GUILHERME LOPES YAMAMOTO
Projetos de Pesquisa
Unidades Organizacionais
Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/36 - Laboratório de Pediatria Clínica, Hospital das Clínicas, Faculdade de Medicina
LIM/36 - Laboratório de Pediatria Clínica, Hospital das Clínicas, Faculdade de Medicina
10 resultados
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- Whole-genome sequencing of 1,171 elderly admixed individuals from Sao Paulo, Brazil(2022) NASLAVSKY, Michel S.; SCLIAR, Marilia O.; YAMAMOTO, Guilherme L.; WANG, Jaqueline Yu Ting; ZVERINOVA, Stepanka; KARP, Tatiana; NUNES, Kelly; CERONI, Jose Ricardo Magliocco; CARVALHO, Diego Lima de; SIMOES, Carlos Eduardo da Silva; BOZOKLIAN, Daniel; NONAKA, Ricardo; SILVA, Nayane dos Santos Brito; SOUZA, Andreia da Silva; ANDRADE, Heloisa de Souza; PASSOS, Marilia Rodrigues Silva; CASTRO, Camila Ferreira Bannwart; MENDES-JUNIOR, Celso T.; V, Rafael L. Mercuri; MILLER, Thiago L. A.; BUZZO, Jose Leonel; REGO, Fernanda O.; ARAUJO, Nathalia M.; MAGALHAES, Wagner C. S.; MINGRONI-NETTO, Regina Celia; BORDA, Victor; GUIO, Heinner; ROJAS, Carlos P.; SANCHEZ, Cesar; CACERES, Omar; DEAN, Michael; BARRETO, Mauricio L.; LIMA-COSTA, Maria Fernanda; HORTA, Bernardo L.; TARAZONA-SANTOS, Eduardo; MEYER, Diogo; GALANTE, Pedro A. F.; GURYEV, Victor; CASTELLI, Erick C.; DUARTE, Yeda A. O.; PASSOS-BUENO, Maria Rita; ZATZ, MayanaAs whole-genome sequencing (WGS) becomes the gold standard tool for studying population genomics and medical applications, data on diverse non-European and admixed individuals are still scarce. Here, we present a high-coverage WGS dataset of 1,171 highly admixed elderly Brazilians from a census-based cohort, providing over 76 million variants, of which similar to 2 million are absent from large public databases. WGS enables identification of similar to 2,000 previously undescribed mobile element insertions without previous description, nearly 5 Mb of genomic segments absent from the human genome reference, and over 140 alleles from HLA genes absent from public resources. We reclassify and curate pathogenicity assertions for nearly four hundred variants in genes associated with dominantly-inherited Mendelian disorders and calculate the incidence for selected recessive disorders, demonstrating the clinical usefulness of the present study. Finally, we observe that whole-genome and HLA imputation could be significantly improved compared to available datasets since rare variation represents the largest proportion of input from WGS. These results demonstrate that even smaller sample sizes of underrepresented populations bring relevant data for genomic studies, especially when exploring analyses allowed only by WGS.
- Rare variants in SOS2 and LZTR1 are associated with Noonan syndrome(2015) YAMAMOTO, Guilherme Lopes; AGUENA, Meire; GOS, Monika; HUNG, Christina; PILCH, Jacek; FAHIMINIYA, Somayyeh; ABRAMOWICZ, Anna; CRISTIAN, Ingrid; BUSCARILLI, Michelle; NASLAVSKY, Michel Satya; MALAQUIAS, Alexsandra C.; ZATZ, Mayana; BODAMER, Olaf; MAJEWSKI, Jacek; JORGE, Alexander A. L.; PEREIRA, Alexandre C.; KIM, Chong Ae; PASSOS-BUENO, Maria Rita; BERTOLA, Debora RomeoBackground Noonan syndrome is an autosomal dominant, multisystemic disorder caused by dysregulation of the RAS/mitogen activated protein kinase (MAPK) pathway. Heterozygous, pathogenic variants in 11 known genes account for approximately 80% of cases. The identification of novel genes associated with Noonan syndrome has become increasingly challenging, since they might be responsible for very small fractions of the cases. Methods A cohort of 50 Brazilian probands negative for pathogenic variants in the known genes associated with Noonan syndrome was tested through whole-exome sequencing along with the relatives in the familial cases. Families from the USA and Poland with mutations in the newly identified genes were included subsequently. Results We identified rare, segregating or de novo missense variants in SOS2 and LZTR1 in 4% and 8%, respectively, of the 50 Brazilian probands. SOS2 and LZTR1 variants were also found to segregate in one American and one Polish family. Notably, SOS2 variants were identified in patients with marked ectodermal involvement, similar to patients with SOS1 mutations. Conclusions We identified two novel genes, SOS2 and LZTR1, associated with Noonan syndrome, thereby expanding the molecular spectrum of RASopathies. Mutations in these genes are responsible for approximately 3% of all patients with Noonan syndrome. While SOS2 is a natural candidate, because of its homology with SOS1, the functional role of LZTR1 in the RAS/MAPK pathway is not known, and it could not have been identified without the large pedigrees. Additional functional studies are needed to elucidate the role of LZTR1 in RAS/MAPK signalling and in the pathogenesis of Noonan syndrome.
- Natural history of 39 patients with Achondroplasia(2018) CERONI, Jose Ricardo Magliocco; SOARES, Diogo Cordeiro de Queiroz; TESTAI, Larissa de Cassia; KAWAHIRA, Rachel Sayuri Honjo; YAMAMOTO, Guilherme Lopes; SUGAYAMA, Sofia Mizuho Miura; OLIVEIRA, Luiz Antonio Nunes de; BERTOLA, Debora Romeo; KIM, Chong AeOBJECTIVES: To characterize the natural history of 39 achondroplastic patients diagnosed by clinical, radiological and molecular assessments. METHODS: Observational and retrospective study of 39 patients who were attended at a public tertiary level hospital between 1995 and 2016. RESULTS: Diagnosis was made prenatally in 11 patients, at birth in 9 patients and within the first year of life in 13 patients. The most prevalent clinical findings were short stature, high forehead, trident hands, genu varum and macrocephaly. The most prevalent radiographic findings were rhizomelic shortening of the long bones and narrowing of the interpediculate distance of the caudal spine. There was motor developmental delay in 18 patients and speech delay in 16 patients. The most common clinical intercurrences were middle ear dysfunction, sleep apnea, limb pain and obesity from 2 to 9 years of age. One patient was large for the gestational age but did not develop obesity. One patient developed hydrocephalus at 10 years old. The current age of the patients varies from 15 months to 36 years. The molecular study performed by Sanger sequencing of the common heterozygous mutation 1138G >A in FGFR3 was positive in all patients. Four cases were inherited, and 35 were sporadic (paternal age from 19 to 66 years). CONCLUSIONS: The diagnoses were made early based on clinical and radiographic findings. All cases were confirmed molecularly. Despite presenting a benign course, it is necessary to establish a systematic protocol for the surveillance of these patients due to the common clinical intercurrences.
- Nutritional Aspects of Noonan Syndrome and Noonan-Related Disorders(2016) SILVA, Fernanda Marchetto da; JORGE, Alexander Augusto; MALAQUIAS, Alexandra; PEREIRA, Alexandre da Costa; YAMAMOTO, Guilherme Lopes; KIM, Chong Ae; BERTOLA, DeboraRasopathies are a group of rare disorders characterized by neurocardiofaciocutaneous involvement, and caused by mutations in several genes of the RAS/MAPK pathway. In the present study, we characterized growth parameters, body composition, and nutritional aspects of children and adults (n = 62) affected by these disorders, mainly Noonan syndrome, using an indirect method-anthropometry-and a 24-hr recall questionnaire. The growth parameters in our cohort showed short stature, especially in individuals with RAF1 and SHOC2 mutations, lower obesity rates compared to the control population, and BMI scores highest in individuals with BRAF mutations and lowest in individuals with SHOC2. Body composition showed a compromise in the upper arm muscle circumference, with a statistically significant difference in the z-score of triceps skin-fold (P = 0.0204) and upper arm fat area (P = 0.0388) between BRAF and SHOC2 groups and in the z-score of triceps skinfold between RAF1 and SHOC2 (P = 0.0218). The pattern of macro-nutrient consumption was similar to the control population. Our study is the first to address body composition in RASopathy individuals and the data indicate a compromise not only in adipose tissue, but also in muscle mass. Studies using different techniques, such as dual-energy X-ray absorptiometry or imaging studies, which give a more precise delineation of fat and non-fat mass, are required to confirm our results, ultimately causing an impact on management strategies. (C) 2016 Wiley Periodicals, Inc.
- Manifesting carriers of X-linked myotubular myopathy Genetic modifiers modulating the phenotype(2020) SOUZA, Lucas Santos; ALMEIDA, Camila Freitas; YAMAMOTO, Guilherme Lopes; PAVANELLO, Rita de Cassia Mingroni; GURGEL-GIANNETTI, Juliana; COSTA, Silvia Souza da; ANEQUINI, Isabela Pessa; CARMO, Silvana Amanda do; WANG, Jaqueline Yu Ting; SCLIAR, Marilia de Oliveira; CASTELLI, Erick C.; OTTO, Paulo Alberto; ZANOTELI, Edmar; VAINZOF, MarizObjective To analyze the modulation of the phenotype in manifesting carriers of recessive X-linked myotubular myopathy (XLMTM), searching for possible genetic modifiers. Methods Twelve Brazilian families with XLMTM were molecularly and clinically evaluated. In 2 families, 4 of 6 and 2 of 5 manifesting female carriers were identified. These females were studied for X chromosome inactivation. In addition, whole-exome sequencing was performed, looking for possible modifier variants. We also determined the penetrance rate among carriers of the mutations responsible for the condition. Results Mutations in the MTM1 gene were identified in all index patients from the 12 families, being 4 of them novel. In the heterozygotes, X chromosome inactivation was random in 3 of 4 informative manifesting carriers. The disease penetrance rate was estimated to be 30%, compatible with incomplete penetrance. Exome comparative analyses identified variants within a segment of 4.2 Mb on chromosome 19, containing the killer cell immunoglobulin-like receptor cluster of genes that were present in all nonmanifesting carriers and absent in all manifesting carriers. We hypothesized that these killer cell immunoglobulin-like receptor variants may modulate the phenotype, acting as a protective factor in the nonmanifesting carriers. Conclusions Affected XLMTM female carriers have been described with a surprisingly high frequency for a recessive X-linked disease, raising the question about the pattern of inheritance or the role of modifier factors acting on the disease phenotype. We demonstrated the possible existence of genetic mechanisms and variants accountable for the clinical manifestation in these women, which can become future targets for therapies.
- Targeted Molecular Investigation in Patients within the Clinical Spectrum of Auriculocondylar Syndrome(2017) TAVARES, Vanessa L. Romanelli; ZECHI-CEIDE, Roseli M.; BERTOLA, Debora R.; GORDON, Christopher T.; FERREIRA, Simone G.; HSIA, Gabriella S. P.; YAMAMOTO, Guilherme L.; EZQUINA, Suzana A. M.; KOKITSU-NAKATA, Nancy M.; VENDRAMINI-PITTOLI, Siulan; FREITAS, Renato S.; SOUZA, Josiane; RAPOSO-AMARAL, Cesar A.; ZATZ, Mayana; AMIEL, Jeanne; GUION-ALMEIDA, Maria L.; PASSOS-BUENO, Maria RitaAuriculocondylar syndrome, mainly characterized by micrognathia, small mandibular condyle, and question mark ears, is a rare disease segregating in an autosomal dominant pattern in the majority of the families reported in the literature. So far, pathogenic variants in PLCB4, GNAI3, and EDN1 have been associated with this syndrome. It is caused by a developmental abnormality of the first and second pharyngeal arches and it is associated with great inter- and intra-familial clinical variability, with some patients not presenting the typical phenotype of the syndrome. Moreover, only a few patients of each molecular subtype of Auriculocondylar syndrome have been reported and sequenced. Therefore, the spectrum of clinical and genetic variability is still not defined. In order to address these questions, we searched for alterations in PLCB4, GNAI3, and EDN1 in patients with typical Auriculocondylar syndrome (n - 3), Pierre Robin sequence-plus (n - 3), micrognathia with additional craniofacial malformations (n - 4), or non-specific auricular dysplasia (n - 1), which could represent subtypes of Auriculocondylar syndrome. We found novel pathogenic variants in PLCB4 only in two of three index patients with typical Auriculocondylar syndrome. We also performed a detailed comparative analysis of the patients presented in this study with those previously published, which showed that the pattern of auricular abnormality and full cheeks were associated with molecularly characterized individuals with Auriculocondylar syndrome. Finally, our data contribute to a better definition of a set of parameters for clinical classification that may be used as a guidance for geneticists ordering molecular testing for Auriculocondylar syndrome. (C) 2017 Wiley Periodicals, Inc.
- Biallelic variants in DNA2 cause poikiloderma with congenital cataracts and severe growth failure reminiscent of Rothmund-Thomson syndrome(2023) LAZZARO FILHO, Ricardo Di; YAMAMOTO, Guilherme Lopes; SILVA, Tiago J.; ROCHA, Leticia A.; LINNENKAMP, Bianca D. W.; CASTRO, Matheus Augusto Araujo; BARTHOLDI, Deborah; SCHALLER, Andre; LEEB, Tosso; KELMANN, Samantha; UTAGAWA, Claudia Y.; STEINER, Carlos E.; STEINMETZ, Leandra; HONJO, Rachel Sayuri; KIM, Chong Ae; WANG, Lisa; ABOURJAILI-BILODEAU, Raphael; CAMPEAU, Philippe; WARMAN, Matthew; PASSOS-BUENO, Maria Rita; HOCH, Nicolas C.; BERTOLA, Debora RomeoRothmund-Thomson syndrome (RTS) is a rare, heterogeneous autosomal recessive genodermatosis, with poikiloderma as its hallmark. It is classified into two types: type I, with biallelic variants in ANAPC1 and juvenile cataracts, and type II, with biallelic variants in RECQL4, increased cancer risk and no cataracts. We report on six Brazilian probands and two siblings of Swiss/Portuguese ancestry presenting with severe short stature, widespread poikiloderma and congenital ocular anomalies. Genomic and functional analysis revealed compound heterozygosis for a deep intronic splicing variant in trans with loss of function variants in DNA2, with reduction of the protein levels and impaired DNA double-strand break repair. The intronic variant is shared by all patients, as well as the Portuguese father of the European siblings, indicating a probable founder effect. Biallelic variants in DNA2 were previously associated with microcephalic osteodysplastic primordial dwarfism. Although the individuals reported here present a similar growth pattern, the presence of poikiloderma and ocular anomalies is unique. Thus, we have broadened the phenotypical spectrum of DNA2 mutations, incorporating clinical characteristics of RTS. Although a clear genotype-phenotype correlation cannot be definitively established at this moment, we speculate that the residual activity of the splicing variant allele could be responsible for the distinct manifestations of DNA2-related syndromes.
- Expanding the Clinical Spectrum of Phenotypes Caused by Pathogenic Variants in PLOD2(2018) LEAL, Gabriela Ferraz; NISHIMURA, Gen; VOSS, Ulrika; BERTOLA, Debora Romeo; ASTROM, Eva; SVENSSON, Johan; YAMAMOTO, Guilherme Lopes; HAMMARSJO, Anna; HOREMUZOVA, Eva; PAPADIOGANNAKIS, Nikos; IWARSSON, Erik; GRIGELIONIENE, Giedre; THAM, EmmaOsteogenesis imperfecta (OI) is a strikingly heterogeneous group of disorders with a broad range of phenotypic variations. It is also one of the differential diagnoses in bent bone dysplasias along with campomelic dysplasia and thanatophoric dysplasia and can usually be distinguished by decreased bone mineralization and bone fractures. Bent bone dysplasias also include syndromes such as kyphomelic dysplasia (MIM:211350) and mesomelic dysplasia Kozlowski-Reardon (MIM249710), both of which have been under debate regarding whether or not they are a real entity or simply a phenotypic manifestation of another dysplasia including OI. Bruck syndrome type 2 (BRKS2; MIM:609220) is a rare form of autosomal recessive OI caused by biallelic PLOD2 variants and is associated with congenital joint contractures with pterygia. In this report, we present six patients from four families with novel PLOD2 variants. All cases had multiple fractures. Other features ranged from prenatal lethal severe angulation of the long bones as in kyphomelic dysplasia and mesomelic dysplasia Kozlowski-Reardon through classical Bruck syndrome to moderate OI with normal joints. Two siblings with a kyphomelic dysplasia-like phenotype who were stillborn had compound heterozygous variants in PLOD2 (p.Asp585Val and p.Ser166*). One infant who succumbed at age 4 months had a bent bone phenotype phenotypically like skeletal dysplasia Kozlowski-Reardon (with mesomelic shortening, camptodactyly, retrognathia, cleft palate, skin dimples, but also with fractures). He was homozygous for the nonsense variant (p.Trp561*). Two siblings had various degrees of Bruck syndrome caused by the homozygous missense variant, p.His687Arg. Furthermore a boy with a clinical presentation of moderate OI had a possibly pathogenic homozygous variant p.Trp588Cys. Our experience of six patients with biallelic pathogenic variants in PLOD2 expands the phenotypic spectrum in the PLOD2-related phenotypes. (c) 2017 American Society for Bone and Mineral Research.
- Burden of Rare Copy Number Variants in Microcephaly: A Brazilian Cohort of 185 Microcephalic Patients and Review of the Literature(2024) TOLEZANO, Giovanna Cantini; BASTOS, Giovanna Civitate; COSTA, Silvia Souza da; FREIRE, Bruna Lucheze; HOMMA, Thais Kataoka; HONJO, Rachel Sayuri; YAMAMOTO, Guilherme Lopes; PASSOS-BUENO, Maria Rita; KOIFFMANN, Celia Priszkulnik; KIM, Chong Ae; VIANNA-MORGANTE, Angela Maria; JORGE, Alexander Augusto de Lima; BERTOLA, Debora Romeo; ROSENBERG, Carla; KREPISCHI, Ana Cristina VictorinoMicrocephaly presents heterogeneous genetic etiology linked to several neurodevelopmental disorders (NDD). Copy number variants (CNVs) are a causal mechanism of microcephaly whose investigation is a crucial step for unraveling its molecular basis. Our purpose was to investigate the burden of rare CNVs in microcephalic individuals and to review genes and CNV syndromes associated with microcephaly. We performed chromosomal microarray analysis (CMA) in 185 Brazilian patients with microcephaly and evaluated microcephalic patients carrying < 200 kb CNVs documented in the DECIPHER database. Additionally, we reviewed known genes and CNV syndromes causally linked to microcephaly through the PubMed, OMIM, DECIPHER, and ClinGen databases. Rare clinically relevant CNVs were detected in 39 out of the 185 Brazilian patients investigated by CMA (21%). In 31 among the 60 DECIPHER patients carrying < 200 kb CNVs, at least one known microcephaly gene was observed. Overall, four gene sets implicated in microcephaly were disclosed: known microcephaly genes; genes with supporting evidence of association with microcephaly; known macrocephaly genes; and novel candidates, including OTUD7A, BBC3, CNTN6, and NAA15. In the review, we compiled 957 known microcephaly genes and 58 genomic CNV loci, comprising 13 duplications and 50 deletions, which have already been associated with clinical findings including microcephaly. We reviewed genes and CNV syndromes previously associated with microcephaly, reinforced the high CMA diagnostic yield for this condition, pinpointed novel candidate loci linked to microcephaly deserving further evaluation, and provided a useful resource for future research on the field of neurodevelopment.
- Germline variants of Brazilian women with breast cancer and detection of a novel pathogenic ATM deletion in early-onset breast cancer(2021) BANDEIRA, Gabriel; ROCHA, Katia; LAZAR, Monize; EZQUINA, Suzana; YAMAMOTO, Guilherme; VARELA, Monica; TAKAHASHI, Vanessa; AGUENA, Meire; GOLLOP, Thomaz; ZATZ, Mayana; PASSOS-BUENO, Maria Rita; KREPISCHI, Ana; OKAMOTO, Oswaldo KeithBackground It is estimated that 5-10% of breast cancer cases are hereditary. The identification of pathogenic germline variants allows individualized preventive health care, improvement of clinical management and genetic counseling. Studies in ethnically admixed Latin American populations have identified regions with increased frequency of deleterious variants in breast cancer predisposing genes. In this context, the Brazilian population exhibits great genetic heterogeneity, and is not well represented in international databases, which makes it difficult to interpret the clinical relevance of germline variants. Methods We evaluated the frequency of pathogenic/likely pathogenic (P/LP) germline variants in up to 37 breast cancer predisposing genes, in a cohort of 105 breast and/or ovarian cancer Brazilian women referred to two research centers between 2014 and 2019. Results A total of 22 patients (21%) were found to carry P/LP variants, and 16 VUS were detected in 15 patients (14.3%). Additionally, a novel pathogenicATMintragenic deletion was identified in an early-onset breast cancer. We also detected aBRCA1pathogenic variant (c.5074+2T>C) in higher frequency (10x) than in other studies with similar cohorts. Conclusions Our findings contribute to the characterization of the genetic background of breast cancer predisposition in the Brazilian population as a useful resource to discriminate between deleterious variants and VUS, thus enabling improvement in the preventive health care and clinical management of carriers.