Effects of temporary low-dose galactose supplements in children aged 5-12 y with classical galactosemia: a pilot study.

BACKGROUND: Classical galactosemia is caused by severe galactose-1-phosphate uridyltransferase deficiency. Despite life-long galactose-restriction, many patients experience long-term complications. Intoxication by galactose and its metabolites as well as over-restriction of galactose may contribute to the pathophysiology. We provided temporary low-dose galactose supplements to patients. We assessed tolerance and potential beneficial effects with clinical monitoring and measurement of biochemical, endocrine, and IgG N-glycosylation profiles.

METHODS: We enrolled 26 patients (8.6 ± 1.9 y). Thirteen were provided with 300 mg of galactose/day followed by 500 mg for 2 wk each (13 patient controls).

RESULTS: We observed no clinical changes with the intervention. Temporary mild increase in galactose-1-phosphate occurred, but renal, liver, and bone biochemistry remained normal. Patients in the supplementation group had slightly higher leptin levels at the end of the study than controls. We identified six individuals as "responders" with an improved glycosylation pattern (decreased G0/G2 ratio, P < 0.05). There was a negative relationship between G0/G2 ratio and leptin receptor sOb-R in the supplementation group (P < 0.05).

CONCLUSION: Temporary low-dose galactose supplementation in children over 5 y is well tolerated in the clinical setting. It leads to changes in glycosylation in "responders". We consider IgG N-glycan monitoring to be useful for determining individual optimum galactose intake.