A rare cause of non-immune hydrops fetalis: congenital sialidosis

Sialidosis is a rare congenital lysosomal storage disease with autosomal recessive transmission caused by a deficiency of alpha-N-acetyl-neuraminidase (sialidase). The findings begin in the intrauterine period in congenital type of sialidosis and the cases die in the postnatal period due to hydrops fetalis with multiorgan failure. Here, a case of premature baby born to a consanguineous parents and diagnosed as sialidosis with hydrops fetalis is presented. It was learned that the first pregnancy of the mother ended in spontaneous abortion and the second pregnancy was ended up with intrauterine exitus due to hydrops fetalis in the 28th gestational age. On the first physical examination, generalized edema, abdominal distantion due to hepatomegaly and generalized ascites was observed. Direct hyperbilirubinemia and cytoplasmic vacuoli in the lymphomonocyte series in both the bone marrow and peripheral blood smear were detected. The same vacuoli were also observed in hepatocytes in the hystopathological sections of the liver biopsy. Sialidosis was diagnosed by showing that there was no activity of sialidase enzyme in the fibroblast culture. The case died due to cardiorespiratory insufficiency on the 53rd day of admission. In cases with hydrops fetalis which can have various etiologies, careful examination of the peripheral smear is very important in the differential diagnosis in addition to detailed familial history and physical examination. (Turk Arch Ped 2012; 47:290-3)