@article {10805, title = {Investigation of the link between PROP taste perception and vegetables consumption using FAOSTAT data.}, journal = {Int J Food Sci Nutr}, year = {2018}, month = {2018 Oct 10}, pages = {1-7}, abstract = {

In this work we investigated, in populations located in Central Asia, the relationship between PROP taste perception and vegetables liking and consumption using FAOSTAT dataset. Collected data were analysed using distance matrices, Mantel test and Pearson correlation. Populations showing similar ability in tasting PROP bitterness are more similar as respect to vegetable consumption (r = 0.63, p-value = .05). Moreover, a significant negative correlation was found between the percentage of Non Taster (NT) in different countries and the percentage of vegetable consumption (r = -0.87, p-value = .02), while a significant positive correlation emerged between the percentage of Super Taster (ST) and the percentage of vegetable liking (r = 0.87, p-value = .02). In our work we showed that differences in bitter perception among populations contributes to differences in vegetable liking and vegetable consumption. More in detail, populations with higher percentage of ST consume more vegetables than population where the majority of individuals are NT.

}, issn = {1465-3478}, doi = {10.1080/09637486.2018.1519527}, author = {Mezzavilla, Massimo and Notarangelo, Michela and Concas, Maria Pina and Catamo, Eulalia and Gasparini, Paolo and Grillotti, Maria Gemma and Robino, Antonietta} } @article {10514, title = {Enrichment of low-frequency functional variants revealed by whole-genome sequencing of multiple isolated European populations.}, journal = {Nat Commun}, volume = {8}, year = {2017}, month = {2017 06 23}, pages = {15927}, abstract = {

The genetic features of isolated populations can boost power in complex-trait association studies, and an in-depth understanding of how their genetic variation has been shaped by their demographic history can help leverage these advantageous characteristics. Here, we perform a comprehensive investigation using 3,059 newly generated low-depth whole-genome sequences from eight European isolates and two matched general populations, together with published data from the 1000 Genomes Project and UK10K. Sequencing data give deeper and richer insights into population demography and genetic characteristics than genotype-chip data, distinguishing related populations more effectively and allowing their functional variants to be studied more fully. We demonstrate relaxation of purifying selection in the isolates, leading to enrichment of rare and low-frequency functional variants, using novel statistics, DVxy and SVxy. We also develop an isolation-index (Isx) that predicts the overall level of such key genetic characteristics and can thus help guide population choice in future complex-trait association studies.

}, keywords = {European Continental Ancestry Group, Gene Frequency, Genetic Variation, Genetics, Population, Genome, Human, Humans, Polymorphism, Single Nucleotide, Whole Genome Sequencing}, issn = {2041-1723}, doi = {10.1038/ncomms15927}, author = {Xue, Yali and Mezzavilla, Massimo and Haber, Marc and McCarthy, Shane and Chen, Yuan and Narasimhan, Vagheesh and Gilly, Arthur and Ayub, Qasim and Colonna, Vincenza and Southam, Lorraine and Finan, Christopher and Massaia, Andrea and Chheda, Himanshu and Palta, Priit and Ritchie, Graham and Asimit, Jennifer and Dedoussis, George and Gasparini, Paolo and Palotie, Aarno and Ripatti, Samuli and Soranzo, Nicole and Toniolo, Daniela and Wilson, James F and Durbin, Richard and Tyler-Smith, Chris and Zeggini, Eleftheria} } @article {8351, title = {Global diversity in the TAS2R38 bitter taste receptor: revisiting a classic evolutionary PROPosal.}, journal = {Sci Rep}, volume = {6}, year = {2016}, month = {2016}, pages = {25506}, abstract = {

The ability to taste phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) is a polymorphic trait mediated by the TAS2R38 bitter taste receptor gene. It has long been hypothesized that global genetic diversity at this locus evolved under pervasive pressures from balancing natural selection. However, recent high-resolution population genetic studies of TAS2Rs suggest that demographic events have played a critical role in the evolution of these genes. We here utilized the largest TAS2R38 database yet analyzed, consisting of 5,589 individuals from 105 populations, to examine natural selection, haplotype frequencies and linkage disequilibrium to estimate the effects of both selection and demography on contemporary patterns of variation at this locus. We found signs of an ancient balancing selection acting on this gene but no post Out-Of-Africa departures from neutrality, implying that the current observed patterns of variation can be predominantly explained by demographic, rather than selective events. In addition, we found signatures of ancient selective forces acting on different African TAS2R38 haplotypes. Collectively our results provide evidence for a relaxation of recent selective forces acting on this gene and a revised hypothesis for the origins of the present-day worldwide distribution of TAS2R38 haplotypes.

}, issn = {2045-2322}, doi = {10.1038/srep25506}, author = {Risso, Davide S and Mezzavilla, Massimo and Pagani, Luca and Robino, Antonietta and Morini, Gabriella and Tofanelli, Sergio and Carrai, Maura and Campa, Daniele and Barale, Roberto and Caradonna, Fabio and Gasparini, Paolo and Luiselli, Donata and Wooding, Stephen and Drayna, Dennis} } @article {8526, title = {A reference panel of 64,976 haplotypes for genotype imputation.}, journal = {Nat Genet}, year = {2016}, month = {2016 Aug 22}, abstract = {

We describe a reference panel of 64,976 human haplotypes at 39,235,157 SNPs constructed using whole-genome sequence data from 20 studies of predominantly European ancestry. Using this resource leads to accurate genotype imputation at minor allele frequencies as low as 0.1\% and a large increase in the number of SNPs tested in association studies, and it can help to discover and refine causal loci. We describe remote server resources that allow researchers to carry out imputation and phasing consistently and efficiently.

}, issn = {1546-1718}, doi = {10.1038/ng.3643}, author = {McCarthy, Shane and Das, Sayantan and Kretzschmar, Warren and Delaneau, Olivier and Wood, Andrew R and Teumer, Alexander and Kang, Hyun Min and Fuchsberger, Christian and Danecek, Petr and Sharp, Kevin and Luo, Yang and Sidore, Carlo and Kwong, Alan and Timpson, Nicholas and Koskinen, Seppo and Vrieze, Scott and Scott, Laura J and Zhang, He and Mahajan, Anubha and Veldink, Jan and Peters, Ulrike and Pato, Carlos and van Duijn, Cornelia M and Gillies, Christopher E and Gandin, Ilaria and Mezzavilla, Massimo and Gilly, Arthur and Cocca, Massimiliano and Traglia, Michela and Angius, Andrea and Barrett, Jeffrey C and Boomsma, Dorrett and Branham, Kari and Breen, Gerome and Brummett, Chad M and Busonero, Fabio and Campbell, Harry and Chan, Andrew and Chen, Sai and Chew, Emily and Collins, Francis S and Corbin, Laura J and Smith, George Davey and Dedoussis, George and D{\"o}rr, Marcus and Farmaki, Aliki-Eleni and Ferrucci, Luigi and Forer, Lukas and Fraser, Ross M and Gabriel, Stacey and Levy, Shawn and Groop, Leif and Harrison, Tabitha and Hattersley, Andrew and Holmen, Oddgeir L and Hveem, Kristian and Kretzler, Matthias and Lee, James C and McGue, Matt and Meitinger, Thomas and Melzer, David and Min, Josine L and Mohlke, Karen L and Vincent, John B and Nauck, Matthias and Nickerson, Deborah and Palotie, Aarno and Pato, Michele and Pirastu, Nicola and McInnis, Melvin and Richards, J Brent and Sala, Cinzia and Salomaa, Veikko and Schlessinger, David and Schoenherr, Sebastian and Slagboom, P Eline and Small, Kerrin and Spector, Timothy and Stambolian, Dwight and Tuke, Marcus and Tuomilehto, Jaakko and Van den Berg, Leonard H and van Rheenen, Wouter and V{\"o}lker, Uwe and Wijmenga, Cisca and Toniolo, Daniela and Zeggini, Eleftheria and Gasparini, Paolo and Sampson, Matthew G and Wilson, James F and Frayling, Timothy and de Bakker, Paul I W and Swertz, Morris A and McCarroll, Steven and Kooperberg, Charles and Dekker, Annelot and Altshuler, David and Willer, Cristen and Iacono, William and Ripatti, Samuli and Soranzo, Nicole and Walter, Klaudia and Swaroop, Anand and Cucca, Francesco and Anderson, Carl A and Myers, Richard M and Boehnke, Michael and McCarthy, Mark I and Durbin, Richard} } @article {8303, title = {Tracking of the origin of recurrent mutations of the BRCA1 and BRCA2 genes in the North-East of Italy and improved mutation analysis strategy.}, journal = {BMC Med Genet}, volume = {17}, year = {2016}, month = {2016}, pages = {11}, abstract = {

BACKGROUND: About 20 \% of hereditary breast cancers are caused by mutations in BRCA1 and BRCA2 genes. Since BRCA1 and BRCA2 mutations may be spread throughout the gene, genetic testing is usually performed by direct sequencing of entire coding regions. In some populations, especially if relatively isolated, a few number of recurrent mutations is reported, sometimes caused by founder effect.

METHODS: BRCA1 and BRCA2 screening for mutations was carried out on 1114 breast and/or ovarian cancer patients complying with the eligibility criteria for BRCA testing. Haplotype analysis was performed on the probands carrying recurrent mutations and their relatives, using two sets of microsatellite markers covering the BRCA1 (D17S588, D17S806, D17S902, D17S1325, D17S855, D17S1328, D17S800, and D17S250) and BRCA2 (D13S220, D13S267, D13S171, D13S1701, D13S1698, D13S260, D13S290, D13S1246) loci. The DMLE + 2.2 software was used to estimate the age of BRCA1 c.676delT and BRCA2 c.7806-2A > G. A multiplex PCR and two different primer extension assays were optimized and used for genotyping the recurrent mutations of the two genes.

RESULTS: In the time frame of almost 20 years of genetic testing, we have found that five BRCA1 and three BRCA2 mutations are recurrent in a substantial subset of carriers from North-East Italy and neighboring Istria, where they represent more than 50 \% of all mutations. Microsatellite analyses identified a common haplotype of different length for each mutation. Age estimation of BRCA1 c.676delT and BRCA2 c.7806-2A > G mutations revealed that they arose in the Friuli Venezia Giulia area about 86 and 94 generations ago, respectively. Suggestion of an association between BRCA2 c.7806-2A > G and risk of breast cancer in males has emerged. Finally, we developed a simple and efficient pre-screening test, performing an in-house primer extension SNaPshot{\textregistered} assay for the rapid identification of the eight recurrent mutations.

CONCLUSIONS: Proofs of common ancestry has been obtained for the eight recurrent mutations. The observed genotype-phenotype correlation and the proposed rapid mutation detection strategy could improve the clinical management of breast and ovarian patients in North-East of Italy and neighboring geographic areas.

}, keywords = {Adult, Aged, Alleles, BRCA1 Protein, BRCA2 Protein, Breast Neoplasms, Case-Control Studies, DNA Mutational Analysis, Female, Founder Effect, Genetic Testing, Genome-Wide Association Study, Genotyping Techniques, Haplotypes, Humans, Italy, Male, Microsatellite Repeats, Middle Aged, Mutation, Ovarian Neoplasms, Young Adult}, issn = {1471-2350}, doi = {10.1186/s12881-016-0274-6}, author = {Cini, Giulia and Mezzavilla, Massimo and Della Puppa, Lara and Cupelli, Elisa and Fornasin, Alessio and D{\textquoteright}Elia, Angela Valentina and Dolcetti, Riccardo and Damante, Giuseppe and Bertok, Sara and Miolo, Gianmaria and Maestro, Roberta and de Paoli, Paolo and Amoroso, Antonio and Viel, Alessandra} } @article {8297, title = {Understanding the role of personality and alexithymia in food preferences and PROP taste perception.}, journal = {Physiol Behav}, volume = {157}, year = {2016}, month = {2016 Apr 1}, pages = {72-8}, abstract = {

Taste perception and food preferences are influenced by a variety of factors, including personality characteristics. The aims of this study were to examine the role of personality characteristics, such as alexithymia (a personality construct characterized by inability to identify, describe, and work with one{\textquoteright}s own feelings), in: 1) taste responses to the bitter genetic taste-marker PROP and 2) food liking. We studied 649 healthy subjects residing in six genetically-isolated villages of Northeast Italy. Data on PROP taste responsiveness, food liking, personality characteristics and TAS2R28 genotypes were collected. Results showed that PROP non-tasters had higher alexithymia scores than PROP tasters. Moreover, the presence of alexithymia in heterozygous individuals for the rs1726886 polymorphism of the TAS2R38 gene was associated with a reduction in the perceived intensity of PROP. Finally, higher alexithymia scores were associated with liking of alcohol, sweets and fats/meats whereas lower alexithymia scores were related to liking of vegetables, condiments and strong cheeses, Measures of temperament, character, anxiety and depression were also related to food liking. Our findings suggest that: 1) alexithymia, in addition to the TAS2R38 polymorphism, may play a role in responsiveness to the aversive and bitter taste of PROP; and 2) alexithymia, in combination with other personality traits, may provide important insights for better understanding food liking.

}, issn = {1873-507X}, doi = {10.1016/j.physbeh.2016.01.022}, author = {Robino, Antonietta and Mezzavilla, Massimo and Pirastu, Nicola and La Bianca, Martina and Gasparini, Paolo and Carlino, Davide and Tepper, Beverly J} } @article {7775, title = {Analysis of functional variants reveals new candidate genes associated with alexithymia.}, journal = {Psychiatry Res}, volume = {227}, year = {2015}, month = {2015 Jun 30}, pages = {363-5}, abstract = {

In this study we explored the possible association between 36,915 functional variants and alexithymia, a personality trait characterized by the inability to identify and describe emotions and feelings. From our analysis, variants in the genes ABCB4, TP53AIP1, ARHGAP32 and TMEM88B were identified linked to the alexithymia phenotype.

}, keywords = {Adolescent, Adult, Affective Symptoms, Aged, Case-Control Studies, DNA-Binding Proteins, Emotions, Female, Humans, Male, Membrane Proteins, Middle Aged, P-Glycoproteins, Personality Inventory, Phenotype, Tumor Suppressor Proteins, Young Adult}, issn = {1872-7123}, doi = {10.1016/j.psychres.2015.03.018}, author = {Mezzavilla, Massimo and Ulivi, Sheila and Bianca, Martina La and Carlino, Davide and Gasparini, Paolo and Robino, Antonietta} } @article {7744, title = {Assessment of the olfactory function in Italian patients with type 3 von Willebrand disease caused by a homozygous 253 Kb deletion involving VWF and TMEM16B/ANO2.}, journal = {PLoS One}, volume = {10}, year = {2015}, month = {2015}, pages = {e0116483}, abstract = {

Type 3 Von Willebrand disease is an autosomal recessive disease caused by the virtual absence of the von Willebrand factor (VWF). A rare 253 kb gene deletion on chromosome 12, identified only in Italian and German families, involves both the VWF gene and the N-terminus of the neighbouring TMEM16B/ANO2 gene, a member of the family named transmembrane 16 (TMEM16) or anoctamin (ANO). TMEM16B is a calcium-activated chloride channel expressed in the olfactory epithelium. As a patient homozygous for the 253 kb deletion has been reported to have an olfactory impairment possibly related to the partial deletion of TMEM16B, we assessed the olfactory function in other patients using the University of Pennsylvania Smell Identification Test (UPSIT). The average UPSIT score of 4 homozygous patients was significantly lower than that of 5 healthy subjects with similar sex, age and education. However, 4 other members of the same family, 3 heterozygous for the deletion and 1 wild type, had a slightly reduced olfactory function indicating that socio-cultural or other factors were likely to be responsible for the observed difference. These results show that the ability to identify odorants of the homozygous patients for the deletion was not significantly different from that of the other members of the family, showing that the 253 kb deletion does not affect the olfactory performance. As other genes may compensate for the lack of TMEM16B, we identified some predicted functional partners from in silico studies of the protein-protein network of TMEM16B. Calculation of diversity for the corresponding genes for individuals of the 1000 Genomes Project showed that TMEM16B has the highest level of diversity among all genes of the network, indicating that TMEM16B may not be under purifying selection and suggesting that other genes in the network could compensate for its function for olfactory ability.

}, keywords = {Adult, Case-Control Studies, Female, Genetic Association Studies, Homozygote, Humans, Italy, Male, Membrane Proteins, Middle Aged, Olfactory Mucosa, Olfactory Perception, Sequence Deletion, Smell, von Willebrand Disease, Type 3, von Willebrand Factor, Young Adult}, issn = {1932-6203}, doi = {10.1371/journal.pone.0116483}, author = {Cenedese, Valentina and Mezzavilla, Massimo and Morgan, Anna and Marino, Renato and Ettorre, Cosimo Pietro and Margaglione, Maurizio and Gasparini, Paolo and Menini, Anna} } @article {8069, title = {Genetic evidence for an origin of the Armenians from Bronze Age mixing of multiple populations.}, journal = {Eur J Hum Genet}, year = {2015}, month = {2015 Oct 21}, abstract = {

The Armenians are a culturally isolated population who historically inhabited a region in the Near East bounded by the Mediterranean and Black seas and the Caucasus, but remain under-represented in genetic studies and have a complex history including a major geographic displacement during World War I. Here, we analyse genome-wide variation in 173 Armenians and compare them with 78 other worldwide populations. We find that Armenians form a distinctive cluster linking the Near East, Europe, and the Caucasus. We show that Armenian diversity can be explained by several mixtures of Eurasian populations that occurred between ~3000 and ~2000 bce, a period characterized by major population migrations after the domestication of the horse, appearance of chariots, and the rise of advanced civilizations in the Near East. However, genetic signals of population mixture cease after ~1200 bce when Bronze Age civilizations in the Eastern Mediterranean world suddenly and violently collapsed. Armenians have since remained isolated and genetic structure within the population developed ~500 years ago when Armenia was divided between the Ottomans and the Safavid Empire in Iran. Finally, we show that Armenians have higher genetic affinity to Neolithic Europeans than other present-day Near Easterners, and that 29\% of Armenian ancestry may originate from an ancestral population that is best represented by Neolithic Europeans.European Journal of Human Genetics advance online publication, 21 October 2015; doi:10.1038/ejhg.2015.206.

}, issn = {1476-5438}, doi = {10.1038/ejhg.2015.206}, author = {Haber, Marc and Mezzavilla, Massimo and Xue, Yali and Comas, David and Gasparini, Paolo and Zalloua, Pierre and Tyler-Smith, Chris} } @article {7771, title = {Increased rate of deleterious variants in long runs of homozygosity of an inbred population from Qatar.}, journal = {Hum Hered}, volume = {79}, year = {2015}, month = {2015}, pages = {14-9}, abstract = {

OBJECTIVE: The aim of this study is to evaluate the fraction of putatively deleterious variants within genomic runs of homozygosity (ROH) regions in an inbred and selected cohort of Qatari individuals.

METHODS: High-density SNP array analysis was performed in 36 individuals, and for 14 of them whole-exome sequencing (WES) was also carried out.

RESULTS: In all individuals, regions characterized by a high (hotspot) or low (coldspot) degree of homozygosity in all the analysed individuals were mapped, and the most frequent hotspot regions were selected. WES data were exploited to identify the single nucleotide variations (SNVs) harboured by genes located within both regions in each individual. Evolutionary conservation-based algorithms were employed to predict the potential deleteriousness of SNVs. The amount of in silico predicted deleterious SNVs was significantly different (p < 0.05) between homozygosity hotspot and coldspot regions.

CONCLUSION: Genes located within ROH hotspot regions contain a significant burden of predicted putatively deleterious variants compared to genes located outside these regions, suggesting inbreeding as a possible mechanism allowing an enrichment of putatively deleterious variants at the homozygous state.

}, keywords = {Cohort Studies, Consanguinity, Homozygote, Humans, Mutation, Polymorphism, Single Nucleotide, Qatar}, issn = {1423-0062}, doi = {10.1159/000371387}, author = {Mezzavilla, Massimo and Vozzi, Diego and Badii, Ramin and Alkowari, Moza Khalifa and Abdulhadi, Khalid and Girotto, Giorgia and Gasparini, Paolo} } @article {7719, title = {The Kalash genetic isolate: ancient divergence, drift, and selection.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 May 7}, pages = {775-83}, abstract = {

The Kalash represent an enigmatic isolated population of Indo-European speakers who have been living for centuries in the Hindu Kush mountain ranges of present-day Pakistan. Previous Y chromosome and mitochondrial DNA markers provided no support for their claimed Greek descent following Alexander III of Macedon{\textquoteright}s invasion of this region, and analysis of autosomal loci provided evidence of a strong genetic bottleneck. To understand their origins and demography further, we genotyped 23 unrelated Kalash samples on the Illumina HumanOmni2.5M-8 BeadChip and sequenced one male individual at high coverage on an Illumina HiSeq 2000. Comparison with published data from ancient hunter-gatherers and European farmers showed that the Kalash share genetic drift with the Paleolithic Siberian hunter-gatherers and might represent an extremely drifted ancient northern Eurasian population that also contributed to European and Near Eastern ancestry. Since the split from other South Asian populations, the Kalash have maintained a low long-term effective population size (2,319-2,603) and experienced no detectable gene flow from their geographic neighbors in Pakistan or from other extant Eurasian populations. The mean time of divergence between the Kalash and other populations currently residing in this region was estimated to be 11,800 (95\% confidence interval = 10,600-12,600) years ago, and thus they represent present-day descendants of some of the earliest migrants into the Indian sub-continent from West Asia.

}, keywords = {Asia, Asian Continental Ancestry Group, Chromosomes, Human, Y, Demography, DNA, Mitochondrial, European Continental Ancestry Group, Genetic Drift, Genetics, Population, Haplotypes, History, Ancient, Humans, Male, Pakistan, Phylogeny}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.03.012}, author = {Ayub, Qasim and Mezzavilla, Massimo and Pagani, Luca and Haber, Marc and Mohyuddin, Aisha and Khaliq, Shagufta and Mehdi, Syed Qasim and Tyler-Smith, Chris} } @article {8039, title = {Population genetic differentiation of height and body mass index across Europe.}, journal = {Nat Genet}, volume = {47}, year = {2015}, month = {2015 Nov}, pages = {1357-62}, abstract = {

Across-nation differences in the mean values for complex traits are common, but the reasons for these differences are unknown. Here we find that many independent loci contribute to population genetic differences in height and body mass index (BMI) in 9,416 individuals across 14 European countries. Using discovery data on over 250,000 individuals and unbiased effect size estimates from 17,500 sibling pairs, we estimate that 24\% (95\% credible interval (CI) = 9\%, 41\%) and 8\% (95\% CI = 4\%, 16\%) of the captured additive genetic variance for height and BMI, respectively, reflect population genetic differences. Population genetic divergence differed significantly from that in a null model (height, P < 3.94 {\texttimes} 10(-8); BMI, P < 5.95 {\texttimes} 10(-4)), and we find an among-population genetic correlation for tall and slender individuals (r = -0.80, 95\% CI = -0.95, -0.60), consistent with correlated selection for both phenotypes. Observed differences in height among populations reflected the predicted genetic means (r = 0.51; P < 0.001), but environmental differences across Europe masked genetic differentiation for BMI (P < 0.58).

}, issn = {1546-1718}, doi = {10.1038/ng.3401}, author = {Robinson, Matthew R and Hemani, Gibran and Medina-Gomez, Carolina and Mezzavilla, Massimo and Esko, T{\~o}nu and Shakhbazov, Konstantin and Powell, Joseph E and Vinkhuyzen, Anna and Berndt, Sonja I and Gustafsson, Stefan and Justice, Anne E and Kahali, Bratati and Locke, Adam E and Pers, Tune H and Vedantam, Sailaja and Wood, Andrew R and van Rheenen, Wouter and Andreassen, Ole A and Gasparini, Paolo and Metspalu, Andres and Berg, Leonard H van den and Veldink, Jan H and Rivadeneira, Fernando and Werge, Thomas M and Abecasis, Goncalo R and Boomsma, Dorret I and Chasman, Daniel I and de Geus, Eco J C and Frayling, Timothy M and Hirschhorn, Joel N and Hottenga, Jouke Jan and Ingelsson, Erik and Loos, Ruth J F and Magnusson, Patrik K E and Martin, Nicholas G and Montgomery, Grant W and North, Kari E and Pedersen, Nancy L and Spector, Timothy D and Speliotes, Elizabeth K and Goddard, Michael E and Yang, Jian and Visscher, Peter M} } @article {3575, title = {Consanguinity and hereditary hearing loss in Qatar.}, journal = {Hum Hered}, volume = {77}, year = {2014}, month = {2014}, pages = {175-82}, abstract = {

Qatar is a sovereign state located on the Eastern coast of the Arabian Peninsula in the Persian Gulf. Its native population consists of 3 major subgroups: people of Arabian origin or Bedouins, those from an Eastern or Persian ancestry and individuals with African admixture. Historically, all types of consanguineous marriages have been and still are common in the Qatari population, particularly among first and double-first cousins. Thus, there is a higher risk for most inherited diseases including hereditary hearing loss (HHL). In particular, a hearing loss prevalence of 5.2\% has been reported in Qatar, with parental consanguinity being more common among affected individuals as compared with unaffected ones. Our recent molecular results confirm a high homogeneity and level of inbreeding in Qatari HHL patients. Among all HHL genes, GJB2, the major player worldwide, accounts for a minor proportion of cases and at least 3 additional genes have been found to be mutated in Qatari patients. Interestingly, one gene, BDP1, has been described to cause HHL only in this country. These results point towards an unexpected level of genetic heterogeneity despite the high level of inbreeding. This review provides an up-to-date picture of HHL in Qatar and of the impact of consanguinity on this disease.

}, keywords = {Consanguinity, Hearing Loss, Homozygote, Humans, Inheritance Patterns, Pedigree, Prevalence, Principal Component Analysis, Qatar, Transcription Factor TFIIIB}, issn = {1423-0062}, doi = {10.1159/000360475}, author = {Girotto, Giorgia and Mezzavilla, Massimo and Abdulhadi, Khalid and Vuckovic, Dragana and Vozzi, Diego and Khalifa Alkowari, Moza and Gasparini, Paolo and Badii, Ramin} } @article {3622, title = {Genetic landscape of populations along the Silk Road: admixture and migration patterns.}, journal = {BMC Genet}, volume = {15}, year = {2014}, month = {2014}, pages = {131}, abstract = {

BACKGROUND: The ancient Silk Road has been a trading route between Europe and Central Asia from the 2(nd) century BCE to the 15(th) century CE. While most populations on this route have been characterized, the genetic background of others remains poorly understood, and little is known about past migration patterns. The scientific expedition "Marco Polo" has recently collected genetic and phenotypic data in six regions (Georgia, Armenia, Azerbaijan, Uzbekistan, Kazakhstan, Tajikistan) along the Silk Road to study the genetics of a number of phenotypes.

RESULTS: We characterized the genetic structure of these populations within a worldwide context. We observed a West-East subdivision albeit the existence of a genetic component shared within Central Asia and nearby populations from Europe and Near East. We observed a contribution of up to 50\% from Europe and Asia to most of the populations that have been analyzed. The contribution from Asia dates back to ~25 generations and is limited to the Eastern Silk Road. Time and direction of this contribution are consistent with the Mongolian expansion era.

CONCLUSIONS: We clarified the genetic structure of six populations from Central Asia and suggested a complex pattern of gene flow among them. We provided a map of migration events in time and space and we quantified exchanges among populations. Altogether these novel findings will support the future studies aimed at understanding the genetics of the phenotypes that have been collected during the Marco Polo campaign, they will provide insights into the history of these populations, and they will be useful to reconstruct the developments and events that have shaped modern Eurasians genomes.

}, keywords = {Asian Continental Ancestry Group, Commonwealth of Independent States, European Continental Ancestry Group, Gene Flow, Homozygote, Human Migration, Humans, Phenotype, Polymorphism, Single Nucleotide, Principal Component Analysis, Sequence Analysis, DNA}, issn = {1471-2156}, doi = {10.1186/s12863-014-0131-6}, author = {Mezzavilla, Massimo and Vozzi, Diego and Pirastu, Nicola and Girotto, Giorgia and d{\textquoteright}Adamo, Pio and Gasparini, Paolo and Colonna, Vincenza} } @article {3512, title = {Insight into genetic determinants of resting heart rate.}, journal = {Gene}, volume = {545}, year = {2014}, month = {2014 Jul 15}, pages = {170-4}, abstract = {

BACKGROUND: Recent studies suggested that resting heart rate (RHR) might be an independent predictor of cardiovascular mortality and morbidity. Nonetheless, the interrelation between RHR and cardiovascular diseases is not clear. In order to resolve this puzzle, the importance of genetic determinants of RHR has been recently suggested, but it needs to be further investigated.

OBJECTIVE: The aim of this study was to estimate the contribution of common genetic variations on RHR using Genome Wide Association Study.

METHODS: We performed a Genome Wide Association Study in an isolated population cohort of 1737 individuals, the Italian Network on Genetic Isolates - Friuli Venezia Giulia (INGI-FVG). Moreover, a haplotype analysis was performed. A regression tree analysis was run to highlight the effect of each haplotype combination on the phenotype.

RESULTS: A significant level of association (p<5 {\texttimes} 10(-8)) was detected for Single Nucleotide Polymorphisms (SNPs) in two genes expressed in the heart: MAML1 and CANX. Founding that the three different variants of the haplotype, which encompass both genes, yielded a phenotypic correlation. Indeed, a haplotype in homozygosity is significantly associated with the lower quartile of RHR (RHR <= 58 bpm). Moreover no significant association was found between cardiovascular risk factors and the different haplotype combinations.

CONCLUSION: Mastermind-like 1 and Calnexin were found to be associated with RHR. We demonstrated a relation between a haplotype and the lower quartile of RHR in our populations. Our findings highlight that genetic determinants of RHR may be implicated in determining cardiovascular diseases and could allow a better risk stratification.

}, keywords = {Calnexin, Cardiovascular Diseases, DNA-Binding Proteins, Female, Genome-Wide Association Study, Haplotypes, Heart Rate, Humans, Italy, Male, Middle Aged, Polymorphism, Single Nucleotide, Regression Analysis, Transcription Factors}, issn = {1879-0038}, doi = {10.1016/j.gene.2014.03.045}, author = {Mezzavilla, Massimo and Iorio, Annamaria and Bobbo, Marco and D{\textquoteright}Eustacchio, Angela and Merlo, Marco and Gasparini, Paolo and Ulivi, Sheila and Sinagra, Gianfranco} } @article {3507, title = {A population-based approach to study the impact of PROP perception on food liking in populations along the Silk Road.}, journal = {PLoS One}, volume = {9}, year = {2014}, month = {2014}, pages = {e91716}, abstract = {

Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3\%) and Armenia (39.0\%) and a higher frequency of non tasters in Georgia (50.9\%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes.

}, keywords = {Armenia, Azerbaijan, Food, Genetic Association Studies, Genotype, Haplotypes, Humans, Polymorphism, Single Nucleotide, Propylthiouracil, Receptors, G-Protein-Coupled, Tajikistan, Taste, Taste Perception, Uzbekistan}, issn = {1932-6203}, doi = {10.1371/journal.pone.0091716}, author = {Robino, Antonietta and Mezzavilla, Massimo and Pirastu, Nicola and Dognini, Maddalena and Tepper, Beverly J and Gasparini, Paolo} }