The natural history of the severe form of Hunter's syndrome: a study based on 52 cases.

During a national survey of Hunter's syndrome, 52 boys with the severe form were ascertained. The average ages of onset and death were 2.47 and 11.77 years respectively. Most patients had a large head and short stature. Persistent diarrhoea was noted in 65 per cent of the patients. 76 per cent had an umbilical hernia. Right and left inguinal herniae were noted in 51 and 32 per cent respectively. Evidence of cardiovascular disease was found in 65 per cent of cases; and serious lower respiratory-tract disease occurred in 84 per cent. Induction of anaesthesia proved difficult or impossible in five boys. The disease pattern was dominated by the effects of neurological involvement, with initial developmental delay and behavioural disturbance, followed by regression, with convulsions and pyramidal tract signs. Death was due primarily to this neurodegenerative cachexia, with superimposed respiratory disease.