Phosphorylase b kinase deficiency in a boy with glycogenosis affecting both liver and muscle

A boy with marked hepatomegaly and motor weakness was investigated for glycogen storage disease. Glycogen accumulation was demonstrated in both liver and muscle and there was a deficiency of phosphorylase b kinase activity. On the basis of biochemical findings, an autosomal recessive mode of inheritance was considered likely, rather than the more common X-linked variant, with primarily liver involvement.