Review article: mucolipidosis IV

We review all reported cases of Mucolipidosis IV, add a new one, and present evidence for a generalized phospholipid storage. All phospholipids were increased in the liver, skin fibroblasts and urine. Lysobisphosphatydic acid which was markedly elevated in these samples was the only lipid stored in muscle. A slowly progressive neurological disease with mental retardation and corneal opacities, but lacking mucopolysaccharide excretion, skeletal changes and organomegaly should raise the suspicion of this disease. At this time, the diagnosis is made by EM studies of skin or conjunctiva which should be done if results of tests on serum or bone marrow for lysosomal diseases are normal. We found some of the typical inclusions in skin fibroblasts from an obligate carrier, which suggests that distinction between the homozygote and heterozygote may be difficult. Despite this, two succeeding pregnancies with normal outcomes were successfully monitored.