title: Characterization of the genomic structure of the human neuronal nicotinic acetylcholine receptor CHRNA5/A3/B4 gene cluster and identification of novel intragenic polymorphisms.
abstract: Genes coding for the alpha5, alpha3, and beta4 subunits (CHRNA5, CHRNA3, and CHRNB4) of the neuronal nicotinic acetylcholine receptors (nAChRs) are clustered on chromosome 15q24. Linkage of this chromosomal region to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), an idiopathic partial epilepsy, was reported in one family. Moreover, mutations in other neuronal nAChR subunit genes coding for the alpha4 (CHRNA4) and the beta2 (CHRNB2) subunits were associated with ADNFLE. Apart from the exon-intron structure of CHRNA3, the genomic organization of this gene cluster was unknown, making comprehensive mutational analyses impossible. The genomic structure of CHRNA5 and CHRNB4 is here reported. Moreover, two hitherto unknown introns were identified within the 3' untranslated region of CHRNA3, causing a partial tail-to-tail overlap with CHRNA5. Four novel intragenic polymorphisms were identified and characterized in the cluster.
authors.affiliation: Dipartimento di Biologia e Genetica per le Scienze Mediche, Università di Milano, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Duga
authors.forename: G
authors.initials: G
authors.lastname: Soldà
authors.forename: R
authors.initials: R
authors.lastname: Asselta
authors.forename: M T
authors.initials: MT
authors.lastname: Bonati
authors.forename: L
authors.initials: L
authors.lastname: Dalprà
authors.forename: M
authors.initials: M
authors.lastname: Malcovati
authors.forename: M L
authors.initials: ML
authors.lastname: Tenchini
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D017931:DNA Primers; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009474:Neurons / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011978:Receptors, Nicotinic / Q000235:genetics*; D020080:Tandem Repeat Sequences
chemical_list: D004247:DNA; D017931:DNA Primers; D009419:Nerve Tissue Proteins; D011978:Receptors, Nicotinic; C447158:CHRNA5 protein, human; C447159:CHRNB4 protein, human