UDP-glucose and UDP-galactose concentrations in cultured skin fibroblasts of patients with classical galactosaemia.

A very clear-cut reduction in UDP-galactose (UDPGal) levels in erythrocytes, skin fibroblasts and liver of patients with classical galactosaemia has been reported. As UDPGal is the galactosyl donor in glycoprotein and glycolipid synthesis, it has been suggested that an abnormality in these complex compounds may be the cause of some of the long-term complications of the disease. More recent work on erythrocytes, employing mainly HPLC rather than the enzyme methods used to measure UDPGal originally, casts doubt on the hypothesis because, although some reduction was still found, there was a large overlap between galactosaemic and normal distributions. We have reproduced the experiments on cultured skin fibroblasts at confluency, but measuring UDPGal and UDP-glucose (UDPGlc) by HPLC. There was no reduction in UDPGal levels in galactosaemic compared to control cell lines. The existence of a biologically significant depletion of UDPGal in galactosaemia remains in doubt.