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1.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(7): 858-861, 2024 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-38946373

RESUMO

OBJECTIVE: To explore the serological characteristics and genetic variant in a Chinese pedigree with Bw subtype. METHODS: A 32-year-old female proband who had undergone prenatal examination on December 10, 2020 at the 960th Hospital of the PLA Joint Logistics Support Force and five members from her pedigree were selected as the study subjects. Peripheral blood samples were collected and subjected to ABO blood group phenotyping with serological methods and ABO blood group genotyping with fluorescent PCR. Genetic testing and haplotype analysis were carried out by direct sequencing of the entire coding region of the ABO gene in the proband and cloned sequencing of exons 1-7. RESULTS: The blood type serology of the proband showed Bw, and her ABO blood type genotype determined by fluorescence PCR was B/O. The direct sequencing results showed that the proband had matched the ABO*O.01.01/ABO*B.01 genotype and carried a c.1A>G variant. Cloned sequencing has confirmed the c.1A>G variant to have occurred in the ABO*B.01 allele. Family analysis revealed that the mother of the proband had an O blood type, her husband had a B phenotype, and her three children had a normal B blood type. DNA sequencing showed that the two sons of the proband had a genotype of ABO*B.01 and c.1A>G/ABO*B.01. The daughter of the proband was ABO*O.01.01/ABO*B.01, whilst her mother was ABO*O.01.01/ABO *O.01.02. The novel c.1A>G variant sequence has been registered with the database with a number MZ076785 1. CONCLUSION: The novel c.1A>G variant of exon 1 of α- 1,3 galactose aminotransferase gene probably underlay the reduced expression of B antigen in this pedigree.


Assuntos
Sistema ABO de Grupos Sanguíneos , Povo Asiático , N-Acetilgalactosaminiltransferases , Linhagem , Adulto , Feminino , Humanos , Sistema ABO de Grupos Sanguíneos/genética , Alelos , Povo Asiático/genética , China , População do Leste Asiático , Genótipo , N-Acetilgalactosaminiltransferases/genética
2.
Sci Rep ; 14(1): 15058, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38956433

RESUMO

Since the COVID-19 pandemic, the diversity of clinical manifestations in patients has been a tremendous challenge. It seems that genetic variations, as one of the players, contribute to the variety of symptoms. Genome-wide association studies have demonstrated the influence of certain genomic regions on the disease prognosis. Particularly, a haplotype at 3p21.31 locus, inherited from Neanderthals, showed an association with COVID-19 severity. Despite several studies regarding this haplotype, some key variants are not sufficiently addressed. In the present study, we investigated the association of rs17713054 at 3p21.31 with COVID-19 severity. We analyzed the genotype of 251 Iranian COVID-19 patients (151 patients with asymptomatic to mild form as control and 100 patients with severe to critical symptoms without any comorbidities as case group) using the ARMS-PCR method. Results demonstrated that the A allele confers an almost twofold increased risk for COVID-19 severity (P value = 0.008). The AA genotype also raises the risk by more than 11 times following the recessive model (P value = 0.013). In conclusion, the A allele in rs17713054 was a risk allele in Iranian patients and was independently associated with COVID-19 severity. More studies are beneficial to confirm these findings in other populations and to develop strategies for risk assessment, prevention, and personalized medicine.


Assuntos
COVID-19 , Predisposição Genética para Doença , Homem de Neandertal , Polimorfismo de Nucleotídeo Único , SARS-CoV-2 , Índice de Gravidade de Doença , Humanos , COVID-19/genética , COVID-19/virologia , COVID-19/epidemiologia , Irã (Geográfico)/epidemiologia , Homem de Neandertal/genética , Masculino , Feminino , Pessoa de Meia-Idade , Animais , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Adulto , Haplótipos , Cromossomos Humanos Par 3/genética , Alelos , Estudo de Associação Genômica Ampla , Genótipo , Idoso
3.
BMC Genomics ; 25(1): 654, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38956457

RESUMO

BACKGROUND: Carcass weight (HCW) and marbling (MARB) are critical for meat quality and market value in beef cattle. In composite breeds like Brangus, which meld the genetics of Angus and Brahman, SNP-based analyses have illuminated some genetic influences on these traits, but they fall short in fully capturing the nuanced effects of breed of origin alleles (BOA) on these traits. Focus on the impacts of BOA on phenotypic features within Brangus populations can result in a more profound understanding of the specific influences of Angus and Brahman genetics. Moreover, the consideration of BOA becomes particularly significant when evaluating dominance effects contributing to heterosis in crossbred populations. BOA provides a more comprehensive measure of heterosis due to its ability to differentiate the distinct genetic contributions originating from each parent breed. This detailed understanding of genetic effects is essential for making informed breeding decisions to optimize the benefits of heterosis in composite breeds like Brangus. OBJECTIVE: This study aims to identify quantitative trait loci (QTL) influencing HCW and MARB by utilizing SNP and BOA information, incorporating additive, dominance, and overdominance effects within a multi-generational Brangus commercial herd. METHODS: We analyzed phenotypic data from 1,066 genotyped Brangus steers. BOA inference was performed using LAMP-LD software using Angus and Brahman reference sets. SNP-based and BOA-based GWAS were then conducted considering additive, dominance, and overdominance models. RESULTS: The study identified numerous QTLs for HCW and MARB. A notable QTL for HCW was associated to the SGCB gene, pivotal for muscle growth, and was identified solely in the BOA GWAS. Several BOA GWAS QTLs exhibited a dominance effect underscoring their importance in estimating heterosis. CONCLUSIONS: Our findings demonstrate that SNP-based methods may not detect all genetic variation affecting economically important traits in composite breeds. BOA inclusion in genomic evaluations is crucial for identifying genetic regions contributing to trait variation and for understanding the dominance value underpinning heterosis. By considering BOA, we gain a deeper understanding of genetic interactions and heterosis, which is integral to advancing breeding programs. The incorporation of BOA is recommended for comprehensive genomic evaluations to optimize trait improvements in crossbred cattle populations.


Assuntos
Cruzamento , Estudo de Associação Genômica Ampla , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Animais , Bovinos/genética , Genótipo , Vigor Híbrido , Carne , Alelos
4.
Mol Genet Genomic Med ; 12(7): e2480, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38958145

RESUMO

BACKGROUND: Pompe Disease (PD) is a metabolic myopathy caused by variants in the GAA gene, resulting in deficient enzymatic activity. We aimed to characterize the clinical features and related genetic variants in a series of Mexican patients. METHODS: We performed a retrospective study of clinical records of patients diagnosed with LOPD, IOPD or pseudodeficiency. RESULTS: Twenty-nine patients were included in the study, comprising these three forms. Overall, age of symptom onset was 0.1 to 43 years old. The most frequent variant identified was c.-32-13T>G, which was detected in 14 alleles. Among the 23 different variants identified in the GAA gene, 14 were classified as pathogenic, 5 were likely pathogenic, and 1 was a variant of uncertain significance. Two variants were inherited in cis arrangement and 2 were pseudodeficiency-related benign alleles. We identified two novel variants (c.1615 G>A and c.1076-20_1076-4delAAGTCGGCGTTGGCCTG). CONCLUSION: To the best of our knowledge, this series represent the largest phenotypic and genotypic characterization of patients with PD in Mexico. Patients within our series exhibited a combination of LOPD and IOPD associated variants, which may be related to genetic diversity within Mexican population. Further population-wide studies are required to better characterize the incidence of this disease in Mexican population.


Assuntos
Idade de Início , Doença de Depósito de Glicogênio Tipo II , Mutação , alfa-Glucosidases , Humanos , Doença de Depósito de Glicogênio Tipo II/genética , Doença de Depósito de Glicogênio Tipo II/patologia , Masculino , Feminino , Pré-Escolar , Criança , Adulto , alfa-Glucosidases/genética , Lactente , México/epidemiologia , Adolescente , Fenótipo , Estudos Retrospectivos , Estudos de Associação Genética , Alelos , Adulto Jovem
5.
Afr Health Sci ; 24(1): 307-312, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38962329

RESUMO

Introduction: Pharmacogenetic markers, such as the ATP Binding Cassette (ABCB1) and cytochrome P450 (CYP) 3A5 enzymes, play a crucial role in personalized medicine by influencing drug efficacy and toxicity based on individuals' or populations' genetic variations.This study aims to investigate the genetic polymorphisms of CYP3A5 (rs776746) and ABCB1 (rs1045642) in the West Algerian population and compare the genotypes and allelic distributions with those of various ethnic groups. Methods: The study involved 472 unrelated healthy subjects from the Western Algerian population. DNA genotyping was performed using TaqMan allelic discrimination assay. The variants in our population were compared to those in other ethnic groups available in the 1000 Genomes Project. Genotype and allele frequencies were calculated using the chi-square test and the Hardy-Weinberg equilibrium (HWE). Results: The minor allele frequencies were found to be 0.21 for CYP3A5 6986A and 0.34 for ABCB1 3435T. These frequencies were similar to those observed in North African populations, while notable differences were observed in comparison to certain Caucasian and African populations. Conclusion: The difference in the allelic and genotypic distribution of these polymorphisms emphasize the need for dose adjustments in drugs metabolized by CYP3A5 and transported by ABCB1 to optimize treatments outcomes.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP , Citocromo P-450 CYP3A , Frequência do Gene , Genótipo , Polimorfismo de Nucleotídeo Único , Humanos , Citocromo P-450 CYP3A/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Argélia , Masculino , Feminino , Adulto , Farmacogenética , Pessoa de Meia-Idade , População Negra/genética , Alelos , Adulto Jovem
6.
Zhonghua Xue Ye Xue Za Zhi ; 45(5): 453-461, 2024 May 14.
Artigo em Chinês | MEDLINE | ID: mdl-38964919

RESUMO

Objective: To investigate the impact of donor human leukocyte antigen (HLA) -Bw4 expression on natural killer (NK) cell reconstitution and transplant outcomes in recipients undergoing haploidentical hematopoietic stem cell transplantation (HSCT) from maternal or related donors without ex vivo T-cell depletion. Methods: This study prospectively enrolled 32 patients who received T-replete haploidentical HSCT from maternal or collateral donors (cohort 1) to evaluate the facilitating effect of donor HLA-Bw4 expression on NK cell reconstitution. Furthermore, a retrospective analysis was conducted on 278 patients who underwent T-replete haploidentical HSCT from maternal or collateral donors (cohort 2) to analyze the impact of donor HLA-Bw4 expression on HSCT outcomes. Thus, a comparison was made between the effects of donor HLA-Bw4 expression on HSCT outcomes in patients receiving or not receiving post-transplant cyclophosphamide (PT-Cy) conditioning. Results: Donors expressing HLA-Bw4 alleles facilitated NK cell reconstitution and functional recovery, which remained unaffected by PT-Cy. Donors with HLA-Bw4 expression were associated with reduced transplant-related mortality (TRM), particularly mortality related to infections. The use of PT-Cy did not impact the ability of donor HLA-Bw4 to decrease TRM. Conclusion: In haploidentical HSCT from maternal or related donors without ex vivo T-cell depletion, the presence of donor HLA-Bw4 expression promotes rapid NK cell reconstitution and functional recovery and is significantly associated with lower TRM, especially infection-related mortality. These findings underscore the clinical significance of donor HLA-Bw4 expression in patients who underwent HSCT. Hence, the consideration of donor HLA-Bw4 in recipient selection and HSCT strategies holds important clinical implications.


Assuntos
Antígenos HLA-B , Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais , Transplante Haploidêntico , Humanos , Células Matadoras Naturais/imunologia , Adulto , Feminino , Masculino , Transplante de Células-Tronco Hematopoéticas/métodos , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Antígenos HLA-B/genética , Estudos Retrospectivos , Estudos Prospectivos , Doadores de Tecidos , Criança , Alelos , Pré-Escolar , Condicionamento Pré-Transplante/métodos
7.
BMC Immunol ; 25(1): 40, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965465

RESUMO

BACKGROUND: Psoriasis has a global prevalence of 1-3%, with variations observed across different ethnic groups and geographical areas. Disease susceptibility and response to anti-tumor necrosis factor-α (TNFα) drugs suggest different genetic regulatory mechanisms which may include NLR family pyrin domain containing 3 (NLRP3) polymorphism. Evaluation of the NLRP3 gene polymorphism, the serum level of CRP and TNFα in psoriasis patients and assessment of the NLRP3 (rs10754558) gene polymorphism, CRP and TNFα with disease severity and their role as biomarkers for response to Methotrexate and Adalimumab in psoriasis. The study had a total of 75 patients diagnosed with psoriasis vulgaris, who were compared to a control group of 75 healthy individuals. RESULTS: There was a highly significant difference in NLRP3 genotypes and alleles distribution between psoriasis patients and controls (P = 0.002,0.004). The heterozygote genotype GC (OR = 3.67,95%CI:1.75-7.68, P = 0.0006), was linked with increased risk of psoriasis. Additionally, The GC genotype was significantly associated with nonresponse to psoriasis therapy (OR = 11.7,95%CI:3.24-42.28, P = 0.0002). Regarding serum CRP and TNFα levels, there was a highly statistically significant difference between psoriasis patients and controls (P < 0.0001), and there was also a highly statistically significant difference between responders and non-responders in psoriasis patients regarding PASI 50 (P < 0.0001). CONCLUSIONS: The NLRP3 (rs10754558) genotypes GC was associated with the severe form of psoriasis and with nonresponse to psoriasis medication. Therefore, NLRP3 (rs10754558) gene polymorphism is an important prognostic biomarker in psoriasis patients. The serum TNFα can be used as a predictor for response to therapy in psoriasis patients. More research for evaluation of role of the NLRP3 gene polymorphism in the genetic risks and treatment outcomes associated with psoriasis is still required.


Assuntos
Adalimumab , Metotrexato , Proteína 3 que Contém Domínio de Pirina da Família NLR , Polimorfismo de Nucleotídeo Único , Psoríase , Fator de Necrose Tumoral alfa , Humanos , Psoríase/genética , Psoríase/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Adalimumab/uso terapêutico , Metotrexato/uso terapêutico , Feminino , Fator de Necrose Tumoral alfa/genética , Masculino , Adulto , Pessoa de Meia-Idade , Genótipo , Predisposição Genética para Doença , Resultado do Tratamento , Proteína C-Reativa/metabolismo , Biomarcadores/sangue , Alelos , Índice de Gravidade de Doença , Frequência do Gene
8.
Theor Appl Genet ; 137(8): 177, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38972024

RESUMO

KEY MESSAGE: Underpinned natural variations and key genes associated with yield under different water regimes, and identified genomic signatures of genetic gain in the Indian wheat breeding program. A novel KASP marker for TKW under water stress was developed and validated. A comprehensive genome-wide association study was conducted on 300 spring wheat genotypes to elucidate the natural variations associated with grain yield and its eleven contributing traits under fully irrigated, restricted water, and simulated no water conditions. Utilizing the 35K Wheat Breeders' Array, we identified 1155 quantitative trait nucleotides (QTNs), with 207 QTNs exhibiting stability across diverse conditions. These QTNs were further delimited into 539 genomic regions using a genome-wide LD value of 3.0 Mbp, revealing pleiotropic control across traits and conditions. Sub-genome A was significantly associated with traits under irrigated conditions, while sub-genome B showed more QTNs under water stressed conditions. Favourable alleles with significantly associated QTNs were delineated, with a notable pyramiding effect for enhancing trait performance. Additionally, allele of only 921 QTNs significantly affected the population mean. Allele profiling highlighted C-306 as a most potential source of drought tolerance. Moreover, 762 genes overlapping significant QTNs were identified, narrowing down to 27 putative candidate genes overlapping 29 novel and functional SNPs expressing (≥ 0.5 tpm) relevance across various growth conditions. A new KASP assay was developed, targeting a gene TraesCS2A03G1123700 regulating thousand kernel weight under severe drought condition. Genomic selection models (GBLUP, BayesB, MxE, and R-Norm) demonstrated an average prediction accuracy of 0.06-0.58 across environments, indicating potential for trait selection. Retrospective analysis of the Indian wheat breeding program supported a genetic gain in GY at the rate of ca. 0.56% per breeding cycle, since 1960, supporting the identification of genomic signatures driving trait selection and genetic gain. These findings offer insight into improving the rate of genetic gain in wheat breeding programs globally.


Assuntos
Grão Comestível , Genótipo , Fenótipo , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum , Água , Triticum/genética , Triticum/crescimento & desenvolvimento , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Estudos de Associação Genética , Secas , Mapeamento Cromossômico/métodos , Desequilíbrio de Ligação , Alelos , Estudo de Associação Genômica Ampla , Índia
9.
Proc Biol Sci ; 291(2026): 20240693, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38981518

RESUMO

The evolution of separate sexes from cosexuality requires at least two mutations: a feminizing allele to cause female development and a masculinizing allele to cause male development. Classically, the double mutant is assumed to be sterile, which leads to two-factor sex determination where male and female sex chromosomes differ at two loci. However, several species appear to have one-factor sex determination where sexual development depends on variation at a single locus. We show that one-factor sex determination evolves when the double mutant develops as a male or a female. The feminizing allele fixes when the double mutant is male, and the masculinizing allele fixes when the double mutant is female. The other locus then gives XY or ZW sex determination based on dominance: for example, a dominant masculinizer becomes a Y chromosome. Although the resulting sex determination system differs, the conditions required for feminizers and masculinizers to spread are the same as in classical models, with the important difference that the two alleles do not need to be linked. Thus, we reveal alternative pathways for the evolution of sex determination and discuss how they can be distinguished using new data on the genetics of sex determination.


Assuntos
Mutação , Processos de Determinação Sexual , Masculino , Feminino , Animais , Cromossomos Sexuais , Evolução Biológica , Modelos Genéticos , Alelos , Ligação Genética
10.
Biochemistry (Mosc) ; 89(6): 1024-1030, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38981698

RESUMO

Tyrosine hydroxylase (TH) catalyzes hydroxylation of L-tyrosine to L-3,4-dihydroxyphenylalanine, the initial and rate-limiting step in the synthesis of dopamine, noradrenaline, and adrenaline. Mutations in the human TH gene are associated with hereditary motor disorders. The common C886T mutation identified in the mouse Th gene results in the R278H substitution in the enzyme molecule. We investigated the impact of this mutation on the TH activity in the mouse midbrain. The TH activity in the midbrain of Mus musculus castaneus (CAST) mice homozygous for the 886C allele was higher compared to C57BL/6 and DBA/2 mice homozygous for the 886T allele. Notably, this difference in the enzyme activity was not associated with changes in the Th gene mRNA levels and TH protein content. Analysis of the TH activity in the midbrain in mice from the F2 population obtained by crossbreeding of C57BL/6 and CAST mice revealed that the 886C allele is associated with a high TH activity. Moreover, this allele showed complete dominance over the 886T allele. However, the C886T mutation did not affect the levels of TH protein in the midbrain. These findings demonstrate that the C886T mutation is a major genetic factor determining the activity of TH in the midbrain of common laboratory mouse strains. Moreover, it represents the first common spontaneous mutation in the mouse Th gene whose influence on the enzyme activity has been demonstrated. These results will help to understand the role of TH in the development of adaptive and pathological behavior, elucidate molecular mechanisms regulating the activity of TH, and explore pharmacological agents for modulating its function.


Assuntos
Camundongos Endogâmicos C57BL , Tirosina 3-Mono-Oxigenase , Animais , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo , Camundongos , Mutação , Encéfalo/metabolismo , Camundongos Endogâmicos DBA , Mesencéfalo/metabolismo , Mesencéfalo/enzimologia , Masculino , Alelos
14.
PLoS One ; 19(7): e0303436, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38985786

RESUMO

Maize (Zea mays L.) C-type cytoplasmic male sterility (CMS-C) is a highly used CMS system for maize commercial hybrid seed production. Rf4 is the major dominant restorer gene for CMS-C. Inbreds were recently discovered which contain the restoring Rf4 allele yet are unable to restore fertility due to the lack of an additional gene required for Rf4's restoration. To find this additional gene, QTL mapping and positional cloning were performed using an inbred that contained Rf4 but was incapable of restoring CMS-C. The QTL was mapped to a 738-kb interval on chromosome 2, which contains a Pentatricopeptide Repeat (PPR) gene cluster. Allele content comparisons of the inbreds identified three potential candidate genes responsible for fertility restoration in CMS-C. Complementation via transformation of these three candidate genes showed that PPR153 (Zm00001eb114660) is required for Rf4 to restore fertility to tassels. The PPR153 sequence is present in B73 genome, but it is not capable of restoring CMS-C without Rf4. Analysis using NAM lines revealed that Rf4 requires the presence of PPR153 to restore CMS-C in diverse germplasms. This research uncovers a major CMS-C genetic restoration pathway and can be used for identifying inbreds suitable for maize hybrid production with CMS-C cytoplasm.


Assuntos
Infertilidade das Plantas , Locos de Características Quantitativas , Zea mays , Zea mays/genética , Infertilidade das Plantas/genética , Citoplasma/metabolismo , Citoplasma/genética , Mapeamento Cromossômico , Genes de Plantas , Proteínas de Plantas/genética , Alelos
15.
Sci Adv ; 10(28): eadk5462, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38985877

RESUMO

Adherens junction-associated protein 1 (AJAP1) has been implicated in brain diseases; however, a pathogenic mechanism has not been identified. AJAP1 is widely expressed in neurons and binds to γ-aminobutyric acid type B receptors (GBRs), which inhibit neurotransmitter release at most synapses in the brain. Here, we show that AJAP1 is selectively expressed in dendrites and trans-synaptically recruits GBRs to presynaptic sites of neurons expressing AJAP1. We have identified several monoallelic AJAP1 variants in individuals with epilepsy and/or neurodevelopmental disorders. Specifically, we show that the variant p.(W183C) lacks binding to GBRs, resulting in the inability to recruit them. Ultrastructural analysis revealed significantly decreased presynaptic GBR levels in Ajap1-/- and Ajap1W183C/+ mice. Consequently, these mice exhibited reduced GBR-mediated presynaptic inhibition at excitatory and inhibitory synapses, along with impaired synaptic plasticity. Our study reveals that AJAP1 enables the postsynaptic neuron to regulate the level of presynaptic GBR-mediated inhibition, supporting the clinical relevance of loss-of-function AJAP1 variants.


Assuntos
Neurotransmissores , Sinapses , Transmissão Sináptica , Animais , Humanos , Neurotransmissores/metabolismo , Camundongos , Sinapses/metabolismo , Masculino , Alelos , Feminino , Neurônios/metabolismo , Mutação com Perda de Função , Epilepsia/metabolismo , Epilepsia/genética , Epilepsia/patologia , Camundongos Knockout , Plasticidade Neuronal , Transtornos do Neurodesenvolvimento/metabolismo , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia
20.
HLA ; 104(1): e15574, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38993161

RESUMO

To investigate the potential relationship between HLA alleles and haplotypes and the age at diagnosis of type 1 diabetes (T1DAgeD) in an admixed Brazilian population. This nationwide study was conducted in public clinics across 12 Brazilian cities. We collected demographic and genetic data from 1,600 patients with T1D. DNA samples were utilised to determine genomic ancestry (GA) and perform HLA typings for DRB1, DQA1 and DQB1. We explored allele and haplotype frequencies and GA in patients grouped by T1DAgeD categories (<6 years, ≥6-<11 years, ≥11-<19 years and ≥19 years) through univariate and multivariate analyses and primary component analyses. Additionally, we considered self-reported colour-race and identified a familiar history of T1D in first-degree relatives. The homozygosity index for DRB1~DQA1~DQB1 haplotypes exhibited the highest variation among T1DAgeD groups, and the percentages of Sub-Saharan African and European ancestries showed opposite trends in principal component analysis (PCA) analyses. Regarding the association of alleles and haplotypes with T1DAgeD, risk alleles such as HLA-DQB1*03:02g, -DQA1*03:01g, -02:01g, DRB1*04:05g and -04:02g were more frequently observed in heterozygosity or homozygosity in T1D patients with an early disease onset. Conversely, alleles such as DRB1*07:01g, -13:03g, DQB1*06:02g and DQA1*02:01 were more prevalent in older T1D patients. The combination DR3/DR4.5 was significantly associated with early disease onset. However, gender, GA, familiar history of T1D and self-reported colour-race identity did not exhibit significant associations with the onset of T1D. It is worth noting that the very common risk haplotype DRB1*03:01g~DQA1*05:01g~DQB1*02:01g did not differentiate between T1DAgeD groups. In the admixed Brazilian population, the high-risk haplotype DRB1*04:05~DQA1*03:01~DQB1*03:02 was more prevalent in individuals diagnosed before 6 years of age. In contrast, the protective alleles DQA1*01:02g, DQB1*06:02g, DRB1*07:01g and DRB1*13:03g and haplotypes DRB1*13:03g~DQA1*05:01g~DQB1*03:01g and DRB1*16:02g~DQA1*01:02g~DQB1*05:02g were more frequently observed in patients diagnosed in adulthood. Notably, these associations were independent of factors such as sex, economic status, GA, familiar history of T1D and region of birth in Brazil. These alleles and haplotypes contribute to our understanding of the disease onset heterogeneity and may have implications for early interventions when detected in association with well-known genomic risk or protection factors for T1D.


Assuntos
Alelos , Diabetes Mellitus Tipo 1 , Frequência do Gene , Haplótipos , Humanos , Brasil/epidemiologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/diagnóstico , Masculino , Feminino , Criança , Adolescente , Adulto , Pré-Escolar , Adulto Jovem , Predisposição Genética para Doença , Cadeias HLA-DRB1/genética , Cadeias alfa de HLA-DQ/genética , Cadeias beta de HLA-DQ/genética , Idade de Início , Lactente , Pessoa de Meia-Idade
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