title: HLA-DRB1, -DQA1 and -DQB1 alleles and haplotypes in first-generation Pakistani immigrants in Norway.
abstract: Human leucocyte antigen (HLA) polymorphisms among immigrants from Pakistan have not been well investigated. Immigration to Norway started in the late 1960s for working purposes. From 1975, immigration was mainly for marriages and family reunion. When recruiting couples for a birth cohort study, we ended up with 65.5% of the 374 parents genotyped being closely related. This was also reflected in that 21% of newborns were homozygotes for their DRB1-DQA1-DQB1 genotype. For being able to study HLA class II genes frequencies among unrelated individuals, we had to exclude 195 of the parents from data analysis. High-resolution typing for the DRB1 locus, low/intermediate for the DQA1 locus and resolution genotyping for the DQB1 locus were performed in all the 179 parents and their newborns from the Punjab province of Pakistan. We identified 25 DRB1, nine DQA1 and 14 DRB1 alleles in the 179 unrelated parents included in our analysis. The most frequent alleles were DRB1*03:01:01 (15.9%) and DRB1*07:01:01 (15.9%), DQA1*01:03 (22.1%) and DQB1*02:01:01 (26.0%). Forty-one haplotypes were identified, including DRB1*13:02:01-DQA1*01:02-DQB1*06:03:01, not earlier reported. Supported by the few earlier reports on Pakistani groups living in Pakistan, it appears that alleles found among those living in Norway are of Indo-European or mixed ethnic origin. This study provides the first comprehensive report of HLA class II alleles and haplotypes in Norwegian Pakistani immigrants. When the unrelated parents were compared with all parents genotyped, there were, however, no significant differences in allele frequencies, confirming that consanguineous marriages are usual in Pakistan.
authors.affiliation: Department of Pediatric Research, Oslo University Hospital, Rikshospitalet, Oslo, Norway. kjersti.skjold.ronningen@gmail.com
authors.forename: K S
authors.initials: KS
authors.lastname: Rønningen
authors.forename: S E
authors.initials: SE
authors.lastname: Yap
authors.forename: K
authors.initials: K
authors.lastname: Brandal
authors.forename: A
authors.initials: A
authors.lastname: Stormyr
authors.forename: B A
authors.initials: BA
authors.lastname: Lie
authors.forename: T
authors.initials: T
authors.lastname: Rasmussen
authors.forename: B
authors.initials: B
authors.lastname: Stray-Pedersen
authors.forename: H E
authors.initials: HE
authors.lastname: Akselsen
mesh_terms: D000483:Alleles; D054242:Emigrants and Immigrants; D005260:Female; D005828:Genetics, Population; D059848:HLA-DQ alpha-Chains / Q000235:genetics*; D059866:HLA-DQ beta-Chains / Q000235:genetics*; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008297:Male; D009664:Norway; D010154:Pakistan
chemical_list: D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains