At the 28th week of gestation a hydrops fetalis was first detected by ultrasound. At birth a generalized hydrops with Hurler-like craniofacial dysmorphism, hepatosplenomegaly and a moderate dystostosis multiplex was noted. High urinary excretion of oligosaccharides and a severe deficiency of neuraminidase and of beta-galactosidase in cultured skin fibroblasts could be found. Thus, a rare early infantile type of galactosialidosis was diagnosed. The patient died at the age of 3 months because of cardiac failure. The consanguineous but otherwise healthy parents received genetic counselling for further pregnancies and have been informed about the possibility of prenatal diagnosis. In view of this possibility, the parents decided to have more children. In the second pregnancy a severe combined enzyme deficiency had been detected and the pregnancy interrupted. In the third pregnancy prenatal diagnosis revealed normal fetal enzyme activities. It resulted in a healthy female child and in the fourth pregnancy reduced but still in the heterozygote level enzyme activities had been found, a healthy boy was born.