Phylogenetic relationships among 23 nonhuman primate (NHP) major histocompatibility complex class I chain-related gene (MIC) sequences, 54 confirmed human MICA alleles, and 16 human MICE alleles were constructed with methods of sequence analysis. Topology of the phylogenetic tree showed separation between NHP MICs and human MICs. For human MICs, the topology indicated monophyly for the MICB alleles, while MICA alleles were separated into two lineages, LI and LII. Of these, LI MICA alleles shared a common ancestry with gorilla (Ggo) MIC. One conservative amino acid difference and two nonconservative amino acid differences in the alpha3 domain were found between the MICA lineages. The nonconservative amino acid differences might imply structural and functional differences. Transmembrane (TM) trinucleotide-repeat variants were found to be specific to the MICA lineages such as A4, A9, and A10 to LI and A5 to LII. Variants such as A5.1 and A6 were commonly found in both MICA lineages. Based on these analyses, we postulate a polyphyletic origin for MICA alleles and their division into two lineages, LI and LII. As such, there would be 30 alleles in LI and 24 alleles in LII, thereby reducing the current level of polymorphism that exists, based on a presumed monophyletic origin. The lower degree of polymorphism in MICA would then be in line with the rest of the human major histocompatibility complex nonclassical class I genes.
Cynomolgus macaques (Macaca fascicularis) are quickly becoming a useful model for infectious disease and transplantation research. Even though cynomolgus macaques from different geographic regions are used for these studies, there has been limited characterization of full-length major histocompatibility complex (MHC) class I immunogenetics of distinct geographic populations. Here, we identified 48 MHC class I cDNA nucleotide sequences in eleven Indonesian cynomolgus macaques, including 41 novel Mafa-A and Mafa-B sequences. We found seven MHC class I sequences in Indonesian macaques that were identical to MHC class I sequences identified in Malaysian or Mauritian macaques. Sharing of nucleotide sequences between these geographically distinct populations is also consistent with the hypothesis that Indonesia was a source of the Mauritian macaque population. In addition, we found that the Indonesian cDNA sequence Mafa-B7601 is identical throughout its peptide binding domain to Mamu-B03, an allele that has been associated with control of Simian immunodeficiency virus (SIV) viremia in Indian rhesus macaques. Overall, a better understanding of the MHC class I alleles present in Indonesian cynomolgus macaques improves their value as a model for disease research, and it better defines the biogeography of cynomolgus macaques throughout Southeast Asia.
Genetic predisposition to carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) and toxic
epidermal necrolysis (TEN) had been reported in several Southeast Asian populations, but not in
Myanmar. Previous studies had so far reported more than 70% of CBZ-induced SJS/TEN cases
positive for HLA-B*15:02 allele.1-4 Myanmar, as the second largest country in Southeast Asia with a
population of 54.5 million, has high HLA-B*15:02 carrier frequency in its general population (27.3-
49.1%).5,6 We investigated the association of HLA-B alleles and CBZ-induced SJS/TEN in Myanmar
population. HLA-B*15:02 was detected in 3/3 (100%) of cases and 6/53 (11.3%) of tolerant controls,
and HLA-B*15:02 is significantly associated with CBZ-SJS/TEN in Myanmar population (OR 51.2,
95% CI 2.36-1106.95, p=0.003). (Copied from article)
Epilepsy is a common neurological disorder affecting approximately 50 million people worldwide. Antiepileptic drugs (AEDs) are commonly used to treat the disease depending, mainlyon the type of seizure. However, the useof AEDs mayalso lead to cutaneous adverse drug reactions (cADR) such as toxic epidermal necrolysis (TEN), Stevens-Johnsonsyndrome (SJS), exfoliative dermatitis (ED) and drug‐induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), which are unwanted comorbidities in epilepsy. It was first discoveredthat the HLA-B*15:02 allele was strongly associatedwith carbamazepine(CBZ)-induced SJS/TEN amongHan Chinese and this ledto the discovery of other HLAallelesand cytochrome P450 (CYP) genes that were significantly associatedwith various AED-inducedcADRsacross variouspopulations. This mini-reviewis an update on the latest findings ofthe involvement of various HLA alleles and CYP alleles in cADRs caused by CBZ, phenytoin (PHT), oxcarbazepine (OXC) and lamotrigine(LTG) in different case-control studies around the world. From our review, we found that CBZ-and PHT-induced cADRsweremore commonly reportedthan the other AEDs.Therefore,there were morerobust pharmacogenetics studies related to these AEDs. OXC-and LTG-induced cADRswereless commonly reported,and somore studies are needed to validate the reported association of the newer reported HLA alleles with theseAEDs. It is also importantto considerthe allelic frequency within a given population before concludingthe use of thesealleles as genetic markers to prevent AED-induced cADR. Overall, the current body of research pointto a combination of alleles as a better pharmacogenetic marker comparedto the use of a single gene as a genetic marker for AED-induced cADR.
A total of 271 Southeast Asia Indians from Peninsular Malaysia were genotyped for HLA-A, -B, -C, -DRB1, and -DQB1 loci using polymerase chain reaction sequence-specific oligonucleotide probe hybridization methods. In this report, HLA-B and HLA-DQB1 was in Hardy-Weinberg proportions (HWEP) (p > 0.05). We observed significant deviation from the HWEP for HLA-A (p