Association of the CFH Y402H Polymorphism with the 1-Year Response of Exudative AMD to Intravitreal Anti-VEGF Treatment in the Brazilian Population.

AIM: Evidence of the relationship between the polymorphism of the complement factor H (CFH) gene at position 402 (Y402H) and the response to the treatment of wet AMD is controversial. The aim of this study was to compare the functional and morphological 1-year evolution of patients with exudative AMD treated with antivascular endothelial growth factor (VEGF) drugs with the CFH Y402H polymorphism in the Brazilian population. METHODS: Forty-six patients treated for wet AMD with bevacizumab or ranibizumab in a pro re nata regimen were included. The evolution of best-corrected visual acuity (BCVA) and central retinal thickness (CRT), and the number of injections over 1 year of follow-up were correlated with CFH genotypes. RESULTS: The analysis of variance for the difference between the BCVA denoted as logMAR (logarithm of the minimum angle of resolution) values showed an improvement at 1 year when compared to baseline (p = 0.039). Profile contrast analysis showed that this difference was significant only in the group without the C allele (p = 0.049), without significance in patients presenting with the risk allele (p = 0.241). CRT showed a mean reduction at 1 year compared to baseline (p < 0.001). Significant differences in the profile contrast test were found in the group without the C allele (p < 0.001) and in patients with the risk allele (p = 0.002). No difference was found in the number of injections among the different groups (p = 0.787). CONCLUSIONS: The presence of the risk allele of the Y402H polymorphism in the CFH gene was related to a less favorable evolution over 1 year in this sample of the Brazilian population with exudative AMD who were being treated with anti-VEGF drugs. In agreement with similar previous studies, this study concludes that the CFH risk genotypes may affect the disease response to treatment.

Pharmacogenetic Effect of Complement Factor H Gene Polymorphism in Response to the Initial Intravitreal Injection of Bevacizumab for Wet Age-Related Macular Degeneration.

PURPOSE: To compare the functional and morphological response to the initial intravitreal (IVT) injection of bevacizumab in exudative age-related macular degeneration (AMD) patients with the complement factor H (CFH) gene polymorphism T1277C in the Brazilian population. METHODS: Twenty-five unrelated patients with treatment-naive exudative AMD underwent an IVT injection of 1.25 mg bevacizumab at the initial presentation (D0) and were reexamined 7 days (D7) and 28 days (D28) later. The time and extent of visual acuity (VA) and central retinal thickness (CRT) changes were evaluated according to the presence of the T1277C polymorphism. RESULTS: In the homozygous risk group (CC), VA improvement was detected mostly from D7 to D28, while in the heterozygous (CT) and homozygous for the wild-type allele (TT) groups, functional response occurred earlier, from D0 to D7. Morphological response to the first IVT injection of bevacizumab was significant in the CT and TT groups, while the CC group presented no significant change in CRT up to D28. CONCLUSION: The CC variant of the CFH gene polymorphism T1277C is related to delayed functional and limited morphological response to the initial IVT injection of bevacizumab in exudative AMD patients in a sample of the Brazilian population.

Polymorphism in the HMOX1 gene is associated with high levels of fetal hemoglobin in Brazilian patients with sickle cell anemia.

The aim of this study was to investigate the association between three polymorphisms involved in the oxidative stress pathway and fetal hemoglobin (Hb F) levels in patients with sickle cell anemia in a Brazilian population. One hundred and seven patients with sickle cell anemia were recruited for genomic DNA extraction. The levels of Hb F, sex and age were evaluated. Three polymorphisms, rs4673:T>C and rs9932581:G>A in the CYBA gene and rs2071746:A>T in the HMOX1 gene, were identified through direct sequencing. Hb F levels were not associated with sex, age, or the polymorphisms rs4673:T>C and rs9932581:G>A. However, the TT genotype of the rs2071746:A>T polymorphism was associated with increased levels of Hb F (p value = 0.0131). We observed an association between the TT genotype of the rs2071746:A>T polymorphism, present in the HMOX1 gene, and increased levels of Hb F, indicating the presence of a new marker related to Hb F levels in sickle cell anemia patients.

Correlation between genetic and environmental risk factors for age-related macular degeneration in Brazilian patients.

PURPOSE: To analyze the correlations between age-related macular degeneration (AMD) and genetic and environmental risk factors for in a Brazilian population. DESIGN: Cross-sectional study with a control group. METHODS: We collected data on 236 participants 50 years of age or older (141 with AMD and 95 controls without the disease). Data was obtained using a questionnaire and included information on demographics, ocular and medical history, family history of AMD, lifestyle, and smoking and drinking habits. Genetic evaluations included direct sequencing for the LOC387715 (rs10490924) variant, as well as PCR and enzymatic digestion for the CFH Y402H (rs1061170) and HTRA1 (rs11200638) variants. We performed a risk assessment of environmental risk factors and genetic variants associated with AMD and determined correlations between AMD and the data collected using multiple linear regression analysis. RESULTS: Of the 141 AMD cases, 99 (70%) had advanced AMD in at least one eye (57% neovascular AMD and 13% geographic atrophy), and 42 (30%) had not-advanced AMD. Family history of AMD (OR: 6.58; 95% CI: 1.94-22.31), presence of cardiovascular disease (CVD) (OR: 2.39; 95% CI: 1.08-5.28), low physical activity level (OR: 1.39; 95% CI: 0.82-2.37), and high serum cholesterol (OR: 1.49; 95% CI: 0.84-2.65) were associated with an increased risk for AMD. There was a significant association between CVD and incidence of advanced AMD (OR: 2.29; 95% CI 0.81-6.44). The OR for the risk allele of the LOC387715 gene, the CFH gene and the HTRA1 gene were 2.21 (95% CI: 1.47-3.35), 2.27 (95% CI: 1.52-3.37), and 2.76 (95% CI: 1.89-4.03), respectively. In the stepwise multiple linear regression analyses, the HTRA1 and CFH risk alleles, family history of AMD, the LOC387715 risk allele, and CVD were associated with an increased risk of AMD for a total of 25.6% contribution to the AMD phenotype. CONCLUSIONS: The analysis correlating environmental and genetic risk factors such as family history of AMD, and CVD and the variants of HTRA1, CFH, and LOC387715 genes showed an expressive contribution for the development of AMD among this admixed population.

Evaluation of APOE polymorphisms and the risk for age-related macular degeneration in a Southeastern Brazilian population.

This study aimed to evaluate the role of APOE polymorphisms (rs429358 and rs7412) in the risk of age-related macular degeneration in a sample of the Southeastern Brazilian population. Seven hundred and five unrelated individuals were analyzed, 334 with age-related macular degeneration (case group), and 371 without the disease (control group). In the case group, patients were further stratified according to disease phenotypes, divided into dry and wet age-related macular degeneration, and non-advanced and advanced age-related macular degeneration. APOE polymorphisms (rs429358 and rs7412) were evaluated through polymerase chain reaction and direct sequencing. In the comparison of cases vs. controls, none of the associations reached statistical significance, considering the Bonferroni-adjusted P-value, although there was a suggestive protection for the E3/E4 genotype (OR = 0.626; P-value = 0.037) and E4 carriers (OR = 0.6515; P-value = 0.047). Statistically significant protection for both the E3/E4 genotype and E4 carriers was observed in the comparisons: advanced age-related macular degeneration vs. controls (OR = 0.3665, P-value = 0.491 × 10-3 and OR = 0.4031, P-value = 0.814 × 10-3, respectively), advanced age-related macular degeneration vs. non-advanced age-related macular degeneration (OR = 0.2529, P-value = 0.659 × 10-4 and OR = 0.2692, P-value = 0.631 × 10-4, respectively). In the comparison of wet age-related macular degeneration vs. control, protection was statistically significant only for E3/E4 (OR = 0.4052, P-value = 0.001). None of the comparisons demonstrated any significant association for E2 genotypes or E2 carriers in age-related macular degeneration risk in this study. Findings suggest a protective role of the E4 haplotype in the APOE gene in the risk for advanced and wet forms of age-related macular degeneration, in a sample of the Brazilian population. To our knowledge, this is the first Brazilian study to show the association between APOE polymorphisms and age-related macular degeneration.

Association of genetic variants rs641153 (CFB), rs2230199 (C3), and rs1410996 (CFH) with age-related macular degeneration in a Brazilian population.

This study aimed to investigate the association among genetic variants of the complement pathway CFB R32Q (rs641153), C3 R102G (rs2230199), and CFH (rs1410996) with age-related macular degeneration (AMD) in a sample of the Brazilian population. In a case-control study, 484 AMD patients were classified according to the clinical age-related maculopathy grading system (CARMS) and compared to 479 unrelated controls. The genetic variants rs1410996 of complement H (CFH), rs641153 of complement factor B (CFB), and rs2230199 of complement 3 (C3) were evaluated through polymerase chain reaction (PCR) and direct sequencing. The associations between single nucleotide polymorphisms (SNPs) and AMD, adjusted by age, were assessed by using logistic regression models. A statistically significant association was observed between AMD risk and rs2230199 variant with an OR of 2.01 (P = 0.0002) for CG individuals compared to CC individuals. Regarding the comparison of advanced AMD versus the control group, the OR was 2.12 (P = 0.0036) for GG versus AA genotypes for rs1410996 variant. Similarly, the OR for rs2230199 polymorphism was 2.3034 (P = 5.47e-05) when comparing CG individuals to CC carriers. In contrast, the rs641153 variant showed a significant protective effect against advanced AMD for GA versus GG genotype (OR = 0.4406; P = 0.0019). When comparing wet AMD versus controls, a significant association was detected for rs1410996 variant (OR = 2.16; P = 0.0039) comparing carriers of the homozygous GG versus AA genotype, as well as in the comparisons of GG (OR = 3.0713; P = 0.0046) and CG genotypes (OR = 2.2249; P = 0.0002) versus CC genotype for rs2230199 variant, respectively. The rs641153 variant granted a significant protective effect against wet AMD for GA versus GG genotypes (OR = 0.4601; P = 0.0044). Our study confirmed the risk association between rs2230199 and rs1410996 variants and AMD, and the protective role against AMD for rs641153 variant.

Identification of SARS-CoV-2 on the ocular surface in a cohort of COVID-19 patients from Brazil.

In this cross-sectional study, we investigate the presence of Severe Acute Respiratory Syndrome Coronavirus 2 Ribonucleic Acid (SARS-CoV-2 RNA) in the tears of hospitalized COVID-19 patients. After laboratory confirmation of SARS-CoV-2 infection by reverse transcription polymerase chain reaction (RT-PCR) analysis, tear samples from both eyes of each patient were collected using conjunctival swab for RT-PCR. Detailed demographic profile, systemic and ocular symptoms, comorbidities, clinical, ancillary, and ocular manifestations were evaluated. Of the 83 patients enrolled in the study, 7 (8.43%) had SARS-CoV-2 RNA detected in the tear samples. Neutrophils' count, C-reactive protein, and D-dimer were higher in patients with SARS-CoV-2 detected in tears than in patients without virus in ocular surface samples. One patient with SARS-CoV-2 in tears showed mild ocular eyelid edema, hyperemia, and chemosis. No relevant ocular manifestations were detected in the other patients. Although the levels of viral RNA on ocular surface samples were low for most patients (5/7), with positivity only for gene N and CT higher than 30, two patients were positive for all viral targets tested (N, E, and RpRd), with viral load near 1 × 105 ePFU/mL, indicating that the ocular transmission of SARS-CoV-2 is a possibility that needs to be considered, especially in the hospital environment. Further studies need to be conducted to demonstrate whether infective viral particles could be isolated from tears.

Angiogenesis-Related Genes in Endothelial Progenitor Cells May Be Involved in Sickle Cell Stroke.

Background The clinical aspects of sickle cell anemia (SCA) are heterogeneous, and different patients may present significantly different clinical evolutions. Almost all organs can be affected, particularly the central nervous system. Transient ischemic events, infarcts, and cerebral hemorrhage can be observed and affect ≈25% of the patients with SCA. Differences in the expression of molecules produced by endothelial cells may be associated with the clinical heterogeneity of patients affected by vascular diseases. In this study, we investigated the differential expression of genes involved in endothelial cell biology in SCA patients with and without stroke. Methods and Results Endothelial progenitor cells from 4 SCA patients with stroke and 6 SCA patients without stroke were evaluated through the polymerase chain reaction array technique. The analysis of gene expression profiling identified 29 differentially expressed genes. Eleven of these genes were upregulated, and most were associated with angiogenesis (55%), inflammatory response (18%), and coagulation (18%) pathways. Downregulated expression was observed in 18 genes, with the majority associated with angiogenesis (28%), apoptosis (28%), and cell adhesion (22%) pathways. Remarkable overexpression of the MMP1 (matrix metalloproteinase 1) gene in the endothelial progenitor cells of all SCA patients with stroke (fold change: 204.64; P=0.0004) was observed. Conclusions Our results strongly suggest that angiogenesis is an important process in sickle cell stroke, and differences in the gene expression profile of endothelial cell biology, especially MMP1, may be related to stroke in SCA patients.

Evaluation of oxidative stress-related genetic variants for predicting stroke in patients with sickle cell anemia.

Overt stroke in adults with sickle cell anemia (SCA) continues to be a major cause of morbidity and mortality, while no evidence-based strategy for prevention has been reached so far. Although transcranial Doppler ultrasonography represents the most important tool for identifying young patients with SCA at risk of primary stroke, strategies for stroke prediction in adulthood remain challenging. Emerging data suggest that oxidative stress may exert a pivotal role in the pathogenesis of ischemic brain injury. Combining these pieces of evidences with the well-known genetic contribution to the development of stroke in SCA, we hypothesized that genetic variants related to the biology of oxidative stress could be used to identify adult patients at higher risk of stroke. Overall, 499 unrelated patients with SCA aged >18 years were genotyped for SOD2 Val16Ala (rs4880), GPX3 T-568C (rs8177404), GPX3 T-518C (rs8177406), GPX3 T-65C (rs8177412), and CAT01 C-262 T (rs1001179) polymorphisms, along with α-thalassemia status and ß-globin gene haplotypes. Of these, only the SOD2 Val16Ala polymorphism was associated with stroke. SOD2 Val16Ala polymorphism was independently associated with risk of stroke (odds ratio: 1.98; 95% confidence interval [CI]: 1.18-3.32; P = .009) and with the long-term cumulative incidence of stroke (hazard ratio: 2.24, 95% CI: 1.3-3.9; P = .004). In summary, we provide evidence that oxidative stress-related genetic variants, in particular, the SOD2 Val16Ala polymorphism, may represent a simple and inexpensive alternative for identifying patients at risk of stroke.

Different morphological and gene expression profile in placentas of the same sickle cell anemia patient in pregnancies of opposite outcomes.

IMPACT STATEMENT: Environmentally induced changes in placental morphological and molecular phenotypes may provide relevant insight towards pathophysiology of diseases. The rare opportunity to evaluate the same patient, with sickle cell anemia (SCA), in two different pregnancies, of opposite outcomes (one early onset severe preeclampsia (PE) and the other mostly non-complicated) can prove such concept. In addition, the comparison to other conditions of known placental and vascular/inflammatory involvement strengthens such findings. Our results suggest that the clinical association between SCA and PE can be supported by common pathophysiological mechanisms, but that pathways involving response to copper and triglyceride metabolism may be important drivers of the pathophysiology of PE. Future studies using in a larger number of samples should confirm these findings and explore pathways involved in the pathophysiology of PE and its relationship with SCA.

Association between IL1A and IL1B polymorphisms and primary open angle glaucoma in a Brazilian population.

Abstract: The aim of this study was to investigate the association of five polymorphisms in the IL1A and IL1B genes in Brazilian patients with primary open angle glaucoma (POAG). A case­control study, including 214 unrelated POAG patients and 187 healthy individuals, was conducted to evaluate the frequency of polymorphisms in the IL1A and IL1B genes. Ophthalmic evaluation was performed and genomic DNA was obtained from all participants. Five single nucleotide polymorphisms (SNPs): IL1A (­889C/T: rs1800587:C > T, +4845G/T:rs17561G>T) and IL1B (­31C/T:rs1143627:T > C, ­511C/T:rs16944C>T and +3954C/T:rs1143634:C > T) were genotyped through direct sequencing. The association of individual SNPs was tested using logistic regression. There was an association between the ­31C/T and ­511 C/T polymorphisms in the IL1B gene with POAG (p = 0.002 and p = 0.009, respectively). High linkage disequilibrium was observed between the ­31C/T and ­511C/T polymorphisms. The statistical analysis showed that the T/C haplotype (­31/­511) in the IL1B gene is more frequent in controls (p = 0.011) and the C/T haplotype (­31/­511) is more common in POAG patients (p = 0.018). Among POAG cases, the genotypic distribution of the ­31C/T and ­511 C/T SNPs was significantly different in patients who underwent anti-glaucomatous surgery compared to patients without surgery (p = 0.016 and 0.023, respectively). There was no statistically significant difference for the remaining SNPs between POAG patients and controls. In conclusion, the C allele of the ­31C/T and the T allele of the ­511C/T polymorphisms in the IL1B gene may represent a "risk haplotype" for the development of POAG in Brazilian individuals. Further studies with larger cohorts of patients are necessary to substantiate these findings.

Haptoglobin polymorphism and diabetic retinopathy in Brazilian patients.

Haptoglobin (Hp) is an acute phase protein with antioxidant and immunomodulatory properties. Three main genotypes/phenotypes (Hp1-1, Hp2-1 and Hp2-2) show distinct efficiencies in these activities and have been associated with susceptibility and outcome in several diseases, including diabetes mellitus (DM). It has been suggested that Hp polymorphism may influence the development of retinopathy, an important microvascular complication in DM. In order to investigate this association in a Brazilian population, we determined the Hp genotypes of 317 diabetic patients with at least 10 years of disease. The patients were classified as DM-type 1 and 2, with and without diabetic retinopathy (DR). The Hp genotype frequencies of the different patient groups and of a control group consisting of 142 healthy individuals who had previously been studied were compared. No significant differences were observed for the three Hp genotypes. Hemoglobin A1c levels, systolic blood pressure (SBP), diastolic blood pressure (DBP) and duration of diabetes, which are potential risk factors for DR, were also compared. Again no significant differences were observed for the three Hp genotypes. Thus, we conclude that this polymorphism is not associated with the presence of DR in the Brazilian population studied here.

[Mutation screening in Angiotensin II receptors, AGTR1 and AGTR2, and evaluation of AGTR1 polymorphisms C573T and A1166C in patients with premature adrenarche]. / Triagem de mutações nos receptores de Angiotensina II, AGTR1 e AGTR2 e avaliação dos polimorfismos C573T e A1166C do gene AGTR1 em pacientes com adrenarca precoce idiopática.

Precocious pubarche is the appearance of pubic hair before the age of 8 years in girls and 9 years in boys. The most frequent etiology is idiopathic precocious adrenarche, suggested, after long-term follow-up, to be associated with metabolic syndrome. One of the factors involved in the genesis of precocious adrenarche is Angiotensin II (Ang II), which promotes cell proliferation and steroidogenesis through type 1 (AT1) and type 2 (AT2) receptors. In order to study Ang II receptors mutations, 50 children with idiopathic precocious adrenarche were evaluated and compared to a control group of normal individuals. Mutations were not detected in the AGTR1 and AGTR2 genes; however, two polymorphisms were identified in the AGTR1 gene: the C573T (exon 5) and the A1166C (3' untranslated region). The polymorphic allele T573 was found in 35% of the patients and 38% of controls. The polymorphic allele C1166 was present in 24% of the patients and 26% of controls. There was no statistical difference between groups. There was also no correlation between the polymorphisms and clinical and laboratory findings, as well as their family history of metabolic syndrome.

A novel mutation in the GJA1 gene in a family with oculodentodigital dysplasia.

OBJECTIVES: To describe a Brazilian family with oculodentodigital dysplasia (ODDD) and to screen for mutations in the gap junction protein alpha 1 (GJA1) gene in this family. METHODS: Twelve members of a 3-generation family with ODDD underwent screening for mutations of the GJA1 gene and a comprehensive ophthalmic examination. We defined ODDD on the basis of clinical characteristics described in this syndrome (microdontia, caries, enamel hypoplasia, thin nose, and syndactyly) and eye abnormalities such as microphthalmos, iris atrophy, and glaucoma. Direct sequencing of the GJA1 gene was performed using DNA collected from peripheral blood. A control group of 60 healthy individuals underwent evaluation by means of enzyme digestion. RESULTS: Among the 8 members of this family who were characterized as having ODDD, 2 showed chronic angle-closure glaucoma, and 1 had open-angle glaucoma. A new mutation in the GJA1 gene was identified, consisting of a change from proline to histidine at codon 59. This mutation segregated through members with the ODDD phenotype. Analysis of the control group by means of restriction fragment length polymorphism (MvaI enzyme) did not disclose this mutation. CONCLUSION: Our results demonstrate a new mutation (P59H) in the GJ1A gene, identified in a family with ODDD syndrome. Clinical Relevance The presence of different forms of glaucoma in families with ODDD may indicate a new mutation in the GJA1 gene.

Molecular genetics of primary congenital glaucoma in Brazil.

PURPOSE: To determine the distribution of CYP1B1 gene mutations in Brazilian patients with primary congenital glaucoma (PCG). METHODS: PCG diagnosis was established by presence of buphthalmos in at least one affected eye and associated high intraocular pressures before the age of 3 years. CYP1B1 mutation screening of 52 patients with PCG was performed by SSCP and direct sequencing of PCR fragments. RESULTS: Eleven mutations, four of which are novel, were observed in 26 (50%) individuals. A new frameshift mutation (4340delG) was observed in 20.2% of all individuals screened. These individuals had early-onset, bilateral glaucoma that necessitated multiple surgical interventions. CYP1B1 mutations were twice as frequent in affected individuals of European descent as in individuals of African descent. Analysis of six intragenic single nucleotide polymorphisms (SNPs) established 5'-C-C-G-G-T-A-3' as the most common haplotype among the affected Brazilian individuals. A nonsense mutation (W57X) previously reported in an individual with Peters anomaly (compound heterozygote) was also observed in two individuals with PCG but combined with different mutations. A newly developed SSCP assay enabled us to detect all DNA mutations and polymorphisms previously detected by direct sequencing. CONCLUSIONS: Our results indicate that CYP1B1 mutations may be responsible for half of cases of PCG in the Brazilian population. The SNP haplotype 5'-C-C-G-G-T-A-3' was associated with the majority of CYP1B1 mutations. This haplotype harbors the high-activity V432 allele, which is emerging as a putative susceptibility factor in several cancers.

Molecular characterization of hemoglobin alpha-D chains from Geochelone carbonaria and Geochelone denticulata land turtles.

In order to help elucidate the evolution of alpha-globins, the complete cDNA and amino acid sequences of Geochelone carbonaria and Geochelone denticulata land turtles alpha-D chains have been described. In G. carbonaria, the cDNA is 539 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 520. In G. denticulata, the cDNA is 536 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 517. Both cDNAs codify 141 amino acid residues, differing from each other in only four amino acid residues. When comparing with human Hb alpha-chain, alterations in important regions can be noted: alpha110 Ala-Gly, alpha114 Pro-Gly, alpha117 Phe-Tyr and alpha122 His-Gln. There is a high homology between the amino acids of these turtles when compared with chicken alpha-D chains, progressively decreasing when compared with human, crocodile, snake, frog and fish alpha-chains. Phylogenetic analysis of alpha-D chains shows that those of turtles are closer to those of birds than to snakes and lizards.

Myocilin mt.1 gene promoter single nucleotide polymorphism (-1000C>G) in Brazilian patients with primary open angle glaucoma.

BACKGROUND: The myocilin (MYOC) gene promoter polymorphism -1000C>G (MYOC mt.1) can be associated with faster progression of primary open angle glaucoma (POAG). The purpose of this study was to investigate the MYOC mt.1 in Brazilian patients with POAG and to evaluate its possible role on the phenotype and the severity of the disease. MATERIAL AND METHODS: One hundred sixty-seven POAG patients and 130 normal controls were enrolled. DNA samples were prepared and the MYOC mt.1 polymorphism was screened by real-time polymerase chain reaction (RT-PCR) in an Single-nucleotide polymorphism (SNP) assay. Frequencies of the MYOC mt.1 promoter polymorphism were determined for both groups and compared by Fisher's exact test and Chi-square test with Yate's correction. Intraocular pressure (IOP), cup-to-disc ratio (C/D), number of glaucoma medications, and number of glaucoma surgeries were compared between MYOC mt.1 carriers and non-carriers. RESULTS: MYOC mt.1 genotype frequencies did not differ between POAG and controls (P = 0.420); 14.6% of controls and 16.4% of POAG patients were MYOC mt.1 carriers (CG or GG). Frequencies of the G allele were similar between glaucomatous patients and controls (7.3% and 9.2%, respectively; P = 0.477). Among POAG patients, there were no differences in mean C/D ratio, IOP, number of glaucoma medications, and surgical procedures for IOP control between carries and non-carriers of the MYOC mt.1 promoter polymorphism (p>0.05). CONCLUSION: The G allele of the MYOC mt.1 promoter polymorphism was equally distributed among POAG patients and healthy subjects and it is possibly unrelated to the risk and severity of disease in the Brazilian population.

DNAase I hypersensitive site 3' to the beta-globin gene cluster contains a TAA insertion specific for beta(S)-Benin haplotype.

BACKGROUND AND OBJECTIVES: Analysis of DNA polymorphic sites is a powerful tool for detection of gene flow in human evolutionary studies and to trace genetic background associated with abnormal genes. The beta-globin locus contains more than 20 single-base restriction fragment length polymorphism (RFLP) sites spanning over 80 kb on chromosome 11. Far downstream of the expressed genes, there is a hypersensitive site (HS). The function of the 3'-HS remains unknown. As an approach to the understanding of the 3'-HS region in sickle cell anemia we searched for sequence polymorphism in the AT-rich region, using a non-radioactive polymerase chain reaction (PCR)-single strand conformational polymorphism (SSCP) technique. DESIGN AND METHODS: A 460 bp fragment located at the 3' of the b globin gene was amplified from patients (with sickle cell anemia and HbSC disease), and from AS individuals. Standard RFLP-haplotyping was performed and compared with the PCR-SSCP screening strategy. RESULTS: Two distinct band patterns were revealed by SSCP testing, each one in strict linkage disequilibrium with either Benin or Bantu haplotypes. Direct sequencing of the amplified segment revealed a TAA insertion in the AT-rich region, in all 121 beta(S) Benin chromosomes tested, but not in other beta(S) haplotypes from the total of 380 beta(S) chromosomes typed. INTERPRETATION AND CONCLUSIONS: SSCP analysis could easily distinguish sequence variations in the 3'AT-rich region of the beta-globin cluster, and a TAA insertion in this region seems to be specific for the Benin-beta(S) chromosome.

Mutations in the p53 gene in acute myeloid leukemia patients correlate with poor prognosis.

Inactivation of tumor suppressor genes, whose products exert an inhibitory influence on cell cycle progression, can lead to neoplastic transformation. In acute myeloid leukemia (AML), the frequency of p53 gene mutations ranges from 4 to 15% in populations from USA and Europe. In an attempt to investigate the frequency of point mutations in the p53 gene in AML Brazilian patients, DNA samples of 35 patients were studied using PCR-SSCP techniques, screening exons 4-10. Mutations were identified in bone marrow DNA in 5 of the 35 AML patients (14.3%), a frequency similar to those reported for Northern American and European populations. The overall survival of patients with mutations in the p53 gene was significantly shorter than for patients without mutations.

Triagem de mutações nos receptores de Angiotensina II, AGTR1 e AGTR2 e avaliação dos polimorfismos C573T e A1166C do gene AGTR1 em pacientes com adrenarca precoce idiopática / Mutation screening in Angiotensin II receptors, AGTR1 and AGTR2, and evaluation of AGTR1 polymorphisms C573T and A1166C in patients with premature adrenarche / Mutation screening in Angiotensin II receptors, AGTR1 and AGTR2, and evaluation of AGTR1 polymorphisms C573T and A1166C in patients with premature adrenarche

Pubarca precoce é o aparecimento de pêlos pubianos antes dos 8 anos em meninas e 9 anos em meninos, sendo sua etiologia mais freqüente a adrenarca precoce idiopática, a longo prazo, associada à síndrome metabólica. Dentre os fatores envolvidos na gênese da adrenarca precoce podemos citar a Angiotensina II (Ang II), a qual promove proliferação celular e esteroidogênese, podendo agir através de dois receptores, o tipo 1 (AT1) e o tipo 2 (AT2). Com o intuito de estudar mutações dos genes dos receptores da AngII, foram avaliadas 50 crianças com diagnóstico de adrenarca precoce idiopática e comparadas ao grupo controle de indivíduos normais. Não foram detectadas mutações dos genes AGTR1 e AGTR2, contudo dois polimorfismos foram identificados no gene AGTR1: o polimorfismo C573T (localizado no exon 5) e o A1166C (na região 3' não codificadora). A freqüência do alelo polimórfico T573 foi de 35 por cento nos pacientes e 38 por cento nos controles. O alelo polimórfico C1166 esteve presente em 24 por cento dos pacientes e em 26 por cento dos controles. Não houve diferença significante entre os grupos, assim como não houve correlação entre a freqüência dos polimorfismos C573T e A1166C e as variáveis clínicas e laboratoriais dos pacientes, ou com sua história familial de síndrome metabólica.

Precocious pubarche is the appearance of pubic hair before the age of 8 years in girls and 9 years in boys. The most frequent etiology is idiopathic precocious adrenarche, suggested, after long-term follow-up, to be associated with metabolic syndrome. One of the factors involved in the genesis of precocious adrenarche is Angiotensin II (Ang II), which promotes cell proliferation and steroidogenesis through type 1 (AT1) and type 2 (AT2) receptors. In order to study Ang II receptors mutations, 50 children with idiopathic precocious adrenarche were evaluated and compared to a control group of normal individuals. Mutations were not detected in the AGTR1 and AGTR2 genes; however, two polymorphisms were identified in the AGTR1 gene: the C573T (exon 5) and the A1166C (3' untranslated region). The polymorphic allele T573 was found in 35 percent of the patients and 38 percent of controls. The polymorphic allele C1166 was present in 24 percent of the patients and 26 percent of controls. There was no statistical difference between groups. There was also no correlation between the polymorphisms and clinical and laboratory findings, as well as their family history of metabolic syndrome.