Chorionic villi ultrastructure in the prenatal diagnosis of glycogenosis type II

To perform the ultrastructural examination of a chorionic villi biopsy as a predictor of foetal involvement in the infantile form of glycogenosis type II (Pompe disease).

Ultrastructural, biochemical and genetic analyses were performed on chorionic villi biopsies of three consecutive pregnancies in a woman with a previous child affected by Pompe disease.

In the only affected foetus, glycogen storage was observed in fibrocytes and endothelial cells of a chorionic villi sample at 11 week's gestation. Severe multi-organ involvement was demonstrated in the tissues of the aborted foetus. No abnormal material was found in the chorionic samples of two subsequent pregnancies, and a healthy boy and girl were born at term and remain unaffected. Both exhibited a partial reduction in acid maltase and were carriers of the maternal mutation.

Ultrastructural findings correlated with biochemical and genetic results, providing a clear and early indicator of the definite diagnosis for future pregnancy management or an early therapeutic approach.