July 23, 2016
font size

Definition of Mental retardation and clasped thumbs

Mental retardation and clasped thumbs: A syndrome with the following characteristic features:
(1) Neurological: Mental retardation and aphasia (lack of speech);
(2) Limbs: Clasped (adducted) thumbs, absent extensor pollicis longus and/or brevis muscles to the thumb, shuffling gait, and leg spasticity;
(3) Skeleton: Lumbar lordosis (swayback);
(4) Growth: Small body size.

The syndrome is inherited as an X-linked recessive trait and so affects almost exclusively boys. Alternative names for the syndrome include MASA syndrome (MASA stands for mental retardation, aphasia, shuffling gait, and adducted thumbs), adducted thumb with mental retardation, congenital clasped thumb with mental retardation, and the Gareis-Mason syndrome.

Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/14/2012

Drug Medical Dictionary of Terms by Letter

Top RxList Drug News

Women's Health

Find out what women really need.

Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations