Hyperphosphatasemia in early diagnosed infantile GM1 gangliosidosis presenting as transient hydrops fetalis.

The authors report a case of unsuspected fetal storage disorder initially diagnosed by placental examination performed because of a transient ascites at 28 weeks of gestation. At birth mild dysmorphic features and gradual neurological deterioration were observed. Highly elevated alkaline phosphatase levels were repeatedly noticed. Deficiency of beta-galactosidase was documented confirming GM1 gangliosidosis. Previous reports described the placental pathology after positive prenatal diagnoses of lysosomal diseases. In the present case, the postnatal diagnosis was made in view of the placental pathologic findings. Our observation indicates the need for thorough investigations in hydrops fetalis, in search for metabolic diseases.