EARLY-INFANTILE GALACTOSIALIDOSIS - CLINICAL, BIOCHEMICAL, AND MOLECULAR OBSERVATIONS IN A NEW PATIENT

Few patients with the early-infantile form of galactosialidosis have b een described to date. Presented here is the first Italian case. Fetal hydrops was detected by ultrasound at week 24 of gestation, At birth, the infant presented with hypotonia, massive edema, a flattened coars e facies, telangiectasias, and hepatosplenomegaly, but no dysostosis m ultiplex, The patient died 72 days postpartum Excessive sialyloligosac charides in urine, as well as vacuolation of lymphocytes and eosinophi lic granulocytes in peripheral blood, were indicative of a lysosomal s torage disease, In the patient's fibroblasts, both alpha-neuraminidase and beta-galactosidase activities were severely reduced, and cathepsi n A activity was <1% of control levels, confirming the biochemical dia gnosis of galactosialidosis. However, in contrast to previously report ed early-infantile cases, a normal amount of protective protein/cathep sin A mRNA was detected on Northern blots. This mutant transcript was translated into a precursor protein that was not processed into the ma ture enzyme and lacked both protective and catalytic activities. (C) 1 996 Wiley-Liss, Inc.