galactosemia

Pathology

• cataracts are secondary to accumulation of galactitol in the lenses

Genetics

• galactose-1-phosphate uridyltransferase deficiency
  • nearly all cases
  • fatty cirrhotic liver
• galactokinase (GALK1) deficiency (uncommon) {type 2}
• UDP-glucose-4-epimerase deficiency (rare)

Clinical manifestations

• galactose-1-phosphate uridyltransferase deficiency
  • nausea/vomiting & diarrhea following ingestion of milk
  • onset of symptoms after a few days to weeks of life
  • mental retardation
  • failure to thrive
  • jaundice
  • juvenile cataracts
• galactokinase (GALK1) deficiency:
  • cataracts is the only manifestation
  • congenital cataracts during infancy
  • presenile cataracts in the adult population
• UDP-glucose-4-epimerase deficiency
  • relatively asymptomatic

Laboratory

• decreased erythrocyte galactose-1-phosphate uridyltransferase (GALT) activity - screening programs for galactosemia based upon assay for GALT
• urine chemistries
  • galactosuria
  • aminoaciduria
  • albuminuria
• GALT gene mutation

4) see ARUP consult

More general terms

• carbohydrate inborn error of metabolism

More specific terms

• galactosemia 2 (galactokinase deficiency)
• galactosemia 3 (epimerase-deficiency galactosemia)

Database

• OMIM: https://mirror.omim.org/entry/230200
• OMIM: https://mirror.omim.org/entry/230400