Pyridoxal‐5′‐phosphate and alkaline phosphatase
Lawrence Lumeng – 1 March 1986 – Markedly increased circulating concentrations of pyridoxal‐5′‐phosphate (PLP) were found in each of 14 patients representing all clinical forms of hypophosphatasia, an inborn error characterized by deficient activity of the tissue‐nonspecific (bone/liver/kidney) isoenzyme of alkaline phosphatase (AP). The mean PLP concentration in plasma was 1,174 nM (range, 214 to 3,839 nM) in the patients and 57 ± 26 nM (mean ± S.D.) in 38 control subjects.