Late infantile metachromatic leukodystrophy has gained great interest since 1958 when it was shown to be a lipidosis with an accumulation of sulfatides (sulfuric acid esters of cerebrosides) in various organs.2,8,17It is also possible now to base a reliable diagnosis during life on clinical symptoms and signs combined with laboratory tests.1,10,12,13As no full report of cases diagnosed during life has been found in the literature, we want to present a case thoroughly followed during 2 years and investigated clinically, histologically, and chemically. This case in abstract has previously been included in an earlier paper (Hagberg and Svennerholm, 1960, Case 1) and is the most thoroughly followed of 10 cases diagnosed and studied by our group. I. Report of a Case The girl was born Jan. 27, 1956, and was the only child in a healthy family. She was born at term with a birth weight of