L1CAM syndrome, CRASH syndrome, Corpus callosum hypoplasia-retardation-adducted thumbs-spasticity-hydrocephalus syndrome
Specialty
Pediatrics, neurology, medical genetics
Usual onset
Neonatal
Duration
Lifelong
Risk factors
Family history
Diagnostic method
Genetic testing
Treatment
Supportive
Prognosis
Varies depending on specific disorder
Frequency
Unknown; HSAS 1 per 30,000 male live births
L1 syndrome is a group of mild to severe X-linked recessive disorders that share a common genetic basis. The spectrum of L1 syndrome disorders includes X-linked complicated corpus callosum dysgenesis, spastic paraplegia 1, MASA syndrome, and X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS).[1][2] It is also called L1CAM syndrome (for the disorder's causative gene) and CRASH syndrome, an acronym for its primary clinical features: corpus callosum hypoplasia, retardation (intellectual disability), adducted thumbs, spasticity, and hydrocephalus.[2]
L1 syndrome can be caused by different variants in L1CAM,[3] the gene that provides the information that allows the body to produce L1 cell adhesion molecule (sometimes called the L1 protein).[3] The L1 cell adhesion molecule is a surface protein found on the surface of all neurons.[4] It allows neurons to bind to one another and create synapses (connections where information is passed on from the axons of one neuron to the dendrites and cell body of another).[4][5] As a result, L1 cell adhesion molecule is essential for the structural development of the brain and contributes to the ability to think, move, and develop memories.[4] The type and severity of L1CAM variant causing L1 syndrome in a particular person is directly related to the severity of symptoms and functional impairment that they experience.[6][7]
There is no cure for L1 syndrome, and prognosis is often poor.[8][9] Life expectancy for people with L1 syndrome can vary dramatically depending on the severity of the condition, with some dying shortly after birth and others reaching adulthood.[2] Treatment for people with L1 syndrome is supportive and aims to improve quality of life and minimize functional impairment.[10][3]
^"Orphanet: MASA syndrome". www.orpha.net. Retrieved 2019-03-13.
^ abc"L1 syndrome". Genetics Home Reference. Retrieved 2019-03-13.
^ abcCite error: The named reference GeneReviews was invoked but never defined (see the help page).
^ abc"Genetics Home Reference: L1CAM gene". Genetics Home Reference. Retrieved 2019-03-20.
^Helmstaedter, Moritz; Brecht, Michael; Kevin M. Boergens; Straehle, Jakob; Gour, Anjali; Schmidt, Helene (28 September 2017). "Axonal synapse sorting in medial entorhinal cortex". Nature. 549 (7673): 469–475. Bibcode:2017Natur.549..469S. doi:10.1038/nature24005. ISSN 1476-4687. PMID 28959971. S2CID 3578786.
^Cite error: The named reference Hofstra_2010 was invoked but never defined (see the help page).
^Itoh, Kyoko; Fushiki, Shinji (2015). "The role of L1cam in murine corticogenesis, and the pathogenesis of hydrocephalus". Pathology International. 65 (2): 58–66. doi:10.1111/pin.12245. ISSN 1440-1827. PMID 25641508.
^Marín, Rosario; Ley-Martos, Miriam; Gutiérrez, Gema; Rodríguez-Sánchez, Felicidad; Arroyo, Diego; Mora-López, Francisco (2015-11-01). "Three cases with L1 syndrome and two novel mutations in the L1CAM gene". European Journal of Pediatrics. 174 (11): 1541–1544. doi:10.1007/s00431-015-2560-2. ISSN 1432-1076. PMID 25948108. S2CID 11373848.
^Chidsey, Brandalyn A.; Baldwin, Erin E.; Toydemir, Reha; Ahles, Lauren; Hanson, Heather; Stevenson, David A. (2014). "L1CAM whole gene deletion in a child with L1 syndrome". American Journal of Medical Genetics Part A. 164 (6): 1555–1558. doi:10.1002/ajmg.a.36474. ISSN 1552-4833. PMID 24668863. S2CID 21955986.
^França Jr, Marcondes C.; Lopes-Cendes, Iscia; DAbreu, Anelyssa; Martinez, Alberto R. M.; Servelhere, Katiane R.; Faber, Ingrid; França Jr, Marcondes C.; Lopes-Cendes, Iscia; D'Abreu, Anelyssa (March 2014). "Clinical features and management of hereditary spastic paraplegia". Arquivos de Neuro-Psiquiatria. 72 (3): 219–226. doi:10.1590/0004-282X20130248. ISSN 0004-282X. PMID 24676440.
L1syndrome is a group of mild to severe X-linked recessive disorders that share a common genetic basis. The spectrum of L1syndrome disorders includes...
MASA syndrome is a rare X-linked recessive neurological disorder on the L1 disorder spectrum belonging in the group of hereditary spastic paraplegias...
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged...
A myelodysplastic syndrome (MDS) is one of a group of cancers in which immature blood cells in the bone marrow do not mature, and as a result, do not develop...
Tethered cord syndrome (TCS) refers to a group of neurological disorders that relate to malformations of the spinal cord. Various forms include tight filum...
the cord reaches its permanent position. Typically this is at the level of L1 or L2 (closer to the head), ranging due to normal anatomical variations anywhere...
A first language (L1), native language, native tongue, or mother tongue is the first language a person has been exposed to from birth or within the critical...
lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is...
the cause is unknown. Genetic risk factors may include Down syndrome, Li–Fraumeni syndrome, or neurofibromatosis type 1. Environmental risk factors may...
methylation of the L1 5' UTR. Human cell lines modeling the neurological disorder Rett syndrome, which carry MeCP2 mutations, exhibit increased L1 transposition...
pancreas. In the adult, the SMA arises anterior to inferior border of vertebra L1 (transpyloric plane). It is usually 1 cm lower than the celiac trunk. It initially...
involving neural cell adhesions and adhesion mechanisms. CRASH syndrome (or L1syndrome) is brought about by a mutation in the L1CAM gene on the x-chromosome...
output goes to the arms and trunk. The lumbar enlargement, located between L1 and S3, handles sensory input and motor output coming from and going to the...
the lymph nodes. Since PD-L1 proteins are regulated by N-glycosylation, the ZG16 works to bind directly to glycosylated PD-L1 proteins through its lectin...
behind the L1 ganglion which is responsible for ejaculation. Another example is endoscopic thoracic sympathectomy. Hyperhidrosis Raynaud syndrome Neuropathic...
maintained at least one language during childhood, the so-called first language (L1). The first language (sometimes also referred to as the mother tongue) is...
Injuries can be cervical 1–8 (C1–C8), thoracic 1–12 (T1–T12), lumbar 1–5 (L1–L5), or sacral (S1–S5). A person's level of injury is defined as the lowest...
Nerves in Pain Syndrome. The Medical Journal of Australia. 1972; 2:945–948. Maigne, R. Low back pain of thoracolumbar origin (T11-T12-L1). In: Maigne,...
"Enhanced expression of programmed death-1 (PD-1)/PD-L1 in salivary glands of patients with Sjögren's syndrome". The Journal of Rheumatology. 32 (11): 2156–63...
sides of the body (as found only in the thoracic region). They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of...
commonly injured include the cervical vertebrae (C1-C7), and the lumbar spine (L1-L5). Depending on the extent of the spinal cord injury, the symptoms may vary...
abduction of little finger) can also be elicited. Since the spinal cord ends at L1 or L2 vertebral levels, the job of nerve transmission is continued by spinal...
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