RESUMO
BACKGROUND: Xeroderma pigmentosum (XP) patients present a high risk of developing skin cancer and other complications at an early age. This disease is characterized by mutations in the genes related to the DNA repair system. OBJECTIVES: To describe the clinical and molecular findings in a cohort of 32 Brazilian individuals who received a clinical diagnosis of XP. METHODS: Twenty-seven families were screened for germline variants in eight XP-related genes. RESULTS: All patients (N = 32) were diagnosed with bi-allelic germline pathogenic or potentially pathogenic variants, including nine variants previously undescribed. The c.2251-1G>C XPC pathogenic variant, reported as the founder mutation in Comorian and Pakistani patients, was observed in 15 cases in homozygous or compound heterozygous. Seven homozygous patients for POLH/XPV variants developed their symptoms by an average age of 7.7 years. ERCC2/XPD, DDB2/XPE and ERCC5/XPG variants were found in a few patients. Aside from melanoma and non-melanoma skin tumours, a set of patients developed skin sebaceous carcinoma, leiomyosarcoma, angiosarcoma, mucoepidermoid carcinoma, gastric adenocarcinoma and serous ovarian carcinoma. CONCLUSIONS: We reported a high frequency of XPC variants in 32 XP Brazilian patients. Nine new variants in XP-related genes, unexpected non-skin cancer lesions and an anticipation of the clinical manifestation in POLH/XPV cases were also described.
Assuntos
Xeroderma Pigmentoso , Brasil , Criança , Reparo do DNA , Mutação em Linhagem Germinativa , Homozigoto , Humanos , Mutação , Xeroderma Pigmentoso/genética , Proteína Grupo D do Xeroderma Pigmentoso/genéticaRESUMO
Polymorphisms of hormone receptor genes have been linked to modifications in reproductive factors and to an increased risk of breast cancer (BC). In the present study, we have determined the allelic and genotypic frequencies of the ERα-397 PvuII C/T, ERα-351 XbaI A/G and PGR PROGINS polymorphisms and investigated their relationship with mammographic density, body mass index (BMI) and other risk factors for BC. A consecutive and unselected sample of 750 Brazilian BC-unaffected women enrolled in a mammography screening program was recruited. The distribution of PGR PROGINS genotypic frequencies was 72.5, 25.5 and 2.0% for A1A1, A1A2 and A2A2, respectively, which was equivalent to that encountered in other studies with healthy women. The distribution of ERα genotypes was: ERα-397 PvuII C/T: 32.3% TT, 47.5% TC, and 20.2% CC; ERα-351 XbaI A/G: 46.3% AA, 41.7% AG and 12.0% GG. ERα haplotypes were 53.5% PX, 14.3% Px, 0.3% pX, and 32.0% px. These were significantly different from most previously published reports worldwide (P < 0.05). Overall, the PGR PROGINS genotypes A2A2 and A1A2 were associated with fatty and moderately fatty breast tissue. The same genotypes were also associated with a high BMI in postmenopausal women. In addition, the ERα-351 XbaI GG genotype was associated with menarche ≥12 years (P = 0.02). ERα and PGR polymorphisms have a phenotypic effect and may play an important role in BC risk determination. Finally, if confirmed in BC patients, these associations could have important implications for mammographic screening and strategies and may be helpful to identify women at higher risk for the disease.
Assuntos
Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/genética , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Receptor alfa de Estrogênio/genética , Predisposição Genética para Doença , Polimorfismo Genético/genética , Receptores de Progesterona/genética , Índice de Massa Corporal , Brasil , Neoplasias da Mama/diagnóstico , Frequência do Gene , Genótipo , Glândulas Mamárias Humanas/anormalidades , Prevalência , Fatores de RiscoRESUMO
p53 has a crucial role in human fertility by regulating the expression of leukemia inhibitory factor (LIF), a secreted cytokine critical for blastocyst implantation. To examine whether TP53 polymorphisms may be involved with in vitro fertilization (IVF) failure and endometriosis (END), we have assessed the associations between TP53 polymorphism in intron 2 (PIN2; G/C, intron 2), PIN3 (one (N, non-duplicated) or two (D, duplicated) repeats of a 16-bp motif, intron 3) and polymorphism in exon 4 (PEX4; C/G, p.P72R, exon 4) in 98 women with END and 115 women with post-IVF failure. In addition, 134 fertile women and 300 women unselected with respect to fertility-related features were assessed. TP53 polymorphisms and haplotypes were identified by amplification refractory mutation system polymerase chain reaction. TP53 PIN3 and PEX4 were associated with both END (P=0.042 and P=0.007, respectively) and IVF (P=0.004 and P=0.009, respectively) when compared with women both selected and unselected for fertility-related features. Haplotypes D-C and N-C were related to higher risk for END (P=0.002, P=0.001, respectively) and failure of IVF (P=0.018 and P=0.002, respectively) when compared with the Fertile group. These results support that specific TP53 haplotypes are associated with an increased risk of END-associated infertility and with post-IVF failure.
Assuntos
Endometriose/complicações , Infertilidade Feminina/etiologia , Proteína Supressora de Tumor p53/genética , Adulto , Feminino , Fertilização in vitro , Frequência do Gene , Genótipo , Haplótipos , Humanos , Íntrons , Desequilíbrio de Ligação , Pessoa de Meia-Idade , Polimorfismo Genético , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Cândido Godói (CG) is a small town in South Brazil, which has the highest prevalence of twin births in Brazil. Recently, a number of studies have shown that p53 plays an important role in reproduction through blastocyst implantation and intra utero embryo survival. Thus, gene polymorphisms in the p53 pathway were investigated in this population. METHODS: Single nucleotide polymorphisms from five genes in the p53 pathway were investigated, as well as background characteristics of 42 mothers of twins (cases) and 101 mothers of singletons (controls), all residents from CG. RESULTS: Mothers of twins have higher number of pregnancies and higher frequencies of P72 allele at TP53 and T allele at MDM4 genes compared with controls. Logistic regression shows that both TP53 and number of pregnancies maintained their association with twinning (P =0.004 and P =0.002, respectively), with TP53 having a higher odds ratio than number of pregnancies (2.73 versus 1.70, respectively). No interactive effect between TP53 and MDM4 (P =0.966) is observed. As expected, mothers of twins have three times more cases of cancer in their first-degree relatives than control mothers (P =0.011). CONCLUSIONS: Our results suggest that the P72 allele of TP53 is a strong risk factor for twinning in CG, while the number of pregnancies and the T allele at MDM4 may represent weaker risk factors. These two alleles are associated with infertility, but the anti-apoptotic effect of low levels of p53 in general, and of the P72 allele in particular, may play a role after implantation, enhancing the chance for a double pregnancy to succeed to term.
Assuntos
Fertilidade/genética , Fertilidade/fisiologia , Genes p53 , Proteína Supressora de Tumor p53/genética , Gêmeos/genética , Adulto , Alelos , Blastocisto , Brasil , Estudos de Casos e Controles , Implantação do Embrião , Feminino , Humanos , Infertilidade , Razão de Chances , Polimorfismo Genético , Gravidez , Prevalência , Fatores de RiscoRESUMO
Polymorphisms of hormone receptor genes have been linked to modifications in reproductive factors and to an increased risk of breast cancer (BC). In the present study, we have determined the allelic and genotypic frequencies of the ERα-397 PvuII C/T, ERα-351 XbaI A/G and PGR PROGINS polymorphisms and investigated their relationship with mammographic density, body mass index (BMI) and other risk factors for BC. A consecutive and unselected sample of 750 Brazilian BC-unaffected women enrolled in a mammography screening program was recruited. The distribution of PGR PROGINS genotypic frequencies was 72.5, 25.5 and 2.0% for A1A1, A1A2 and A2A2, respectively, which was equivalent to that encountered in other studies with healthy women. The distribution of ERα genotypes was: ERα-397 PvuII C/T: 32.3% TT, 47.5% TC, and 20.2% CC; ERα-351 XbaI A/G: 46.3% AA, 41.7% AG and 12.0% GG. ERα haplotypes were 53.5% PX, 14.3% Px, 0.3% pX, and 32.0% px. These were significantly different from most previously published reports worldwide (P < 0.05). Overall, the PGR PROGINS genotypes A2A2 and A1A2 were associated with fatty and moderately fatty breast tissue. The same genotypes were also associated with a high BMI in postmenopausal women. In addition, the ERα-351 XbaI GG genotype was associated with menarche ≥ 12 years (P = 0.02). ERα and PGR polymorphisms have a phenotypic effect and may play an important role in BC risk determination. Finally, if confirmed in BC patients, these associations could have important implications for mammographic screening and strategies and may be helpful to identify women at higher risk for the disease.
Assuntos
Neoplasias da Mama/genética , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Receptor alfa de Estrogênio/genética , Predisposição Genética para Doença , Polimorfismo Genético/genética , Receptores de Progesterona/genética , Adulto , Idoso , Índice de Massa Corporal , Brasil , Densidade da Mama , Neoplasias da Mama/diagnóstico , Feminino , Frequência do Gene , Genótipo , Humanos , Glândulas Mamárias Humanas/anormalidades , Pessoa de Meia-Idade , Prevalência , Fatores de RiscoRESUMO
Several studies have identified the single nucleotide polymorphism STK15 F31I as a low-penetrance risk allele for breast cancer, but its prevalence and risk association in the Brazilian population have not been determined. The goal of this study was to identify the frequency of this polymorphism in the Brazilian setting. Considering the high degree of admixture of our population, it is of fundamental importance to validate the results already reported in the literature and also to verify the relationship between this variant and breast cancer risk. A total of 750 women without breast cancer were genotyped using the TaqMan PCR assay for STK15 F31I polymorphism. Clinical information was obtained from review of the medical records and mammographic density from the images obtained using the BI-RADS System. The estimated risk of developing cancer was calculated according to the Gail model. The genotypic frequencies observed in this study were 4.5, 38.7, and 56.6 percent, respectively, for the STK15 F31I AA, AT and TT genotypes. The AT and AA genotypes were encountered significantly more often in premenopausal women with moderately dense, dense and heterogeneously dense breast tissue (P = 0.023). In addition, the presence of the TT genotype was significantly associated with age at menarche ≥12 years (P = 0.023). High mammographic density, associated with increased breast cancer risk, was encountered more frequently in premenopausal women with the risk genotypes STK15 F31I AA and AT. The genotypic frequencies observed in our Brazilian sample were similar to those described in other predominantly European populations.
Assuntos
Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/genética , Mamografia , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Neoplasias da Mama/enzimologia , Neoplasias da Mama , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Reação em Cadeia da Polimerase , Prevalência , Fatores de RiscoRESUMO
Several studies have identified the single nucleotide polymorphism STK15 F31I as a low-penetrance risk allele for breast cancer, but its prevalence and risk association in the Brazilian population have not been determined. The goal of this study was to identify the frequency of this polymorphism in the Brazilian setting. Considering the high degree of admixture of our population, it is of fundamental importance to validate the results already reported in the literature and also to verify the relationship between this variant and breast cancer risk. A total of 750 women without breast cancer were genotyped using the TaqMan PCR assay for STK15 F31I polymorphism. Clinical information was obtained from review of the medical records and mammographic density from the images obtained using the BI-RADS System. The estimated risk of developing cancer was calculated according to the Gail model. The genotypic frequencies observed in this study were 4.5, 38.7, and 56.6%, respectively, for the STK15 F31I AA, AT and TT genotypes. The AT and AA genotypes were encountered significantly more often in premenopausal women with moderately dense, dense and heterogeneously dense breast tissue (P = 0.023). In addition, the presence of the TT genotype was significantly associated with age at menarche ≥12 years (P = 0.023). High mammographic density, associated with increased breast cancer risk, was encountered more frequently in premenopausal women with the risk genotypes STK15 F31I AA and AT. The genotypic frequencies observed in our Brazilian sample were similar to those described in other predominantly European populations.
Assuntos
Neoplasias da Mama/genética , Mamografia , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Adulto , Idoso , Aurora Quinase A , Aurora Quinases , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/enzimologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Fatores de RiscoRESUMO
BACKGROUND: Li-Fraumeni and Li-Fraumeni-like syndromes (LFS/LFL), characterised by the development of multiple early onset cancers with heterogeneous tumour patterns, are associated with germline TP53 mutations. Polymorphisms in the TP53 pathway (TP53 PEX4 at codon 72, rs1042522; MDM2 SNP309, rs2279744) have modifier effects on germline TP53 mutations that may account for the individual and familial diversity of tumour patterns. METHODS AND RESULTS: Four polymorphisms were analysed in a series of 135 Brazilian LFS/LFL cancer patients (32 TP53 mutation carriers and 103 wild-type subjects). We report for the first time that another polymorphism in the TP53 gene, TP53 PIN3 (rs17878362), has a strong modifier effect on germline TP53 mutations. This polymorphism, which consists of a 16 bp duplication in intron 3 (A1, non-duplicated allele; A2, duplicated allele), is associated with a difference of 19.0 years in the mean age at the first diagnosis in TP53 mutation carriers (n = 25, A1A1: 28.0 years; n = 7, A1A2: 47.0 years; p = 0.01). In addition, cancer occurrence before the age of 35 years is exclusively observed in A1A1 homozygotes. In this series, the effect of TP53 PEX4 and MDM2 SNP309 on age at diagnosis was similar to the one reported in other series and was smaller than the one of TP53 PIN3 (TP53 PIN3: difference of 19.0 years; TP53 PEX4: 8.3 years; MDM2 SNP309: 12.5 years). CONCLUSION: These results suggest that TP53 PIN3 is another polymorphism in the TP53 pathway that may have a modifier effect on germline TP53 mutations and may contribute to the phenotypic diversity of germline TP53 mutations associated with LFS/LFL patients.
Assuntos
Síndrome de Li-Fraumeni/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteína Supressora de Tumor p53/genética , Adulto , Idade de Início , Brasil/epidemiologia , Distribuição de Qui-Quadrado , Análise Mutacional de DNA , Predisposição Genética para Doença , Haplótipos , Humanos , Síndrome de Li-Fraumeni/diagnóstico , Síndrome de Li-Fraumeni/epidemiologia , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estatísticas não ParamétricasRESUMO
The 5382insC mutation in BRCA1 is a frequently reported mutation, being very prevalent in Central and Eastern Europe. This mutation was recurrently reported in Brazil and one case was reported Portugal, but not in Spain and other South-American countries,. We analyzed the haplotypic profile of seven Brazilian carriers of 5382insC to characterize a possible founder effect. The analyses indicated that mutation carriers shared an identical haplotype. The absence of this mutation in Spain, other South American countries, and sub-Saharan populations, as well as the patients' own ancestry, point to a significant Central or Eastern European contribution to the present genetic background of Brazilian population, different from the population structuring of remaining South American countries.
Assuntos
Neoplasias da Mama/genética , Efeito Fundador , Genes BRCA1 , Mutação , Neoplasias Ovarianas/genética , Adulto , Sequência de Bases , Brasil , Primers do DNA , Feminino , Haplótipos , Humanos , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Misoprostol, a synthetic prostaglandin E1 analog is labeled for the treatment of gastric and duodenal ulcers. In Brazil, where abortion is not a legal procedure, there is a widespread popular misuse of this drug in abortion attempts. This misuse and the fact that, in many cases the desired pregnancy termination does not occur, raise concerns about fetal safety. Case reports of congenital anomalies after maternal use of misoprostol have been published. The objective of this work was to compare pregnancy outcome following misoprostol exposure with a matched control group. This is the first prospective controlled study on fetal safety after misoprostol use. METHODS: A prospective, observational cohort study with 86 exposed and 86 pair-matched, non-exposed controls. RESULTS: There was no significant difference in the rates of major or minor birth between exposed compared to non-exposed infants (2/67 vs 2/81, major defects; 7/67 vs. 3/81, minor anomalies) There were significantly more miscarriages in the exposed group (17.1% vs. 5.8%; relative risk, 2.97; 95% confidence interval, 1.12 to 7.88). There was no statistical difference in gestational age at delivery, birth weight, sex ratio, rate of prematurity, low birth weight, or rates of cesarean section between groups. CONCLUSIONS: Our study, despite its limited statistical power, does not suggest a potent teratogenic action of misoprostol exposure during pregnancy.