Five novel mutations in the L1 CAM gene in families with X linked hydrocephalus

Abstract

Five novel mutations have been identified in the gene encoding L1CAM, a neural cell adhesion protein, in families with X linked hydrocephalus (XHC). Interestingly, all five mutations are in the evolutionarily highly conserved Ig-like domains of the protein. The two framcshift mutations (S2insC and 9SSdelG) and the nonsense mutation (Trp276Ter) most probably result in functional null alleles and complete absence ofL1CAM at the cell surface. The two missense mutations (Tyrl94Cys and Pro24OLeu) may considerably alter the structure of the L1CAM protein. These data provide convincing evidence that XHC is genetically extremely heterogeneous.