Red cell phosphoglucomutase (PGM)-deficiency: hereditary defect of the PGM1-locus.

Reduced phosphoglucomutase (PGM) activity (approximately 25% of normal) was found in erythrocytes from a healthy newborn infant. The PGM activity was also diminished (approximately 50% of normal) in the erythrocytes of the parents. No PGM1 isoenzymes were found in the erythrocytes of the propositus, as demonstrated by the starch gel electrophoresis. Both parents showed a normal distribution of the PGM1 isoenzymes. We propose a heterozygous state in the parents for a gene determining the activity of the PGM1 isoenzymes and that no activity of the PGM1 isoenzyme could be detected in erythrocytes of the propositus because of his homozygous state. In neonatal screening for galactosaemia red cell PGM deficiency gives false positive results, as does glucose-6-phosphate dehydrogenase deficiency.