Disease Information for MASA Syndrome

MASA Syndrome; Adducted Thumbs-Mental Retardation; Congenital Clasped Thumb with Mental Retardation; Garies-Mason Syndrome; Mental Retardation, Aphasia, Shuffling Gait, Adducted Thumbs (MASA); X-linked Mental Retardation-Clasped Thumb Syndrome; MASA syndrome is an extremely rare inherited disorder that is one of several disorders known as X-linked mental retardation (XLMR) syndromes ; The acronym MASA stands for (M)ental retardation, (A)phasia, a diminished ability to communicate by speech, writing, and/or signs, (S)huffling manner of walking (gait), and (A)adducted thumbs, thumbs that are flexed inward toward the palm; Shuffling gait may be due to impaired control of voluntary movements and progressive rigidity of muscles in the legs (spastic paraplegia); Adduction of the thumbs may be due to absence or underdevelopment (hypoplasia) of certain muscles (extensor pollicis longus and/or brevis muscles) of the hand near the thumb; The symptoms and physical findings associated with MASA syndrome vary greatly from case to case; Affected individuals may not experience all of the main characteristics described above and may exhibit various other symptoms and physical findings such as abnormal widening (dilatation) of cavities (ventricles) within the brain and accumulation of excessive cerebrospinal fluid in the skull (hydrocephalus), mild short stature, abnormally increased inward curvature of the lower spine (exaggerated lumbar lordosis), and/or other skeletal abnormalities; According to the medical literature, mental retardation is the only feature that has been present in all documented cases of the disorder ; MASA syndrome is inherited as an X-linked recessive genetic trait; Therefore, the disorder is usually fully expressed in males only ; However, some females who carry one copy of the gene (heterozygotes) do appear to fully express the disease, while some others may exhibit only some milder symptoms associated with the disorder such as dull intelligence and/or adducted thumbs; -------[NORD]---

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