Marshall-Smith syndrome: new aspects.

A 4-year-old girl with the Marshall-Smith syndrome (MSS) is described. A muscle biopsy was performed because of hypotonia and muscular weakness. Selective hypoplasia of type IIa and IIb fibers was found. Additional not previously reported findings in this girl were a partial growth hormone deficiency, a partial villous atrophy of the small bowel and a pronounced dicarboxylic aciduria. The significance of these findings in MSS is not clear and the results of similar investigations in other MSS patients have to be awaited.