Carbohydrate-deficient transferrin in galactosaemia

Carbohydrate‐deficient isoforms of transferrin (CDT) were examined in Guthrie cards from patients with galactosaemia before and during dietary treatment for up to 9 y. In untreated patients the CDT values were elevated due to abnormal asialo‐ and/or disialotransferrin. During treatment, the CDT levels were normal except on a few temporary occasions. Galactose or its close metabolites did not inhibit two relevant glycosyltransferases in vitro, and their levels were not correlated to the CDT values. The transferrin isoform changes in untreated patients were similar to, but less pronounced than in CDG syndrome type I.