GALK1 and hyperinsulinemic hypoglycemia, familial, 4: Abnormally low GALT, GALE, or GALK1 activities result in a positive newborn screen; however, a positive galactosemia screening does not indicate only the possibility of enzyme deficiency, but is perhaps as a reflection of portosystemic shunt or liver dysfunction, e.g. citrin deficiency and Fanconi-Bickel syndrome [2].