An Alu-mediated large deletion of the FUT2 gene in individuals with the ABO-Bombay phenotype

Citation
Y. Koda et al., An Alu-mediated large deletion of the FUT2 gene in individuals with the ABO-Bombay phenotype, HUM GENET, 106(1), 2000, pp. 80-85
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Molecular Biology & Genetics
Journal title
HUMAN GENETICS
ISSN journal
0340-6717 → ACNP
Volume
106
Issue
1
Year of publication
2000
Pages
80 - 85
Database
ISI
SICI code
0340-6717(200001)106:1<80:AALDOT>2.0.ZU;2-8
Abstract
Recently, we have found an allelic deletion of the secretor alpha(1,2)fucos yltransferase (FUT2) gene in individuals with the classical Bombay phenotyp e of the ABO system. The FUT2 gene consists of two exons separated by an in tron that spans approximately 7 kb. The first exon is noncoding, whereas ex on 2 contains the complete coding sequence. Since the 5' breakpoint of the deletion has previously been mapped to the single intron of FUT2, we have c loned the junction region of the deletion in a Bombay individual by cassett e-mediated polymerase chain reaction. In addition, the region from the 3' u ntranslated region of FUT2 to the 3' breakpoint sequence has been amplified from a control individual. DNA sequence analysis of this region indicates that the 5' breakpoint is within a free left Alu monomer (FLAM-C) sequence that lies 1.3 kb downstream of exon 1, and that the 3' breakpoint is within a complete A12e element (AluSx) that is positioned 1.5 kb downstream of ex on 2. The size of the deletion is estimated to be about 10 kb. There is a 2 5-bp sequence identity between the reference DNA sequences surrounding the 5' and 3' breakpoints. This demonstrates that an Alu-mediated large gene de letion generated by unequal crossover is responsible for secretor alpha(1,3 )fucosyltransferase deficiency in Indian Bombay individuals.