A new biallelic polymorphism in intron 1 of the CHRNA4 gene may cause erroneous genotyping of a closely linked CA repeat marker

• Published in: Molecular and cellular probes 2000-12, Vol.14 (6), p.373-380
• Main Authors: Bonati, MT, Duga, S, Asselta, R, Ferini-Strambi, L, Oldani, A, Zucconi, M, Malcovati, M, Dalprà, L, Tenchini, ML
• Format: Article
• Language: English
• Subjects: ADNFLE, neuronal nicotinic acetylcholine receptor α4 subunit gene, polymorphism, haplotype, linkage analysis; Alleles; Base Sequence; Chromosome Mapping; DNA Primers - chemistry; Family; Female; Genetic Markers; Genotype; Haplotypes; Humans; Introns - genetics; Male; Molecular Sequence Data; Pedigree; Polymerase Chain Reaction; Polymorphism, Genetic - genetics; Receptors, Nicotinic - genetics; Tandem Repeat Sequences - genetics
• ISSN: 0890-8508; 1096-1194
• DOI: 10.1006/mcpr.2000.0327

A new polymorphism in intron 1 of the neuronal nicotinic acetylcholine receptor α4 subunit gene (CHRNA4) was identified. It consists of a G to T substitution located in the downstream flanking region of a previously reported CA repeat marker. This polymorphism whose frequency is about six percent in a control population occurs near the 3′ end of the reverse primer generally used to type the CA repeat marker. Data are presented showing that the newly identified polymorphism causes erroneous genotyping of the CA repeat marker which can alter the results of linkage analysis forCHRNA4 . The use of a different reverse primer located 34 nt downstream of the published sequence overcame errors in genotyping and identified two novel alleles of the CA repeat marker. Re-typing of the marker with the new proposed primer pair in a Caucasian control population of 107 unrelated individuals was also performed