title: A novel activation-induced cytidine deaminase gene mutation in a Tunisian family with hyper IgM syndrome.
abstract: Mutations in activation-induced cytidine deaminase can cause an autosomal recessive form of hyper-IgM syndrome. We have examined a Tunisian family composed of six members: two healthy parents, their two healthy daughters and two affected sons. We found a homozygous transversion G to T in the two sons while heterozygosity for the mutation was found in all other family members. This alteration is localised in intron 2 at the +1 position resulting in defective splicing. Use of various intronic cryptic splice-sites led to expression of various aberrant mRNA species.
  
  
  CONCLUSIONS
  This is a novel mutation found in the gene encoding for activation-induced cytidine deaminase in a Tunisian family with hyper-IgM type 2 syndrome. This alteration leads to the use of two cryptic splicing sites causing the formation of two different mRNA species.
authors.affiliation: Istituto di Medicina Molecolare A. Nocivelli, Clinica Pediatrica, Università di Brescia, Piazzale Spedali Civili 1, 25123 Brescia, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fiorini
authors.forename: Sawssen
authors.initials: S
authors.lastname: Jilani
authors.forename: Claretta Gioia
authors.initials: CG
authors.lastname: Losi
authors.forename: Antonietta
authors.initials: A
authors.lastname: Silini
authors.forename: Silvia
authors.initials: S
authors.lastname: Giliani
authors.forename: Simona
authors.initials: S
authors.lastname: Ferrari
authors.forename: Luigi D
authors.initials: LD
authors.lastname: Notarangelo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Plebani
authors.forename: Taher
authors.initials: T
authors.lastname: Sfar
authors.forename: Ahmed
authors.initials: A
authors.lastname: Helal
mesh_terms: D000328:Adult; D002648:Child; D003564:Cytidine Deaminase / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D006942:Hypergammaglobulinemia / Q000201:enzymology* / Q000235:genetics*; D007075:Immunoglobulin M / Q000097:blood / Q000235:genetics*; D007438:Introns; D008297:Male; D009154:Mutation; D012326:RNA Splicing; D035781:Siblings
chemical_list: D007075:Immunoglobulin M; D003564:Cytidine Deaminase