Other erythrocyte enzyme deficiencies associated with non-haematological symptoms: phosphoglycerate kinase and phosphofructokinase deficiency

Phosphoglycerate kinase (PGK) deficiency is associated with hereditary haem olytic anaemia and often with central nervous system dysfunction and/or myo pathy. Twenty-three families have been discovered with this condition. Nine have manifested both symptoms, six only haemolysis, and seven central nerv ous system dysfunction and/or myopathy without haemolysis; one case is asym ptomatic. Among them, the structural abnormalities of 14 mutants, including II missense mutations, I gene deletion, I gene insertion, and I splicing m utation, have been identified. The correlation between the phenotypic and s tructural differences in PGK deficiency remains to be defined. Splenectomy obviates transfusion in most patients but does not correct the haemolytic d isorder. Phosphofructokinase (PFK) deficiency is associated with myopathy a nd/or haemolysis. More than half reported had the typical features of glyco gen storage disease type VII (Tarui disease). The other cases exhibited myo pathy alone, haemolytic anaemia alone, or no clinical symptom at all, Eight missense, I nonsense, I frameshift and 5 splicing mutations have been dete rmined in the PFK-M gene. In classic PFK-M deficiency, the avoidance of und ue exertion is the key to prevent muscle symptoms.