Adducted thumb syndrome. Report of a new case and a diagnostic approach.

We report on a female newborn baby with a "myopathic" stiff face, open mouth, high-arched palate, microgenia, generalized muscular hypotonia, limited extension of elbows, wrists and knees, flexed adducted thumbs, velopharyngeal insufficiency, and hypertrichosis. Death occurred at 3 months due to respiratory insufficiency. Muscular biopsy revealed myopathic abnormalities.