7 research outputs found

    Chemometrics Methods for Specificity, Authenticity and Traceability Analysis of Olive Oils: Principles, Classifications and Applications

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    International audienceBackground. Olive oils (OOs) show high chemical variability due to several factors of genetic, environmental and anthropic types. Genetic and environmental factors are responsible for natural compositions and polymorphic diversification resulting in different varietal patterns and phenotypes. Anthropic factors, however, are at the origin of different blends' preparation leading to normative, labelled or adulterated commercial products. Control of complex OO samples requires their (i) characterization by specific markers; (ii) authentication by fingerprint patterns; and (iii) monitoring by traceability analysis.Methods. These quality control and management aims require the use of several multivariate statistical tools: specificity highlighting requires ordination methods; authentication checking calls for classification and pattern recognition methods; traceability analysis implies the use of network-based approaches able to separate or extract mixed information and memorized signals from complex matrices. Results. This chapter presents a review of different chemometrics methods applied for the control of OO variability from metabolic and physical-chemical measured characteristics. The different chemometrics methods are illustrated by different study cases on monovarietal and blended OO originated from different countries.Conclusion. Chemometrics tools offer multiple ways for quantitative evaluations and qualitative control of complex chemical variability of OO in relation to several intrinsic and extrinsic factors

    Chemometrics Methods for Specificity, Authenticity and Traceability Analysis of Olive Oils: Principles, Classifications and Applications

    No full text
    Background. Olive oils (OOs) show high chemical variability due to several factors of genetic, environmental and anthropic types. Genetic and environmental factors are responsible for natural compositions and polymorphic diversification resulting in different varietal patterns and phenotypes. Anthropic factors, however, are at the origin of different blends’ preparation leading to normative, labelled or adulterated commercial products. Control of complex OO samples requires their (i) characterization by specific markers; (ii) authentication by fingerprint patterns; and (iii) monitoring by traceability analysis. Methods. These quality control and management aims require the use of several multivariate statistical tools: specificity highlighting requires ordination methods; authentication checking calls for classification and pattern recognition methods; traceability analysis implies the use of network-based approaches able to separate or extract mixed information and memorized signals from complex matrices. Results. This chapter presents a review of different chemometrics methods applied for the control of OO variability from metabolic and physical-chemical measured characteristics. The different chemometrics methods are illustrated by different study cases on monovarietal and blended OO originated from different countries. Conclusion. Chemometrics tools offer multiple ways for quantitative evaluations and qualitative control of complex chemical variability of OO in relation to several intrinsic and extrinsic factors

    High frequency of W1327X mutation in glycogen storage disease type III patients from central Tunisia

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    International audienceGlycogen storage disease type III (GSD III) is an autosomal recessive disorder caused by the deficiency of glycogen debranching enzyme (AGL). It is characterized by hepatomegaly, progressive myopathy, cardiomyopathy and fasting hypoglycemia. Several mutations in AGL gene have been described in different populations. The W1327X mutation was reported in one Tunisian patient resident in Italy. We looked in this report to determine the frequency of W1327X mutation among Tunisian patients. The W1327X mutation was screening in 26 GSD III patients originated from various geographic locations in Tunisia. The sequence analysis revealed that among nine patients carried the W1327X mutation. Eight of them were from six unrelated families and they were originated from Mahdia (centre of Tunisia) suggesting the existence of a founder effect in this region. Taking into account historical migratory waves, screening for this mutation should be performed in priority for molecular diagnosis confirmation of GSD III in North African populations

    Specific aspects of consanguinity: some examples from the tunisian population.

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    International audienceLocated at the cross-road between Europe and Africa, Tunisia is a North African country of 11 million inhabitants. Throughout its history, it has been invaded by different ethnic groups. These historical events, and consanguinity, have impacted on the spectrum and frequency of genetic diseases in Tunisia. Investigations of Tunisian families have significantly contributed to elucidation of the genetic bases of rare disorders, providing an invaluable resource of cases due to particular familial structures (large family size, consanguinity and share of common ancestors). In the present study, we report on and review different aspects of consanguinity in the Tunisian population as a case study, representing several features common to neighboring or historically related countries in North Africa and the Middle East. Despite the educational, demographic and behavioral changes that have taken place during the last four decades, familial and geographical endogamy still exist at high frequencies, especially in rural areas. The health implications of consanguinity in Tunisian families include an increased risk of the expression of autosomal recessive diseases and particular phenotypic expressions. With new sequencing technologies, the investigation of consanguineous populations provides a unique opportunity to better evaluate the impact of consanguinity on the genome dynamic and on health, in addition to a better understanding of the genetic bases of diseases. © 2014 S. Karger AG, Basel

    History of settlement of villages from Central Tunisia by studying families sharing a common founder Glycogenosis type III mutation

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    International audienceGlycogen storage disease type III (GSD III; Cori disease; Forbes disease) is an autosomal recessive inherited metabolic disorder resulting from deficient glycogen debrancher enzyme activity in liver and muscle. In this study, we focused on a single AGL gene mutation p.W1327X in 16 Tunisian patients from rural area surrounding the region of Mahdia in Central Tunisia. This constitutes the largest pool of patients with this mutation ever described. This study was performed to trace the history of the patients' ancestries in a single region. After extraction of genomic DNA, exon 31 of AGL gene was sequenced. The patients were investigated for the hypervariable segment 1 of mitochondrial DNA and 17 Y-STR markers. We found that the p.W1327X mutation was a founder mutation in Tunisia Analysis of maternal lineages shows an admixture of autochthonous North African, sub-Saharan and a predominance of Eurasian haplogroups. Heterogeneity of maternal haplogroups indicates an ancient settlement. However, paternal gene flow was highly homogeneous and originates from the Near East. We hypothesize that the p.W1327X mutation was introduced into the Tunisian population probably by a recent migration event; then the mutation was fixed in a small region due to the high rate of consanguineous marriages and genetic drift. The screening for this mutation should be performed in priority for GSD III molecular diagnosis, for patients from the region of Mahdia and those from regions sharing the same settlement history

    Differential impact of consanguineous marriages on autosomal recessive diseases in Tunisia

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    International audienceObjectives Consanguinity is common in Tunisia. However, little information exists on its impact on recessive disorders. In this study, we evaluate the impact of consanguineous marriages on the occurrence of some specific autosomal recessive disorders and consider how other factors, such as population substructure and mutation frequency, may be of equal importance in disease prevalence. Methods Consanguinity profiles were retrospectively studied among 425 Tunisian patients suffering from autosomal recessive xeroderma pigmentosum, dystrophic epidermolysis bullosa, nonsyndromic retinitis pigmentosa, Gaucher disease, Fanconi anemia, glycogenosis type I, and ichthyosis, and compared to those of a healthy control sample. Results Consanguinity was observed in 341 cases (64.94%). Consanguinity rates per disease were 75.63, 63.64, 60.64, 61.29, 57.89, 73.33, and 51.28%, respectively. First-cousin marriages were the most common form of consanguinity (48.94%) with the percentages of 55.46, 45.46, 47.87, 48.39, 45.61, 56.66, and 35.90%, respectively. A very high level of geographic endogamy was also observed (93.92%), with the values by disease ranging between 75.86 and 96.64%. We observed an overall excess risk associated to consanguinity of nearly sevenfold which was proportional to the number of affected siblings and the frequency of disease allele in the family. Consanguinity was significantly associated with the first five cited diseases (odds ratio=24.41, 15.17, 7.5, 5.53, and 5.07, respectively). However, no meaningful effects were reported among the remaining diseases. Conclusions This study reveals a variation in the excess risk linked to consanguinity according to the type of disorder, suggesting the potential of cryptic population substructure to contribute to disease incidence in populations with complex social structure like Tunisia. It also emphasizes the role of other health and demographic aspects such as mutation frequency and reproductive replacement in diseases etiology. (c) 2015 Wiley Periodicals, Inc
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