BackgroundSeveral studies have identified APOB as a candidate gene predisposing individuals to dyslipidemia. Polymorphisms including the signal peptide (rs11279109), codon 2488 XbaI (rs1042031), codon 3611 MspI (rs693), codon 4154 EcoRI (rs1801701) and the 3’ variable number of tandem repeats have been reported to be associated with dyslipidemia in several populations. With limited studies on Arabs, this study aimed to investigate the genetic association of APOB polymorphisms and assess the potential influence of minor and rare alleles on serum lipid levels in the Kuwaiti population.MethodsA total of 795 Kuwaiti subjects, documented with phenotypic data and fasting serum lipid levels, were genotyped for the five polymorphisms using PCR, PCR-RFLP and gene fragment analysis. Genotype and allele association with variation in serum lipid levels as well as haplotypes were analyzed using chi-square test, univariate and logistic regression analysis.ResultsAnalysis of the genotype and allele frequencies distribution revealed a significant positive association between the APOB signal peptide and 3611 MspI polymorphisms with increased levels of triglycerides (statistical power of 80%). Haplotype analysis further supported the findings by showing that carriers of haplotypes (IX−M−E+M) had significantly lower mean (SD) TG levels (0.86 ± 0.07) as compared to non-carriers (1.01 ± 0.02). Significance was also observed with regards to positive family history of hypercholesterolemia.ConclusionThe results imply a “protective role” for two alleles (rs11279109 and rs1801701) in which logistic regression analysis showed a significant half–fold decrease in the risk for heterozygotes of rs11279109 and an 8.8 fold decrease in the risk for homozygous M−M− of rs1801701 of having lower TG levels (<1.70 mmol/L) in individuals. This suggests that genetic interaction between various polymorphisms at different gene loci act in linkage disequilibrium to affect serum TG levels. Apo B genotyping may be a useful adjunct for the identification of individuals at risk of developing dyslipidemia in order to provide them with lifestyle modifications and/or pharmacological intervention to mitigate the effects of gene interaction and environmental influence.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-511X-13-157) contains supplementary material, which is available to authorized users.

The microphallid Maritrema eroliae parasitizes shore birds in marine ecosystems while its larval stages infect mud snails and crustacean hosts. Because it is difficult to morphologically distinguish between larvae of M. eroliae and other microphallids co-occurring in the same habitat, partial nucleotide sequences of the ribosomal DNA (rDNA), including the 28S and 18S in addition to complete sequences of ITS1 and ITS2, were scrutinized. This analysis was used to establish the snail-crab link in the life cycle of M. cf. eroliae . The rDNA 28S, 18S, and ITS sequences of metacercariae from the crab Xantho exaratus and sporocysts from the snail Clypeomorus bifasciata were compared. Sequence alignment demonstrated that the sporocyst and metacercaria may belong to M. eroliae and suggested a new second intermediate host for M. eroliae , the crab X. exaratus . The phylogenetic positions of the larval stages were determined by comparing the 28S, 18S, and ITS sequences with those of other trematodes available in GenBank. The phylogenetic trees confirmed the position of M. cf. eroliae within the Microphallidae and found it to be closely related to Maritrema heardi and Maritrema neomi. The present study represents the first molecular study correlating the larval stages in the life cycle of M. cf. eroliae using partial sequences of 28S and 18S in addition to complete ITS1 and ITS2 sequences. Furthermore, the sequences elucidated the evolutionary relationship of M. cf. eroliae to other microphallids.

No definite association was observed between consanguinity and the occurrence of facial clefts in Kuwait. General transmission models in the full data set showed no evidence of heterogeneity in the results between the Arab and nomad subsets.

The Middle East (ME) is an important crossroad where modern humans migrated 'out of Africa' and spread into Europe and Asia. After the initial peopling and long-term isolation leading to well-differentiated populations, the ME also had a crucial role in subsequent human migrations among Africa, Europe and Asia; thus, recent population admixture has been common in the ME. On the other hand, consanguinity, a well-known practice in the ME, often reduces genetic diversity and works in opposition to admixture. Here, we explored the degree to which admixture and consanguinity jointly affected genetic diversity in ME populations. Genome-wide single-nucleotide polymorphism data were generated in two representative ME populations (Arabian and Iranian), with comparisons made with populations worldwide. Our results revealed an overall higher genetic diversity in both ME populations relative to other non-African populations. We identified a much larger number of long runs of homozygosity in ME populations than in any other populations, which was most likely attributed to high levels of consanguineous marriages that significantly decreased both individual and population heterozygosity. Additionally, we were able to distinguish African, European and Asian ancestries in ME populations and quantify the impact of admixture and consanguinity with statistical approaches. Interestingly, genomic regions with significantly excessive ancestry from individual source populations are functionally enriched in olfactory pathways, which were suspected to be under natural selection. Our findings suggest that genetic admixture, consanguinity and natural selection have collectively shaped the genetic diversity of ME populations, which has important implications in both evolutionary studies and medical practices.

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