Editor—Galactosaemia is an autosomal recessively inherited metabolic disorder caused by a defect in the galactose-1-phosphate uridyltransferase (GALT) enzyme. Absence or severe reduction of GALT activity results in classical galactosaemia (G/G) while an approximately half reduction of enzyme activity leads to the Duarte variant of galactosaemia (D/D). Mutation Q188R was found to be the most common molecular defect among classical galactosaemia patients,1 whereas N314D was predominantly detected in Duarte galactosaemia patients.2 In recent studies, the Duarte (D2) allele with 50% of normal GALT activity and the Los Angeles (D1) allele with 110-130% of normal GALT activity were characterised as having nucleotide alterations in addition to N314D.3 A study of the GALT gene from 31 unrelated galactosaemia families and from 504 control subjects is reported.

Thirty three patients and their relatives from the Czech and Slovak Republics were investigated (100% of all known galactosaemia patients). All families were white. There is no galactosaemia newborn screening in our country. Clinical onset of classical galactosaemia began in all patients in the neonatal period. The patients were identified with typical symptoms of classical galactosaemia (vomiting, failure to thrive, icterus, sepsis, hepatosplenomegaly, cataracts) and diagnosed by erythrocyte GALT assay (residual GALT activity less than 3% of the control value).4 A total of 504 non-galactosaemic subjects from the Czech Republic, including healthy donors and parents of α-1-antitrypsin deficiency patients, were used as a control group for population screening of …