Analysis of Genetic Relationship Among 11 Iranian Ethnic Groups with Bayesian Multidimensional Scaling Using HLA Class II Data

Background: The key feature of Bayesian methods is their lack of dependence on defaults necessary for classical statistics. Because of the high volume of simulation, Bayesian methods have a high degree of accuracy. They are efficient in data mining and analyzing large volumes of data, and can be upgraded by entering new data. Objective: We used Bayesian multidimensional scaling (MDS) to analyze the genetic relationships among 11 Iranian ethnic groups based on HLA class II data. Method: Allele frequencies of three HLA loci from 816 unrelated individuals belonging to 11 Iranian ethnic groups were analyzed by Bayesian MDS using R and WinBUGS software. Results: like the results of correspondence analysis as a prototype of classical MDS analysis, the results of Bayesian MDS also showed Arabs from Famur, Balochis, Zoroastrians and Jews to be separate from other Iranian ethnic groups. Decreases stress in Bayesian MDS method compared to classical method revealed the accuracy of Bayesian MDS for HLA data analyses. Conclusion: This study reports the first application of Bayesian multidimensional scaling to HLA data analysis with Nei's DA genetic distances. Stress reduction in Bayesian MDS compared to classical MDS showed that the Bayesian approach can improve the accuracy of genetic data analysis

A new MEFV gene mutation in an Iranian patient with familial Mediterranean fever.

Familial mediterranean fever (FMF) is an inherited autoinflammatory disorder characterized by recurrent episodes of fever and painful inflammation involving the intra-abdominal organs, the lungs and the joints, which is highly prevalent in specific ethnic groups including the Iranians. We report a 12-year-old boy from Iran, with a clinical history of recurrent fever. Based on the suggestive clinical data, mutational analysis revealed the presence of the novel c.1945C>T heterozygous variant in exon 10, which leads to a leucine to phenylalanine change at position 649 of the protein. The mutation was inherited from the mother. This novel mutation lies in exon 10 of the MEFV gene, which encodes for a domain called B30.2-SPRY, located in the C-terminal region of the pyrin protein and contains the most frequent mutations associated with FMF. The present report expands the spectrum of MEFV gene mutations associated with FMF. The uniqueness of this study, compared with other published case reports, consists in the new mutation found in the MEFV gene. In fact, new mutations in this gene are of high interest, in order to better understand the role of this gene in autoinflammation

KIR gene content diversity in four Iranian populations

Killer cell immunoglobulin-like receptors (KIR) regulate natural killer cell response against infection and malignancy. KIR genes are variable in the number and type, thereby discriminating individuals and populations. Herein, we analyzed the KIR gene content diversity in four native populations of Iran. The KIR genomic diversity was comparable between Bakhtiari and Persian and displayed a balance of A and B KIR haplotypes, a trend reported in Caucasian and African populations. The KIR gene content profiles of Arab and Azeri were comparable and displayed a preponderance of B haplotypes, a scenario reported in the natives of America, India, and Australia. A majority of the B haplotype carriers of Azeri and Arab had a centromeric gene-cluster (KIR2DS2-2DL2-2DS3-2DL5). Remarkably, this cluster was totally absent from the American natives but occurred at highest frequencies in the natives of India and Australia in combination with another gene cluster at the telomeric region (KIR3DS1-2DL5-2DS5-2DS1). Therefore, despite having similar frequencies of B haplotypes, the occurrence of B haplotype-specific KIR genes, such as 2DL2, 2DL5, 3DS1, 2DS1, 2DS2, 2DS3, and 2DS5 in Azeri and Arab were substantially different from the natives of America, India, and Australia. In conclusion, each Iranian population exhibits distinct KIR gene content diversity, and the Indo-European KIR genetic signatures of the Iranians concur with geographic proximity, linguistic affinity, and human migrations

Origin and spread of human mitochondrial DNA haplogroup U7

Human mitochondrial DNA haplogroup U is among the initial maternal founders in Southwest Asia and Europe and one that best indicates matrilineal genetic continuity between late Pleistocene hunter-gatherer groups and present-day populations of Europe. While most haplogroup U subclades are older than 30 thousand years, the comparatively recent coalescence time of the extant variation of haplogroup U7 (~16–19 thousand years ago) suggests that its current distribution is the consequence of more recent dispersal events, despite its wide geographical range across Europe, the Near East and South Asia. Here we report 267 new U7 mitogenomes that – analysed alongside 100 published ones – enable us to discern at least two distinct temporal phases of dispersal, both of which most likely emanated from the Near East. The earlier one began prior to the Holocene (~11.5 thousand years ago) towards South Asia, while the later dispersal took place more recently towards Mediterranean Europe during the Neolithic (~8 thousand years ago). These findings imply that the carriers of haplogroup U7 spread to South Asia and Europe before the suggested Bronze Age expansion of Indo-European languages from the Pontic-Caspian Steppe region

The significance of HLA typing in transplantation

Although genetic admixture has recently occurred among different ethnic groups with the increased rates of migration to big cities, information about HLA allele distribution in different ethnic groups in Iran may still be helpful to improve the selection of transplantation donor candidates from certain ethnic groups which are genetically closer to the recipient. Because the data reported by Einollahi et al. reflect a large HLA disparity among Iranian kidney recipients, any improvement could play a small yet important role in organ transplantation

HLA-G: facts and fictions

Human leukocyte antigen (HLA)-G is a nonclassical MHC class I molecule with modulatory effects on NK and T cells. Unlike classical HLA class I molecules, HLA-G has seven isoforms, three of which are soluble. Soluble HLA-G molecules are reportedly able to transduce negative signals to immune cells after interacting with their corresponding receptors. The expression of these molecules plays significant roles in maternal tolerance against semi-allogenic fetuses. Overexpression of HLA-G in tumors and increased serum levels of soluble HLA-G have been reported in different malignancies, and these changes may be involved in tumoral immune evasion and cancer progression. To improve immune responses against tumor cells, the downmodulation of HLA-G by siRNA or blocking monoclonal antibodies can be helpful in cancer immunotherapy. Additionally, HLA-G can be considered a potential biomarker for the diagnosis and/or prognosis of certain cancers.  Although polymorphism of the HLA-G gene-coding region is more limited than in classical HLA class I, some genetic variations in regulatory regions of the gene control the expression level of this molecule. Furthermore, epigenetic factors such as infections may affect the expression of HLA-G in infection-related cancers

Awareness of Obesity-Related Cancers: A Complex Issue

Cancer rates are on the rise across the world, making the illness a public health crisis, particularly in developed countries where cancer has become a leading cause of death [...