Summary
We measured plasma levels of pyridoxal-5′-phosphate (PLP), a cofactor form of vitamin B6 and apparent natural substrate for alkaline phosphatase (ALP), in carriers and in non-carriers of the severe perinatal and infantile forms of hypophosphatasia, both before and after an oral load of pyridoxine (i.e. 1/3 mg/kg body weight). The assignment of carrier status was determined by serum ALP activity, level of serum inorganic phosphate, and if necessary urinary phosphoethanolamine excretion. Plasma PLP levels were significantly increased in the carriers both before and especially after B6 loading.
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Chodirker, B. N., Evans, J. A., Seargeant, L. E., Cheang, M. S. and Greenberg, C. R. Hypophosphatemia in infantile hypophosphatasia: Implications for carrier diagnosis and screening.Am. J. Hum. Genet. 46 (1990) 280–285
Coburn, S. P. and Mahuren, J. D. A versatile cation-exchange procedure for measuring the seven major forms of vitamin B6 in biological samples.Anal. Biochem. 129 (1983) 310–317
Coburn, S. P. and Whyte, M. P. Role of phosphatases in the regulation of vitamin B6 metabolism in hypophosphatasia and other disorders. In Leklem, J. E. and Reynolds, R. D. (eds.),Clinical and Physiological Applications of Vitamin B6, Liss, New York, 1988, pp. 65–93
Fedde, K. N., Lane, C. C. and Whyte, M. P. Alkaline phosphatase is an ectoenzyme which degrades natural substrates at micromolar concentration and physiologic pH in human osteosarcoma (SAOS-2) cells.Arch. Biochem. Biophys. 264 (1988) 400–409
Fraser, D. Hypophosphatasia.Am. J. Med. 22 (1957) 730–746
MacPherson, R. I., Kroeker, M. and Houston, C. S. Hypophosphatasia.J. Can. Assoc. Radiol. 23 (1972) 16–26
Moore, C. A., Ward, J. C., Rivas, M. L., Magill, H. L. and Whyte, M. P. Infantile hypophosphatasia: Autosomal recessive transmission to two related sibships.Am. J. Med. Genet. 36 (1990) 15–22
Rasmussen, K. Phosphorylethanolamine and hypophosphatasia.Danish Med. Bull. 15 (suppl. II) (1968) 1–112
Schideler, C. D. Vitamin B6: An overview.Am J. Med. Technol. 49 (1983) 17–22
Whyte, M. P. Hypophosphatasia. In Scriver, C. R., Beaudet, A. L., Sly, W. S., and Valle, D. (eds.),The Metabolic Basis of Inherited Disease, 6th edn., McGraw-Hill, New York, 1989a, pp. 2843–2856
Whyte, M. P. Alkaline phosphatase: Physiologic role explored in hypophosphatasia. In Peck, W. A. (ed.),Bone and Mineral Research, 6th edn., Elsevier Science Publishers, Amsterdam, 1989b, pp. 175–218
Whyte, M. P. Pediatric forms of hypophosphatasia. In Kleerekoper, M. and Krane, S. M. (eds.),Clinical Disorders of Bone and Mineral Metabolism, Mary Ann Liebert, New York, 1989c, pp. 383–391
Whyte, M. P., Mahuren, J. D., Fedde, K. N., Cole, F. S. and Coburn, S. P. Perinatal hypophosphatasia: Tissue levels of vitamin B6 are unremarkable despite markedly increased circulating concentrations of pyridoxal-5′-phosphate (evidence for an ectoenzyme role for tissue non-specific alkaline phosphatase).J. Clin. Invest. 81 (1988) 1234–1239
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Chodirker, B.N., Coburn, S.P., Seargeant, L.E. et al. Increased plasma pyridoxal-5′-phosphate levels before and after pyridoxine loading in carriers of perinatal/infantile hypophosphatasia. J Inherit Metab Dis 13, 891–896 (1990). https://doi.org/10.1007/BF01800216
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DOI: https://doi.org/10.1007/BF01800216