title: Three cases with L1 syndrome and two novel mutations in the L1CAM gene.
abstract: Mutations in the L1CAM gene have been identified in the following various X-linked neurological disorders: congenital hydrocephalus; mental retardation, aphasia, shuffling gait, and adducted thumbs (MASA) syndrome; spastic paraplegia; and agenesis of the corpus callosum. These conditions are currently considered different phenotypes of a single entity known as L1 syndrome. We present three families with L1 syndrome. Sequencing of the L1CAM gene allowed the identification of the following mutations involved: a known splicing mutation (c.3531-12G>A) and two novel ones: a missense mutation (c.1754A>C; p.Asp585Ala) and a nonsense mutation (c.3478C>T; p.Gln1160Stop). The number of affected males and carrier females identified in a relatively small population suggests that L1 syndrome may be under-diagnosed.
  
  
  CONCLUSIONS
  L1 syndrome should be considered in the differential diagnosis of intellectual disability or mental retardation in children, especially when other signs such as hydrocephalus or adducted thumbs are present.
authors.affiliation: Clinical Genetics Unit, Hospital Universitario Puerta del Mar, Cádiz, Spain. genetica.hpm.sspa@juntadeandalucia.es.
authors.forename: Rosario
authors.initials: R
authors.lastname: Marín
authors.affiliation: Department of Paediatrics, Hospital Universitario Puerta del Mar, Cádiz, Spain. leymartos@gmail.com.
authors.forename: Miriam
authors.initials: M
authors.lastname: Ley-Martos
authors.affiliation: Department of Paediatrics, Hospital Universitario de Jerez, Jerez, Spain. gemamegga@gmail.com.
authors.forename: Gema
authors.initials: G
authors.lastname: Gutiérrez
authors.affiliation: Division of Genetics, Human Anatomy Department, Universidad de Cádiz, Cádiz, Spain. felicidad.rodriguez@uca.es.
authors.forename: Felicidad
authors.initials: F
authors.lastname: Rodríguez-Sánchez
authors.affiliation: Progenie molecular S. L. Laboratory, Valencia, Spain. darroyo@progenie-molecular.com.
authors.forename: Diego
authors.initials: D
authors.lastname: Arroyo
authors.affiliation: Molecular Diagnosis Laboratory, Immunology Department, Hospital Universitario Puerta del Mar, Cádiz, Spain. mora.francisco@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Mora-López
mesh_terms: D002675:Child, Preschool; D005260:Female; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction; D015419:Spastic Paraplegia, Hereditary / Q000235:genetics*
chemical_list: D039842:Neural Cell Adhesion Molecule L1
keywords: Adducted thumbs; L1 syndrome; L1CAM; X-linked hydrocephalus; X-linked mental retardation