The composition of a mucus glycoprotein from meconium of cystic fibrosis, healthy pre-term and full-term neonates.

A high molecular mass mucus glycoprotein fraction (molecular mass greater than 1 million) which is a major component of meconium mucin, has been isolated from individual specimens collected from 20 healthy full-term infants, 19 premature infants and 19 infants with proven cystic fibrosis. The mucus glycoprotein fraction isolated from cystic fibrosis meconium had a significantly lower saccharide content than that isolated from specimens from healthy full-term infants but had a similar composition to that isolated from meconium of premature infants, gestational age 28-32 weeks. The composition of the glycoprotein fraction from the meconium of infants, gestational age 32-36 weeks, lay between that from cystic fibrosis and full-term. There is therefore a change or 'maturation' of epithelial mucin during gestation and it is hypothesised that the cystic fibrosis genetic lesion affects the maturation of epithelial secretion, resulting in the abnormal exocrine secretion associated with the disease.