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Updated: Jul 12, 2026
Screening for Thermotoga maritima Membrane-Bound Pyrophosphatase Inhibitors
Published on: November 23, 2019
Positive maternal serum triple test screening in severe early onset hypophosphatasia
Ingrid Witters1, Philippe Moerman, Etienne Mornet
1Department of Obstetrics and Gynecology, University of Leuven, Leuven, Belgium. Ingrid.Witters@uz.kuleuven.ac.be
Objectives:
Hypophosphatasia is a rare heritable inborn error of metabolism characterized by a liver/bone/kidney alkaline phosphatase defective bone mineralization due to mutations in the tissue-non-specific alkaline phosphatase (TNS-ALP) gene. To date 128 mutations are described in the TNS-ALP gene located on the short arm of chromosome 1. The clinical presentation of hypophosphatasia is variable ranging from early onset lethal short-limb dwarfism to a late-onset presentation with fractures in childhood or adulthood.
Methods:
We report a pregnancy with a positive maternal serum triple test screening and a post-mortem pathological and molecular diagnosis of perinatal lethal hypophosphatasia.
Results:
Two heterogeneous missense mutations in the TNS-ALP gene were found, of which one was not previously described.
Conclusion:
This case report adds to the list of fetal malformations found after positive maternal serum triple test screening and reports a previously undescribed mutation in the TNS-ALP gene responsible for hypophosphatasia.
