Perinatal Lethal Form of Hypophosphatasia

Background: Hypophosphatasia is a rare inherited metabolic disease which is sometimes fatal and is characterized by defective bone and teeth mineralization. The disease is due to loss of function mutation in the gene encoding tissuenonspecific alkaline phosphatase (TNAP or TNSALP). Case Report: We report a full term female baby whose parents were first cousins and her mother had a history of a previous abortion and one neonatal death with an antenatal diagnosis of achondrogenesis. The baby was born depressed and needed intubation in the labor room and mechanical ventilation in NICU. The baby had some dysmorphic features, lung hypoplasia and very low alkaline phosphatase level. Skeletal survey findings were consistent with hypophosphatasia. She had progressive deterioration of her respiratory condition and expired at the age of 25 days. Conclusion: The perinatal lethal form is the most severe type of hypophosphatasia. Prenatal testing for mutations in the TNSALP gene allows genetic counseling and prenatal diagnosis of the disease in families with severe forms of Hypophosphatasia.