Pathologic findings in fetal GM1 gangliosidosis.

A 24-week fetus with GM1 gangliosidosis (type 1) was studied using biochemical and histopathologic methods. Foam cells in viscera and placenta demonstrated widespread accumulation of a lipidlike material. By microscopy, central nervous system storage appeared confined to the retina and dorsal root ganglia, but the brain ganglioside content was measurably elevated compared with that of age-matched controls. These data, along with those of others, imply that, if the observed pathologic findings are irreversible, any attempts at intrauterine therapy must commence prior to the middle of the second trimester.