Forearm fullness in Coffin-Lowry syndrome: a misleading yet possible early diagnostic clue.

Two unrelated infants with delayed development and suspected abnormalities of the upper limbs were found to have the Coffin-Lowry syndrome. Both had marked fullness of the forearms in the presence of normal skeletal structures which resulted from increased subcutaneous fat. Although initially misleading, the forearm changes may serve as an early diagnostic clue in this disorder.