An evaluation of mucus glycoproteins in the larynges of victims of sudden infant death syndrome.

Larynges from 24 victims of Sudden Infant Death Syndrome (S.I.D.S.) and 10 controls, with ages ranging from two days to 24 weeks in the controls and from two to 116 weeks in the S.I.D.S. victims, were transversely, step-serially sectioned and then stained to show acid, neutral and mixed mucus glycoproteins. The proportion of sulphated mucus glycoprotein and sialylated mucus glycoprotein to total acid mucus glycoprotein was determined by the use of various staining techniques and a comparison was made for each type between S.I.D.S. and controls. The differences were significant with a mean of 27 per cent in the controls compared to 59 per cent in the S.I.D.S. for sulphomucin (difference 32 per cent; standard error of difference 6 per cent; p < 0.01) and 73 per cent in the controls compared to 41 per cent in the S.I.D.S. larynges (difference 32 per cent; standard error of difference six per cent; p < 0.01) for sialomucin. The results suggest that sulphated mucus glycoprotein is secreted in excess in some victims of Sudden Infant Death Syndrome.