PRENATAL DIAGNOSIS OF HYPOPHOSPHATASIA - GENETIC, BIOCHEMICAL, AND CLINICAL STUDIES

  • 1 January 1978
    • journal article
    • research article
    • Vol. 30  (3) , 271-282
Abstract
Three approaches to the human prenatal diagnosis of the severe, early onset form of hypophosphatasia were considered. Two of these approaches, ultrasonography and the determination of the bone/liver isozymes of alkaline phosphatase (ALP) in cultured amniotic fluid cells, have proven useful diagnostically. The 3rd method, assay of the bone/liver isozyme activity or total activity in supernatant amniotic fluid, was not informative for the affected fetus studied. Failure to visualize a well-defined fetal skull after 16 wk of pregnancy when the level of .alpha.-fetoprotein in the amniotic fluid is normal should arouse the suspicion of hypophosphatasia. Because the disease is known to manifest clinical variability, studies to detect both the biochemical defect as well as the structural manifestations should be considered. The combined use of ultrasonography, analysis of amniotic fluid .alpha.-fetoprotein, and the measurement of the bone/liver ALP in cultured amniotic fluid cells appear to be the best approach to the prenatal diagnosis.