Clinical Department of Pediatrics, Sestre milosrdnice University Hospital Center, Vinogradska cesta 29, 10000 Zagreb, Croatia

Abstract

MASA syndrome (OMIM 303350) is a rare X-linked recessive neurologic disorder, also called CRASH syndrome, spastic paraplegia 1 andGareis-Mason syndrome. The acronym MASA describes four major signs: Mental retardation, Aphasia, Shuffl ing gait and Adductedthumbs. A more suitable name for this syndrome is L1 syndrome because the disorder has been associated with mutations in theneuronal cell adhesion molecule L1 (L1CAM) gene. The syndrome has severe symptoms in males, while females are carriers becauseonly one X chromosome is aff ected. The aim of this report is to show similarities and diff erences in clinical manifestations betweentwins with the L1CAM gene mutation and to emphasize the importance of genetic counseling. Our patients were dizygotic twins bornprematurely at 35 weeks of gestation. Pregnancy was complicated with early bleeding and gestational diabetes. Immediately afterbirth, hypertonia of lower extremities was observed in both twins. Sixteen-year clinical follow up showed spastic paraparetic form withshuffl ing gait, clumsiness, delayed speech development, lower intellectual functioning at the level of mild to moderate mental retardation,primary nocturnal enuresis, behavioral and sleep disorder (more pronounced in the second twin). Magnetic resonance imagingof the brain showed complete agenesis of the corpus callosum, complete lack of the anterior commissure, and internal hydrocephalus.Electroencephalograms showed nonspecifi c slower dysrhythmic changes. Kidney ultrasound showed mild dilatation in the channelsystem of both kidneys in both twins. Ophthalmologic examination was normal. Molecular genetic testing identifi ed homozygousintron 26 L1CAM gene IVS26-12G→A mutation in both twins. The mother is carrier of the same heterozygous mutations. In conclusion,our patients, fraternal twins, show similar clinical changes typical of the MASA syndrome. After identifying the specifi c geneticmutations, this family has become eligible for genetic counseling and informative for prenatal diagnosis.