kyphoscoliosis, scar formation, joint hypermobility, multiple joint dislocations, ocular globe rupture and history of severe infantile hypotonia. the differential diagnosis of ehlers-danlos vi, kyphoscoliotic type was initially suspected and confirmed by abnormal ratio of lysyl pyridinolines to hydroxylysyl pyridinolines, decreased hydroxylase activity in fibroblasts and molecular analysis. with the high rate of consanguineous marriages in our country and increased rate of autosomal recessive disorders we suggest physicians to consider eds vi as the differential diagnosis of severe infantile hypotonia. the analysis of urine pyridinolines can be used for confirmation which is highly specific, sensitive and inexpensive.