A congenital variant of glycogenosis type IV.

Three related patients are described with glycogenosis type IV with an unusual clinical presentation resulting in perinatal death. Stored material showed birefringent Maltese crosses and was present in skeletal muscles, heart, central nervous system, and liver. Muscular dysfunction resulted in a fetal hypokinesia sequence with arthrogryposis and lung hypoplasia. A subdivision of glycogenosis type IV in four subtypes is proposed, based on age of onset. Measurement of the enzyme activities in different tissues does not permit, at the moment, a distinction between the subtypes.