HLA class I and class II allelic profile of healthy Lebanese population

Background. This study examined the origin of present-day Lebanese using
high-resolution HLA class I and class II allele and haplotype
distributions. The study subjects comprised 152 unrelated individuals, and
their HLA class I and class II alleles and two-locus and five-locus
haplotypes were compared with those of neighboring and distant communities
using genetic distances, neighbor-joining dendrograms, correspondence, and
haplotype analyses. HLA class I (A, B, C) and class II (DRB1, DQB1) were
genotyped at a high-resolution level by PCR-SSP. Results. In total, 76
alleles across the five HLA loci were detected: A*03:01 (17.1%), A*24:02
(16.5%), B*35:01 (25.7%), C*04:01 (25.3%), and C*07:01 (20.7%) were the
most frequent class I alleles, while DRB1*11:01 (34.2%) and DQB1*03:01
(43.8%) were the most frequent class II alleles. All pairs of HLA loci
were in significant linkage disequilibrium. The most frequent two-locus
haplotypes recorded were DRB1*11:01~DQB1*03:01 (30.9%), B*35:01-C*04:01
(20.7%), B*35:01~DRB1*11:01 (13.8%), and A*24:02~B*35:01 (10.3%). Lebanese
appear to be closely related to East Mediterranean communities such as
Levantines (Palestinians, Syrians, and Jordanians), Turks, Macedonians,
and Albanians. However, Lebanese appear to be distinct from North African,
Iberian, and Sub-Saharan communities. Conclusions. Collectively, this
indicates a limited genetic contribution of Arabic-speaking populations
(from North Africa or the Arabian Peninsula) and Sub-Saharan communities
to the present-day Lebanese gene pool. This confirms the notion that
Lebanese population are of mixed East Mediterranean and Asian origin, with
a marked European component.