La porphyrie aiguë intermittente (PAI) est la plus fréquente des porphyries hépatiques aiguës. Elle est décrite comme une maladie autosomique dominante dont le trait génétique est estimé à 1/1675 en France avec une pénétrance faible et variable allant de 10% à 50% dans les familles connues de PAI. La PAI est due à des mutations réduisant le niveau d’activité de l’hydroxyméthylbilane-synthase (HMBS). Son déficit entraîne l’accumulation de précurseurs neurotoxiques responsables de la symptomatologie clinique. Dans le foie, la synthèse d’hème est contrôlée par l’enzyme ALA-Synthétase 1 (ALAS1) dont l’activité est régulée par un rétrocontrôle négatif par le produit final : l’hème. Le traitement consiste à freiner l’induction d’ALAS1 induit par la carence en hème, par l’administration d’hème exogène. Ce traitement de la crise aiguë est très efficace mais génère rapidement une dépendance physique avec apparition de crises récurrentes nécessitant l’administration chronique d’hème exogène. L’objectif principal de ce projet a été d’étudier les mécanismes physiopathologiques et génétiques liés à cette pathologie afin de traiter et conseiller au mieux les patients. Une partie du projet a consisté à explorer les facteurs génétiques modulateurs de la pénétrance de la maladie. Tout d’abord, une prévalence minimale du trait génétique dans la population générale a été estimée à 1/1299 permettant d’en déduire une pénétrance de l’ordre de 1% alors que celle dans les familles PAI suivies par le CFP est estimée à 22,9 %. Ensuite, concernant les facteurs pouvant expliquer cette différence, la présence d’une mutation type non-sens est plus fréquemment associée aux formes sévères et à une pénétrance plus élevée. De plus, les études de corrélation et d’héritabilité suggèrent plutôt une transmission de type oligogénique associée à des facteurs épigénétiques modulateurs de la pénétrance dont le facteur environnemental. Une autre partie a consisté à explorer les effets de l’administration d’hème exogène sur les patients et un modèle murin de PAI créé génétiquement. Chez l’homme, le traitement est associé à une augmentation des formes chroniques (1,7 % avant vs 7,5 % après l’introduction du celui-ci). Dans le modèle murin de PAI, les injections intrapéritonéales répétées induisent une augmentation paradoxale d’ALAS1 (3 fois), une augmentation de l’hème oxygénase 1 qui catabolise l’hème (HMOX1, 9 fois) ainsi que des voies de l’inflammation (analyse transcriptomique et protéomique hépatique) et une surcharge en fer. De plus, cette administration induit une altération des complexes de la chaine respiratoire mitochondriale responsable d’anomalies du métabolisme énergétique au niveau hépatique, cérébral et musculaire pouvant expliquer la symptomatologie neuroviscérale. En conclusion, ce travail a permis d’explorer les caractéristiques génétiques de la maladie (prévalence, pénétrance) en remettant en cause le mode de transmission autosomique dominant jusqu’ici admis, et d’explorer les mécanismes physiopathologiques associées à l’administration d’hème exogène faisant de cette thérapeutique un pharmakon / The biosynthesis of porphyrins is one of the most conserved pathways known. By associating different metals, porphyrins give rise to the "pigments of life". The formation of haem is accomplished by a sequence of eight dedicated enzymes encoded by different genes, some being active in ubiquitous as well as in erythroid isoforms. In humans, the genes for each of the haem synthetic enzymes may become the target of mutations that give rise to an impaired cellular enzyme activity called porphyrias. The acute porphyrias are characterized by attacks of neuropsychiatric symptoms, which may be due to a toxic surplus of the porphyrin precursor 5-aminolevulinic acid, or a consequence of a deficit of vital hemoproteins. Mutations of the gene encoding the third enzyme: hydroxymethylbilane synthase, are associated with the most frequent type of acute hepatic porphyria, acute intermittent porphyria. AIP is thought to display autosomal dominant inheritance with incomplete penetrance. In the classical form of AIP, HMBS activity is about 50% lower than normal in all tissues. These levels of activity in basal conditions are not sufficiently low to cause symptoms. However, factors increasing hepatic heme demand, resulting in an upregulation of hepatic aminolevulinate synthase (ALAS1, the first enzyme of the heme biosynthesis pathway), precipitate acute attacks. The treatment of the attack of AIP consists to repress ALAS1 and restores metabolic equilibrium. But this treatment leads side effects and dependency. The pathophysiological mechanism of the disease is partially known and difficult to explore because there is not an AIP model or prediction model of porphyrogenicity. We aimed to obtain further insight into the pathophysiological mechanism of AIP and into the genetic (prevalence and penetrance) of AIP, and the contribution of genetic factors to the variable clinical expression of HMBS mutations.We first calculated the penetrance of HMBS mutations in AIP patients seen at the French reference center for porphyria: 22.9%. We then used the Exome Variant Server (EVS) to estimate the prevalence of deleterious HMBS mutations in the general population: 1/1299; and the penetrance of the AIP genetic trait in France: 1%. Finally, we investigated further the genetic factors underlying the penetrance of AIP by analyzing genotype/phenotype correlations, and the pattern of familial correlations for the symptoms of the acute crises of AIP. Intrafamily correlation studies showed correlations to be strong overall and modulated by kinship and the era in which the person was living, demonstrating strong influences of genetic and environmental modifiers on inheritance suggesting that AIP inheritance does not follow the classical autosomal dominant model. Null alleles were associated with a more severe phenotype and a higher penetrance than for other mutant alleles.On the other hand, we explored the effect of heme administration. In human, the introduction of hemin into the pharmacopeia has coincided with a 4.4-fold increase in the prevalence of chronic patients. We show that repeated hemin infusions in mice trigger a high level heme oxygenase 1 response, induce a pro-oxidative iron accumulation, a complex pattern of liver inflammation with macrophage infiltration and an alteration of oxidative phosphorylation

<p>Microarray technology is a promising approach for the simultaneous analysis of multiple single nucleotide polymorphisms (SNPs), which are the most abundant form of genetic variation. In this thesis enzyme-assisted microarray-based methods were developed to improve the accuracy and genotype discrimination power of the current methods for SNP genotyping. The improved technology was applied for analysing recessively inherited disease mutations, for Y-chromosomal SNPs in a population study, for an evolutionary analysis of SNPs in flycatchers and for multiplexed quantitative determination of SNP-allele frequencies in pooled DNA samples. </p><p>A robust attachment chemistry for immobilising oligonucleotides on glass surface was established, based on an evaluation of eight covalent coupling methods. A four-colour fluorescence detection strategy, which enabled a multiplexed quantitative analysis for as little as 2% of a minority allele frequency in pooled samples was generated. </p><p>Twenty-five Y-chromosomal SNPs were screened in a collection of 300 samples from five Finno-Ugric-speaking populations using minisequencing on microarrays. In these populations six distinct haplotypes were defined by the six SNPs that were polymorphic. Data from five microsatellite markers was combined with the SNP data, revealing shared Y-chromosomal haplotypes between the Finns and the Saami, indicating, in accordance with earlier data, at least two founding Y-chromosomal lineages in these populations.</p><p>Database screening and subsequent validation of 125 potential SNPs in the highly repetitive type 1 interferon genes and genes coding for proteins in the interferon-related regulatory pathways revealed 25 informative SNPs in the Finnish and Swedish populations. These SNPs were included in a panel for microarray based genotyping that should find a variety of applications in genetic studies due to the important immunoregulatory functions of the IFN family.</p><p>The significance of sex-chromosome evolution on speciation was investigated in two naturally hybridising flycatcher species (N=459) by analysing a panel of 20 SNPs using minisequencing on microarrays. A strong selection against gene flow across the species boundary of sex-linked genes was observed, as well as a sex-chromosomal influence on male plumage characteristics that have previously been shown to reinforce isolation in these birds. The results suggest a major role for sex-chromosome-mediated isolation of the two flycatcher species.</p>

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-10-26T13:06:49Z No. of bitstreams: 2 Tese - Ricardo Goulart Rodovalho - 2017.pdf: 4249347 bytes, checksum: b731c79e9585351e61ca0e415749d4b1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-26T14:48:15Z (GMT) No. of bitstreams: 2 Tese - Ricardo Goulart Rodovalho - 2017.pdf: 4249347 bytes, checksum: b731c79e9585351e61ca0e415749d4b1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-26T14:48:15Z (GMT). No. of bitstreams: 2 Tese - Ricardo Goulart Rodovalho - 2017.pdf: 4249347 bytes, checksum: b731c79e9585351e61ca0e415749d4b1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-05 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The main scope of the current study was to develop a short tandem repeat (STR) multiplex system, made up of 22 highly informative loci, for application in forensic genetics. The system comprised of 21 polymorphic autosomal short tandem repeat loci, namely D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX, FGA, D2S441, D17S1301, D19S433, D18S853, D20S482 and D14S1434, and the amelogenin gene locus. Strategies were developed to overcome the challenges involved in creating a multiplex system. Based on the literature and available databases, STR loci were selected to obtain discriminatory markers, and followed specific criteria for this purpose. Primers were designed using the Primer3 software and the AutoDimer was used to evaluate potential interactions between them. The 21 selected STR loci were validated individually and jointly, both to assess their sensitivity and to test the efficiency of the multiplex system. Statistical analyses were based on the genetic data of 450 unrelated individuals living in the State of Goiás, thus allowing the establishment of the parameters necessary to use this system. A total of 239 alleles were detected for the 21 loci in the set, allowing for a probability of identity of 4.23 x 10-25 to be obtained. The combined power of discrimination was 0.999999999999999999999999 and the combined power of exclusion was 0.99999. Upon complete validation of the entire system, this multiplex assay was considered to be a powerful tool for application in human identification by DNA analysis. / O escopo principal do atual estudo foi o desenvolvimento de um sistema multiplex de loci STR, composto por 22 loci altamente informativos para aplicação em genética forense. O sistema compreendeu 21 loci STRs polimórficos autossômicos, a seguir D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX, FGA, D2S441, D17S1301, D19S433, D18S853, D20S482 e D14S1434, e o locus do gene da amelogenina. As estratégias foram desenvolvidas para superar os desafios envolvidos na criação de um sistema multiplex. Com base na literatura e nas bases de dados disponíveis, os loci STRs foram selecionados para obter marcadores discriminatórios e seguiram critérios específicos para esse fim. Os primers foram projetados usando o software Primer3, e o AutoDimer foi usado para avaliar potenciais interações entre eles. Os 22 loci selecionados foram validados individualmente e em conjunto, tanto para avaliar sua sensibilidade quanto para testar a eficiência do sistema multiplex. As análises estatísticas foram baseadas nos dados genéticos de 450 indivíduos não relacionados e residentes no estado de Goiás, permitindo assim estabelecer os parâmetros necessários para a utilização do sistema. Um total de 239 alelos foram detectados para os 21 loci do conjunto, permitindo obter uma probabilidade de identidade de 4,23 x 10-25. O poder combinado de discriminação foi 0,999999999999999999999999 e o poder combinado de exclusão foi 0,99999. Após a validação completa de todo o sistema, este ensaio de multiplex foi considerado uma ferramenta poderosa para aplicação na identificação humana pela análise do DNA.

Genetic variations in taste receptor genes play a notable role in human taste perception and food preferences and intake, which may affect nutritional and health status. Understanding how genetic variations in taste receptor genes influence food perception, preferences, and intake can play an important role in designing effective interventions to improve the quality of peoples' nutrition and minimize the risk of diet-related diseases such as obesity. The objective of this study was to investigate single nucleotide polymorphisms (SNPs) of umami taste receptor gene TAS1R1 and GRM4 and sweet taste receptor gene TAS1R3 and percentage of body fat mass (BF%) among young adults. 833 young adults aged 18-31 years old were enrolled in a cross-sectional study. Umami and sweet taste receptor genotypes were determined and analyzed. A strong association was observed between the allele frequencies of sweet taste receptor gene TAS1R3 for SNPs rs307355 and rs35744813 and BMI, and between the same SNPs rs307355 and rs35744813 and BF%. In addition, the allele frequencies of SNP rs2499729 were significantly related to the likelihood of having obesity based on BMI classification. However, there was no association between the allele frequencies of the SNPs of the umami taste receptor genes; TAS1R1 for rs34160967 and BMI or BF%. The results of this study also indicated association in total energy intake and the percentage of energy from carbohydrates, protein, and fat intake between the alleles of the sweet receptor gene TAS1R3 for rs307355 and 35744813. Furthermore, a notable association was also detected in the percentage of energy from fat intake among the alleles of the umami receptors gene TAS1R1 rs34160967, and a significant relation in the percentage of energy from carbohydrates and protein intake between the different genotype polymorphisms of the umami receptor GRM4 gene for rs2499729.

No description available.

Zusammenfassung Viele Untersuchungen deuten darauf hin, dass das Surfaktantprotein A (SP-A) sowohl an der Regulation des Surfaktanthaushalts als auch als unspezifisches Opsonin an der Abwehr von Pathogenen in der Lunge beteiligt ist. Zahlreiche Polymorphismen kennzeichnen die Gene der Proteinuntereinheiten SP-A1 und 2. Die häufigste Aminosäuresubstitution Val50Leu befindet sich in der kollagenartigen Domäne, die an den Kollektinrezeptor der Phagozyten bindet. Weitere existieren in der an der Bindung an Lipopolysaccharide, Surfaktantbestandteile und Rezeptoren auf Pneumozyten beteiligten Kohlehydraterkennungsregion (CRD) der globulären Domäne. Träger des schwach exprimierten Wildtypallels 1a0 des SP-A2-Gens haben ein erhöhtes Risiko, am Atemnotsyndrom des Neugeborenen (RDS) zu erkranken. Bei der Alveolarproteinose akkumulieren die hydrophilen Surfaktantproteine A und D in den Alveolen. In der vorliegenden Arbeit wurde eine nested PCR zur isolierten Amplifikation beider SP-A-Gene etabliert. 31 Patienten mit Verdacht auf einen Surfaktantproteindefekt wurden auf neue Restriktionsfragmentlängenpolymorphismen (RFLP) im SP-A1-Gen untersucht. Der in einer Familie konstante NcoI-Polymorphismus 1162C>T in Codon 39 und der NdeI-Polymorphismus 3138T>C in Codon 184 wurden mit einer Allelfrequenz von etwa 11 % detektiert. Die Sequenzen der entsprechenden Allele wurden kloniert. Bei 14 Patienten mit idiopathischer Alveolarproteinose, therapierefraktärem Surfaktantmangel oder rezidivierender Pneumonie wurden die SP-A-Gene sequenziert. Der bisher nur SP-A1 zugeschriebene Aminosäureaustausch Val50Leu wurde als Substitution 1220G>C bei zwei Patienten im SP-A2-Gen nachgewiesen. Drei Patienten mit Alveolarproteinose waren homozygot für die Substitution Gln223Lys in der CRD des SP-A2. Bei einem Patienten handelte es sich möglicherweise um eine somatische Mutation der Leukozyten-DNA im Rahmen einer Leukämie mit sekundärer Alveolarproteinose. Ein anderer war heterozygoter Träger des seltenen Allels 6a4 mit der Aminosäuresubstitution Arg219Trp in der CRD des SP-A1 und hatte die Alveolarproteinose erst im Erwachsenenalter entwickelt. Der dritte war homozygoter Träger des sehr seltenen Allels 1a3 des SP-A2 und verstarb im Alter von 6 Wochen an konnataler Alveolarproteinose (CAP), ohne dass ein bekannter Defekt des SP-B- oder des GM-CSF-Rezeptorgens vorlag. Die SSCP-Analyse konnte allelische Varianten als Einzelstrangkonformationspolymorphismen unterscheiden, war jedoch als Suchtest in heterozygoten Proben zu unspezifisch. Der hohe Gehalt an Polymorphismusinformation (PIC) macht den SP-A-Genort sftp1 zu einem nützlichen Marker bei der Untersuchung der Surfaktantproteine und anderer auf Chromosom 10 lokalisierter Gene. / Abstract Many studies give evidence of the role of surfactant protein A (SP-A) in the regulation of surfactant homeostasis and the defence from pathogens in the lung by opsonisation. The genes for the two protein subunits SP-A1 and SP-A2 are characterised by numerous polymorphisms. The most frequently substituted amino acid Val50Leu is located within the collagen-like region, which is recognised by the collectin-receptor on phagocytes. Further amino acids are substituted in the globular region, which is involved into the binding to lipopolysaccharides, surfactant particles, and receptors on pneumocytes by its carbohydrate recognition domain (CRD). Individuals carrying the weakly expressed wild-type allele 1a0 of SP-A2 have an increased risk of developing the respiratory distress syndrome (RDS) of the new-born. Alveolar proteinosis is a disease with accumulation of the hydrophilic surfactant proteins SP-A and SP-D in the alveoli. In this study a nested PCR for separate amplification of the two SP-A genes has been established. 31 patients with suspected deficiency of a surfactant protein has been investigated for new restriction fragment length polymorphisms (RFLP) in the SP-A1 gene. The NcoI-polymorphism 1162C>T in codon 39, which was constantly inherited in one family, and the NdeI-polymorphism 3138T>C in codon 184 have been detected with an allele frequency of around 11 %. The DNA sequences of these alleles have been cloned. In 14 patients suffering from idiopathic alveolar proteinosis, therapy-refractory surfactant deficiency, or recurrent pneumonia the SP-A genes have been sequenced. The substituted amino acid Val50Leu, which was previously considered exclusively in SP-A1, has been detected in SP-A2 in two patients. Three patients with alveolar proteinosis proved to be homozygous for the substitution Gln223Lys within the CRD of SP-A2. One of these patients might have a somatic mutation in the DNA of his leucocytes, with alveolar proteinosis developing secondary to his leukaemia. Another one developed alveolar proteinosis as an adult and was heterozygous for the rare allele 6a4 which includes the substituted amino acid Arg219Trp in the CRD of SP-A1. The third one proved to be homozygous for the very rare allele 1a3 of SP-A2 and died at 6 weeks of age from congenital alveolar proteinosis (CAP) without having one of the known mutations responsible for this condition within the genes for surfactant protein B (SP-B) or the GM-CSF receptor protein. The allelic variants could be differentiated by single strand conformation polymorphism but the SSCP-analysis was not enough specific for the screening of heterozygous DNA. Due to its high polymorphism information content (PIC), the SP-A gene locus sftp1 is a useful genetic marker for the analysis of the surfactant proteins and other genes located on chromosome 10.

Submitted by admin tede (tede@pucgoias.edu.br) on 2018-06-19T18:56:40Z No. of bitstreams: 1 NAYARA LOPES DE SOUZA.pdf: 749306 bytes, checksum: 81981ca0392819388d97ce062f438484 (MD5) / Made available in DSpace on 2018-06-19T18:56:40Z (GMT). No. of bitstreams: 1 NAYARA LOPES DE SOUZA.pdf: 749306 bytes, checksum: 81981ca0392819388d97ce062f438484 (MD5) Previous issue date: 2018-03-13 / Database construction with allelic and genotypic frequencies of STRs has a significant impact on the processes of human identification of different populations. Brazil already has a database of allelic and genotype frequencies of the markers of the autosomal chromosomes and markers of the Y chromosome. However, there are few studies of allelic and genotype frequencies for markers of the X chromosome. These markers have a high discrimination power and have a high rate of resolution in forensic situations, and genetic linkage analysis. The objective of this study was to estimate, in a Brazilian population, allelic and genotypic frequencies, observed in 12 STR markers of the X chromosome, aiming the consolidation of a population database with applications in genetic linkage research. For this, 1,190 genetic profiles of individuals not genetically related and submitted to genetic linkage tests from all regions of Brazil were analyzed. The samples were genotyped using the Investigator® Argus X-12 system (Qiagen, Germany). Capillary electrophoresis was performed on ABI 3500 gene analyzer. Allele frequencies were analyzed using Genetix 4.05.2 and Alerquin ® software and Hardy-Weinberg equilibrium was analyzed using GenePop 4.1.3 and Alerquin® software. Allele and genotype frequencies were obtained for the 12 STRs of the X chromosome, the 15 allele of the DXS7423 locus was the most frequent, presenting a value corresponding to 0.40 in the female sex and 0.44 in the male sex. However, several alleles in all markers presented frequencies lower than 0.01, being considered rare in the population. No Deviation of Hardy-Weinberg Equilibrium was observed in the marker set when analyzed simultaneously. The DXS10135 locus had a higher expected heterozygosity than the other loci for females, with a frequency of 0.9445. The observed heterozygosity also presented variation regarding the values found, from 0.9160 to 0.6803. Thus, the Argus X-12 system was informative in the Brazilian population and, therefore, a useful tool in forensic practice, particularly in inconclusive cases and in cases of kinship involving high complexity. / A construção de banco de dados com frequências alélicas e genotípicas de marcadores STRs tem um impacto significativo nos processos de identificação humana de diferentes populações. O Brasil já possui banco de dados de frequências alélicas e genotípicas dos marcadores dos cromossomos autossômicos e marcadores do cromossomo Y. No entanto, existem poucos estudos de frequências alélicas e genotípicas para os marcadores do cromossomo X. Estes marcadores possuem um alto poder de discriminação e apresentam alta taxa de resolutividade em situações forenses, e análises de vínculo genético. O objetivo deste estudo foi estimar, em uma amostra populacional brasileira, frequências alélicas e genotípicas, observadas em 12 marcadores STR do cromossomo X visando a consolidação de um banco de dados populacional com aplicações em investigação de vínculo genético. Para isso, foram analisados 1.190 perfis genéticos de indivíduos não relacionados geneticamente e submetidos a testes de investigações de vínculo genético, provenientes de todas as regiões do Brasil. As amostras foram genotipadas utilizando o sistema Investigator® Argus X-12 (Qiagen, Germany). A eletroforese capilar foi realizada no analisador genético ABI 3500. As frequências alélicas e genotípicas foram analisadas com auxílio do software Genetix 4.05.2 e Alerquin®, o equilíbro de Hardy-Weinberg foi analisado através do software GenePop 4.1.3. As frequências alélicas e genotípicas foram obtidas para os 12 marcadores STRs do cromossomo X, o alelo 15 do locus DXS7423 foi o mais frequente, apresentando valor correspondente a 0,40 no sexo feminino e 0,44 no sexo masculino. No entanto, diversos alelos em todos os marcadores apresentaram frequências inferiores a 0,01, sendo considerados raros na população. Não foi observado desvio do Equilíbrio de Hardy- Weinberg no conjunto de marcadores quando analisados simultaneamente. O locus DXS10135 apresentou uma heterozigosidade esperada maior em relação aos outros loci para os indivíduos do sexo feminino, com frequência 0,9445. A heterozigosidade observada também apresentou variação quanto aos valores encontrados, de 0,9160 a 0,6803. Sendo assim, o sistema Argus X-12 apresentou-se informativo na população brasileira, sendo, portanto, uma ferramenta útil na prática forense, particularmente em casos inconclusivos e em casos de parentesco envolvendo alta complexidade.

The aim of the present study was to evaluate the power of discrimination and genetic (diversity) parameters in the Y chromosome extended haploytpe markers in populations of Tanzania for forensic and populations studies. Eleven Y chromosome extended haplotype markers were selected for this study, these includes Minimal haplotypes markers i.e. DYS19, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS389I/II and two additional markers DYS438 and DYS439. Six populations of Tanzania were investigated under this study. These populations were selected based on the language family categories / Niger Congo (Kuria and Sukuma), Nilo Saharan (Luo and Maasai) and Afro Asiatic (Iraqw and Alagwa).

Background. Familial Amyloidosis with Polyneuropathy (FAP) is an autosomal dominantly inherited systemic amyloid disease. The disease is caused by mutations in the transthyretin (TTR) gene, where close to 100 different amyloidogenic mutations have been identified. FAP is found worldwide, but endemic areas with a high frequency of patients are found in Portugal, Japan and northern Sweden. Cases from these endemic areas all share the same TTR c.148G&gt;A, p.V50M ("V30M") mutation, but the phenotype of the disease varies between the areas, and also within the endemic areas. The mean onset of the disease is two decades earlier in Portugal and Japan compared to Sweden, but late as well as early age at onset cases occur within all the populations. Interestingly, the different populations all display a maternal anticipation, where an earlier onset is observed for those individuals who inherit the trait from their mother. Since substantial variation in the phenotype is observed for different populations, epigenetic/genetic and/or environmental factors must exert a significant impact on the penetrance of the disease. Amyloid formation is caused by conformational changes of proteins, which facilitates their assembly into fibrils, amyloid. Oxidative stress can mediate conformational changes of proteins and since the mitochondria regulate oxidative processes within the cell, mitochondrial function may affect amyloid formation. The mitochondrial DNA is a non-nuclear DNA, which is entirely maternally inherited, and therefore could be related to the observed maternal anticipation of the disease. In addition, differences within the surrounding regions of the TTR gene may have an impact on the transcription of the gene and thereby on the expression of the different alleles. Material and methods. DNA from early and late onset V30M cases and from non-carriers (the latter utilised as controls) from Swedish, French, Japanese and Portuguese populations were analysed. In addition, DNA from healthy Swedish V30M carriers was analysed. Conventional analytical methods were employed, such as PCR, sequencing and genotyping. Conventional statistical methods used were t-test, Chi-squared test and maximum likelihood. Results. The study of V30M carrier frequency in two counties (Lycksele and Skellefteå) within the Swedish endemic area revealed a carrier frequency of 2.14% and 2.54%, respectively. The mitochondrial haplogroup analysis showed that in populations with generally late onset (French and Swedish), the haplogroup distribution of late onset cases resembled that of the controls derived from the same area, whereas haplogroup distribution for early onset patients was significantly different. The most pronounced difference was for the rare haplogroup K, of which early onset cases had a higher frequency than the controls. Analysis of the Portuguese population, with predominantly early onset, showed that haplogroup distribution for early onset cases were similar to the Portuguese control group, which had a different distribution than the Swedish control group. By analysis of pedigrees from Swedish and Portuguese patients it could be shown that mitochondrial genetic variation entirely could explain maternal anticipation in the Portuguese patients, whereas for Swedish patients, an additional parent of origin effect is present. Our analysis of the TTR gene disclosed a polymorphism (rs62093482) in the 3'UTR region of the Swedish patients. This polymorphism was found in all V30M carriers, irrespective of symptoms. In addition, homozygous TTR V30M carriers were homozygous also for the polymorphism. Since Swedish patients share a common founder this polymorphism thus is localised on the V30M allele. This polymorphism was found in only 4% of the Swedish controls. French controls showed the same frequency, but none of the French V30M patients displayed the polymorphism. In the Japanese population the polymorphism was not present at all. Interestingly, this polymorphism generates a potential binding site for microRNA and thereby possibly could down-regulate the expression of the mutated TTR allele. Conclusions. The carrier frequency in the endemic area is remarkably high, above 2% in the Lycksele and Skellefteå areas. The prevailing haplogroup distributions in the different endemic areas are consistent between the general population and the patient group with the predominant phenotype of that area. Mitochondrial genetic differences may explain maternal anticipation in Portuguese patients, and have an influence in Swedish patients. A polymorphism in the 3'UTR regulatory region of the mutated TTR allele is found in all Swedish patients. This polymorphism may down-regulate TTR V30M expression and thereby contribute to the late onset of the disease noted in the Swedish population.

The aim of the present study was to evaluate the power of discrimination and genetic (diversity) parameters in the Y chromosome extended haploytpe markers in populations of Tanzania for forensic and populations studies. Eleven Y chromosome extended haplotype markers were selected for this study, these includes Minimal haplotypes markers i.e. DYS19, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS389I/II and two additional markers DYS438 and DYS439. Six populations of Tanzania were investigated under this study. These populations were selected based on the language family categories / Niger Congo (Kuria and Sukuma), Nilo Saharan (Luo and Maasai) and Afro Asiatic (Iraqw and Alagwa).