Infantile lethal neuraminidase deficiency (sialidosis).

An infant suffering from failure to thrive, hepatosplenomegaly, developmental retardation and early infantile death is described. The proposita demonstrated a type 2 early infantile sialidosis with onset at birth, and death at 4 months. A culture of the proband's fibroblasts showed neuraminidase deficiency, and low activity of the enzyme was found in the lymphocytes of both parents. A previous female child, born prematurely, died 6 h after birth and had hepatosplenomegaly and foam cells in the placenta. There is strong evidence that the inheritance of the disease is autosomal recessive.