Mondo Description MASA syndrome (Mental retardation, Aphasia, Spastic paraplegia, Adducted thumbs) is a historical term used to describe a phenotype now considered to be part of the X-linked L1 clinical spectrum (L1 syndrome). MASA is characterized by mild to moderate intellectual deficit, delayed development of speech, hypotonia progressing to spasticity or spastic paraplegia, adducted thumbs, and mild to moderate distension of the cerebral ventricles.

Uniprot Description An X-linked recessive syndrome with a highly variable clinical spectrum. Main clinical features include spasticity and hyperreflexia of lower limbs, shuffling gait, mental retardation, aphasia and adducted thumbs. The features of spasticity have been referred to as complicated spastic paraplegia type 1 (SPG1). Some patients manifest corpus callosum hypoplasia and hydrocephalus. Inter- and intrafamilial variability is very wide, such that patients with hydrocephalus, MASA, SPG1, and agenesis of corpus callosum can be present within the same family.

Disease Ontology Description A hereditary spastic paraplegia that is characterized by hydrocephalus, spasticity of the lower limbs, adducted thumbs, aphasia, seizures, agenesis of the corpus callosum and intellectual disability in the mild to moderate range.