Lumbar kyphosis in Hunter's disease (MPS ii).

Although radiological involvement of the lower dorsal and upper lumbar vertebrae is common in the severe form of Hunter's disease (MPS II), there are reports in the literature that clinical kyphosis does not occur. We report a boy with marked clinical kyphosis in whom the diagnosis of MPS II was proved by demonstrating a severe deficiency of serum and leucocyte iduronate-sulphate sulphatase and an accelerated incorporation of radiosulphate into his cultured fibroblast glycosaminoglycans, which could not be corrected by the product of other typed reference MPS II cells. The existence of several other genetic diseases, sometimes complicated by kyphosis, was excluded by assay of fibroblast lysosomal enzymes.