A novel missense mutation in the L1CAM gene in a boy with L1 disease.

Abstract

A novel missense mutation of the L1CAM gene (Xq28) is described in an adult patient affected with severe mental retardation, spastic paraparesis, adducted thumbs, agenesis of corpus callosum and microcephaly (L1 disease). We detected a transition c2308G-->A in exon 18 that caused an amino acid change in codon 770. The patient's mother and two sisters were heterozygous for the same mutation. This newly described mutation predicts the substitution of an aspartate by asparagine (D770N) in the second fibronectin (Fn2) domain of the extracellular portion of the mature L1 protein. Even if amino acid substitution does not significantly change the physico-chemical properties of the Fn2 domain, it seems clear that the integrity of this domain is required to maintain the biological functions of the protein. The feature peculiar to this patient is the decelerated head growth post-natally, leading to microcephaly. Mutations of L1CAM associated with prolonged survival may hamper post-natal brain and head growth.

• Authors: A Simonati, F Boaretto, A Vettori, P Dabrilli, L Criscuolo, N Rizzuto, M L Mostacciuolo
• Journal: Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology (Neurol Sci) Vol. 27 Issue 2 Pg. 114-7 (Jun 2006) ISSN: 1590-1874 [Print] Italy
• PMID: 16816908 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Neural Cell Adhesion Molecule L1

Topics

• Abnormalities, Multiple (genetics)
• Adolescent
• Adult
• Base Sequence
• Brain (abnormalities)
• Child
• Humans
• Magnetic Resonance Imaging
• Male
• Mutation, Missense
• Neural Cell Adhesion Molecule L1 (genetics)
• Pedigree