Stayoussef et al. (2009) investigated the association of HLA class II (DRB1 and DQB1) haplotypes with type 1 diabetes (T1D) in Bahrain (Arabian Peninsula), Lebanon (eastern Mediterranean), and Tunisia (North Africa), in particular with regard to the identification of the specific haplotypes that confer susceptibility to and protection from T1D in each community. Study subjects comprised unrelated Arab subjects from Bahrain (126 patients, 126 controls), Lebanon (78 patients, 111 controls), and Tunisia (50 patients, 50 controls). DRB1*030101-DQB1*0201 was found to be a locus that conferred susceptibility in three populations, while DRB1*040101-DQB1*0302 was found to be a locus that conferred susceptibility only in Tunisians and Bahrainis. The DRB1*100101-DQB1*050101 (Bahrainis) and DRB1*150101-DQB1*060101 (Lebanese) loci were found to be largely protective. Stayoussef et al. (2009) concluded that the contribution of HLA to T1D must be evaluated with regard to ethnic background.

Mahdi et al. (2009) investigated the association of human leukocyte antigens (HLA) class II alleles and haplotypes with the pathogenesis of acute chest syndrome (ACS) in a population of Bahraini sickle cell anemia (SCA) patients. The population study comprised 186 SCA patients, of whom 58 had documented ACS (new pulmonary infiltrate, fever, and other associated clinical events) and 128 with a negative history of ACS, serving as controls. Of the DRB1* and DQB1* alleles analyzed, only DRB1*130101 (Pc < 0.001) was found to be positively associated with ACS. DRB1*130101-DQB1*060101 haplotype was found to be more prevalent among ACS patients (P = 0.018), thus conferring disease susceptibility. Mahdi et al. (2009) concluded that specific HLA alleles and haplotypes may influence ACS risk in SCA patients, and specific HLA genotypes may be useful markers for identifying high-risk SCA ACS patients.

Bakr and El-Chenawy (1998) investigated the association between steroid-sensitive nephrotic syndrome (SSNS) of children and several HLA-DQ and DR alleles using DNA polymerase chain-reverse hybridization. Twenty-seven Egyptian children (16 males and 11 females, aged 3-8 years) with SSNS constituted the study population, of whom 20 were infrequent relapsers, and seven were frequent relapsers with or without steroid dependency. Seven patients (4 males and 3 females, aged 6-14 years) with steroid-resistant nephrotic syndrome (SRNS) were also studied. Results were compared with 121 healthy subjects for HLA-DRB1 and 59 subjects for DQB1 alleles. Bakr and El-Chenawy (1998) found that patients with SSNS have higher frequencies of DQB1*0601 (81.5% vs. 10.2% in controls) and its relative risks is significantly high (38.9, confidence interval [CI] =10.7 - 140.7), demonstrating a strong association of childhood SSNS and the DQB1*0601 allele. DRB1*01 was also found in high frequency among SSNS patients in this study. Bakr and El-Chenawy (1998) did not detect linkage disequilibrium between DQB1*0601 and DRB1*01, neither in the patients nor controls, denoting the independent role of each locus in the pathogenesis of the disease. Bakr and El-Chenawy (1998) did not find any significant differences in the distribution of DQB1* alleles between SRNS patients and controls and concluded that DQB1*0601 and DRB1*01 or closely associated unknown genes confer susceptibility to SSNS in Egyptian children. Bakr and El-Chenawy (1998) recommended that further studies are needed on a larger numbers of patients to confirm these results.

Sánchez-Velasco et al. (2001) studied major histocompatibility complex (MHC) class I and class II alleles in 100 unrelated adult Jordanians of both sexes from the capital Amman and in 46 individuals from the Jordan valley. Sánchez-Velasco et al. (2001) found the most frequent DQB1 alleles in Jordanians are DQB1*0201 (0.2000), DQB1*0302 (0.1783), and DQB1*0202 (0.1586). Sánchez-Velasco et al. (2001) also noted that three-loci haplotype heterogeneity was common and identified 38 HLA class II haplotypes in this population. The most frequent 3-loci haplotype observed in this population was DRB1*0401-DQA1*0301-DQB1*0302 (0.1793) followed by DRB1*0704-DQA1*0201-DQB1*0202 (0.1552). In addition, 220 different five-loci haplotypes with several unusual allelic combinations were observed, although many of them are pan-European haplotypes. The most frequent five-loci haplotype was found to be the A30-B7-DRB1*03-DQA1*0501-DQB1*0201 (0.0138). Since several Jordanian haplotypes were not found in the literature available at the time, Sánchez-Velasco et al. (2001) suggested that specific Jordanian haplotypes include: A31-B7-DRB1*04/07-DQA1*0301/0201-DQB1*0302/0202 haplotype (0.0103) and A1-B7-DRB1*07-DQA1*0201-DQB1*0202, A2-B7-DRB1*04-DQA1*0301-DQB1*0302, A11-B7-DRB1*07-DQA1*0201-DQB1*0201 haplotypes but at lower frequencies (0.007). Sánchez-Velasco et al. (2001) made a tree analysis of HLA class I and class II alleles for several Caucasian populations and calculated individual genetic distances. Haplotype frequencies, genetic distances, and dendrograms did not reveal great differences as compared with those in other Mediterranean countries and Western Europeans populations. These results led Sánchez-Velasco et al. (2001) to suggest that both HLA class I and class II polymorphisms (but especially the former) of the Jordanian population demonstrate considerable heterogeneity, which reflects ancient and recent admixture with neighboring populations, and important human migratory trends throughout the history.

Haider et al. (1999) determined the prevalence of human leukocyte antigen (HLA) DQB1 alleles in 78 Kuwaiti Arab children with insulin-dependent diabetes mellitus (IDDM) and in 57 normal healthy controls with similar ethnic background. Haider et al. (1999) also determined the prevalence of HLA-DQA1 alleles in the same population sample within this study. A significantly higher frequency of DQB1*0201 allele was found in IDDM cases compared to the controls (p<0.001). No significant difference was found in the prevalence of DQB1 alleles *0302, *0501, and *0602 between IDDM cases and the controls. In contrast, DQB1 alleles *0301, *0402, *0502, *0602, and *0603 were represented at a somewhat higher frequency in controls compared to the IDDM cohort. Analysis of HLA-DQBI/DQA1 haplotypes from IDDM cases and controls revealed a significantly high frequency of haplotype DQA1*0301/DQB1*0201 between Kuwaiti IDDM cases (49/78, 63%) and the controls (8/57, 14%).

Later, Haider et al. (2000) determined the prevalence of polymorphic amino acids at position 57 of the HLA DQB1 in Kuwaiti children with insulin-dependent diabetes mellitus (IDDM) and non-diabetic controls. A total of 34/55 (62%) IDDM children were found to be homozygous Ala/Ala and 19/55 (35%) were heterozygous with various combinations. Amongst the IDDM children with heterozygous genotype at codon 57 of HLA DQB1, 6/55 (11%) had Asp/Ala, 8/55 (15%) had Ala/Val, 4/55 (7%) had Ala/Ser and 1/55 had Asp/Val allelic combinations. When considered collectively, the non-aspartate (NA) alleles were represented in 87% of the IDDM cases and only 13% cases had Asp(57) allele in different heterozygous combinations, while none of the IDDM subjects had a homozygous Asp genotype. In non-diabetic controls, homozygous non-Asp (NA) alleles were represented in 44% subjects, 37% of the controls were heterozygous (NA/A) and 19% had a homozygous (A/A) genotype. These differences between the IDDM group and the control group were found to be statistically significant. Haider et al. (2000) concluded that the results of this study report one of the highest frequency of NA/NA residues at this locus compared with that from different world populations (e.g., Sardinians, Norwegians, US Caucasians, US Blacks, and Chinese).

Few years later, Haider and Zahid (2004) investigated the association between the HLA-DQB1 locus and schizophrenia in Kuwaiti Arabs, using polymerase chain reaction-sequence specific primers. The population study consisted of 81 unrelated Kuwaiti Arabs schizophrenia patients (61 men and 20 women, mean age: 41.97 years; range: 19-69 years) and 114 normal healthy control subjects (71 male and 43 female; mean age: 45.6 years) with similar ethnic background. A total of nine DQB1 alleles were identified in this Kuwaiti cohort. The most prevalent DQB1 alleles in Kuwaiti schizophrenia patients were found to be *0601 (28%), *0201 (23%) and *0501 (16%), respectively. However, no statistically significant difference was observed in the frequency of these alleles when compared with the controls. In the control group, most common DQB1 alleles were found to be *0201 (31%), *0601 (22%), *0501 (16%) and *0301 (13%), respectively. The DQB1*0602 allele, which has been negatively associated in African-Americans in previous reports, was not detected in the present Kuwaiti schizophrenia patients or controls. No significant difference was found in the distribution of HLA-DQB1 alleles between male and female schizophrenia subjects and similarly no gender-related association was detected when compared to the controls.

Allele frequencies of HLA Class II alleles, including HLA DQB1 alleles were studied in the Lebanese population by Khansa et al (2012), Almawi et al (2004a), Almawi et al (2004b), and Samaha et al (2003).  

Aimagambetova et al. 2019 conducted a retrospective study, which compared HLA-DPB1, HLA-DQB1, and HLA-DRB1 alleles and DPB1-DQB1-DRB1 haplotypes of 93 Lebanese women with idiopathic recurrent pregnancy loss (RPL) to a control group of 113 Lebanese women with two or more successful pregnancies, and no miscarriages. Allele frequencies of DRB1*04:01:01 and DRB1*08:01:01 were significantly higher in RPL cases than in control women. However, DRB1*07:01:01, DPB1*04:01:01, and DRB1*14:01:01  allele were observed to have significantly lower frequencies in women with RPL than in control women. Haplotype analysis revealed positive association of RPL with DPB1*04:01:01-DQB1*03:02:01-DRB1*04:01:01, whereas DPB1*04:01:01-DQB1*02:01:01-DRB1*07:01:01 was observed in lower frequencies among RPL cases suggesting an RPL-protective nature.

Stayoussef et al. (2009) investigated the association of HLA class II (DRB1 and DQB1) haplotypes with type 1 diabetes (T1D) in Bahrain (Arabian Peninsula), Lebanon (eastern Mediterranean), and Tunisia (North Africa), in particular with regard to the identification of the specific haplotypes that confer susceptibility to and protection from T1D in each community. Study subjects comprised unrelated Arab subjects from Bahrain (126 patients, 126 controls), Lebanon (78 patients, 111 controls), and Tunisia (50 patients, 50 controls). DRB1*030101-DQB1*0201 was found to be a locus that conferred susceptibility in three populations, while DRB1*040101-DQB1*0302 was found to be a locus that conferred susceptibility only in Tunisians and Bahrainis. The DRB1*100101-DQB1*050101 (Bahrainis) and DRB1*150101-DQB1*060101 (Lebanese) loci were found to be largely protective. Stayoussef et al. (2009) concluded that the contribution of HLA to T1D must be evaluated with regard to ethnic background.

Stayoussef et al. (2009) investigated the association of HLA class II (DRB1 and DQB1) haplotypes with type 1 diabetes (T1D) in Bahrain (Arabian Peninsula), Lebanon (eastern Mediterranean), and Tunisia (North Africa), in particular with regard to the identification of the specific haplotypes that confer susceptibility to and protection from T1D in each community. Study subjects comprised unrelated Arab subjects from Bahrain (126 patients, 126 controls), Lebanon (78 patients, 111 controls), and Tunisia (50 patients, 50 controls). DRB1*030101-DQB1*0201 was found to be a locus that conferred susceptibility in three populations, while DRB1*040101-DQB1*0302 was found to be a locus that conferred susceptibility only in Tunisians and Bahrainis. The DRB1*100101-DQB1*050101 (Bahrainis) and DRB1*150101-DQB1*060101 (Lebanese) loci were found to be largely protective. Stayoussef et al. (2009) concluded that the contribution of HLA to T1D must be evaluated with regard to ethnic background.

Al-Yafei et al. 2020 studied the distribution of HLA alleles in 77 unrelated Emiratis. The common HLA- DQB1 alleles identified among these subjects were DQB1*02:01:01 (16%), DQB1*02:02:01 (15%), DQB1*03:01:01 (12%), and DQB1*03:02:01 (12%).

Arnaiz-Villena et al. 2019 characterized HLA alleles in 52 blood donor volunteers from Abu Dhabi, UAE. HLA typing was carried out for HLA-A, HLA-B, HLA -C, HLA-DRB1, HLA-DQB1, and HLA-DQA1 alleles. Fourteen HLA-DQB1 alleles were identified in these subjects.

Creary et al. 2021 characterized HLA alleles and diversity across populations worldwide. One populaiton involved 52 Emirati individuals (104 chromosomes). HLA-A, HLA-C, HLA-B, HLA-DRB1, HLA-DRB3/4/5, HLA-DQA1, HLA-DQB1, HLA-DPA1, HLA-DPB1 alleles were typed in this population. 17 unique HLA-DQB1 alleles were identified in the Arab population.  

Tay et al. 2021 identified three HLA-DR4 haplotypes in seven children with type I diabetes from five Emirati families: HLA-DRB1∗04:01:01-DQB1∗03:02:01:01; HLA- DRB1∗04:02:01-DQB1∗03:02:01; and HLA-DRB1∗04:05:01-DQB1∗02:02:01:02. These haplotypes were previously associated with Type 1 Diabetes in Arabs. The study study additionally reported on HLA-DR4 and HLA-DR3 T1D risk haplotypes in the parents. Haplotypes HLA -A*26-B*08-DRB1*03 and HLA -C∗06-B∗50-DRB1∗03:01-DQ∗02 were also identified, previously associated with diabetes in North Indians. 

Alnaqbi et al. 2021 investigated the contribution of 20 HLA antigens to COVID19 severity in 115 Emirati patients. The study analyzed 20 HLA alleles involving HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1.HLA-B*51:01 and  HLA-A*26:01 was negatively associated with severity, whereas HLA-A*03:01, HLA-DRB1*15:01, and supertype B44 was positively associated with severity.

Al-Yafei et al. 2022 studied HLA-DRB1 and HLA-DQB1 alleles to understand its association with type 1 diabetes (T1D) in 149 Emirati T1D patients. Deviation from HWE (Hardy-Weinberg equilibrium) was noted at the DQB1 locus among patients because of the occurrence of five uncommon DQB1 genotypes. Five DQB1 alleles – DQB1*02:01, DQB1*03:02, DQB1*03:01, DQB1*05:01, and DQB1*06:01 – showed significant allelic differences in patients and control subjects. Positive association with T1D was observed with diplotypes DRB1*03:01~DQB1*02:01, DRB1*04:02~DQB1*03:02, and DRB1*04:05~DQB1*03:02, whereas negative association was observed with diplotype DRB1*16:02~DQB1*05:02.