Prenatal hypophosphatasis: ultrasoundfindings and diagnosis

Abstract

Hypophosphatasia is a skeletal dysplasia caused by mutations in the ALPL gene that impair bone mineralization. The nonspecific nature of ultrasound findings and their overlap with other skeletal dysplasias make prenatal diagnosis challenging. We report the case of a 37-year-old pregnant woman at 20 weeks’ gestation with ultrasound findings suggestive of severe skeletal dysplasia with suspected lethality. Amniocentesis showed a normal prenatal karyotype. A cesarean section was performed at 38 weeks, resulting in a live newborn with micromelia and a hypoplastic
thorax. Postnatal studies revealed decreased alkaline phosphatase levels, and genetic testing identified a homozygous c.892G>A p.(Glu298Lys) mutation in the ALPL gene, confirming the diagnosis of prenatal hypophosphatasia.