What is Clasped thumbs and mental retardation?

Clasped thumbs and mental retardation: A syndrome with the followingcharacteristic features: (1) neurologically: mental retardation and aphasia (lack ofspeech) (2) limbs: adducted (clasped) thumbs, absent extensor pollicis longus and/orbrevis muscles to the thumb, shuffling gait, and leg spasticity (3) growth: small bodysize (4) skeleton: lumbar lordosis (sway back). The syndrome is inherited as an X-linkedtrait and so affects mainly boys. Alternative names include MASA syndrome (MASA stands formental retardation, aphasia, shuffling gait, and adducted thumbs), adducted thumb withmental retardation, congenital clasped thumb with mental retardation, and the Gareis-Masonsyndrome.