[MIM 303 350, 304 100, 307 000]

(CRASH syndrome, syndrome L1CAM, MASA syndrome)

The prevalence is estimated at 1/30,000. X-linked recessive transmission of mutations of the L1CAM gene (on Xq28) gene, coding for the L1 adhesion molecule which is mainly expressed  in the developing nervous system. More than 240 different mutations have been reported so far, which might explain the wide clinical spectrum. Approximately 7% of mutations are sporadic.

Light to severe congenital development disorder, X-linked, and characterized by:

-        hydrocephalus of varying severity,

-        intellectual deficit,

-        spasticity of the legs

-        adducted thumbs (50%).

The syndrome represents a spectrum of diseases including: hydrocephalus with stenosis of the aqueduct of Sylvius linked to X (HSAS), MASA syndrome, the X- linked complex type 1 hereditary spastic paraplegia syndrome and the complex agenesis of the corpus callosum.

A small number of patients have been reported as suffering from a combination of the L1 syndrome and an Hirchsprung disease (see this term). Patients may have minor symptoms, such as adducted thumbs or mild intellectual deficit, but they rarely have severe manifestations of the syndrome. Bilateral absence of the pyramids detected by MRI or autopsy is practically a pathognomonic feature of the syndrome.

Anesthetic implications:

mental retardation, hydrocephalus, spasticity

Reference:

Updated: August 2016