Defective GALE can cause Epimerase-deficiency galactosemia (EDG)

Stable Identifier
Homo sapiens
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Cytosolic UDP-galactose 4'-epimerase (GALE) catalyses the reversible interconversion of UDP-D-galactose (UDP-Gal) and UDP-glucose (UDP-Glc), the third reacton in the Leloir pathway of galactose metabolism. GALE can also catalyse the epimerisation of UDP-N-acetylglucosamine to UDP-N-acetylgalactosamine. The active form of the enzyme is a homodimer with one molecule of bound NAD per monomer (GALE:NAD+ dimer). Defects in GALE can cause Epimerase-deficiency galactosemia (EDG; MIM:230350), or type III galactosemia (diseases of galactose metabolism) whose clinical features include early-onset cataracts, liver damage, deafness and mental retardation. Historically, it was considered that there were two forms of GALE deficidency; a benign ("peripheral") form where there is no GALE activity in red blood cells and characterised by mild symptoms (Gitzelmann 1972) and a rarer "generalised" form with no detectable GALE activity in all tissues resulting in more severe symptoms (Holton et al. 1981). The disease is now considered to be a continuum (Openo et al. 2006).

Literature References
PubMed ID Title Journal Year
16385452 Epimerase-deficiency galactosemia is not a binary condition

Openo, KK, Schulz, JM, Vargas, CA, Orton, CS, Epstein, MP, Schnur, RE, Scaglia, F, Berry, GT, Gottesman, GS, Ficicioglu, C, Slonim, AE, Schroer, RJ, Yu, C, Rangel, VE, Keenan, J, Lamance, K, Fridovich-Keil, JL

Am. J. Hum. Genet. 2006
4644860 Deficiency of uridine diphosphate galactose 4-epimerase in blood cells of an apparently healthy infant. Preliminary communication

Gitzelmann, R

Helv Paediatr Acta 1972
7305435 Galactosaemia: a new severe variant due to uridine diphosphate galactose-4-epimerase deficiency

Holton, JB, Gillett, MG, MacFaul, R, Young, R

Arch. Dis. Child. 1981
Name Identifier Synonyms
galactosemia DOID:9870 Galactose intolerance, Galactosaemia
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