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
14 resultados
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- 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.
- Vertebral segmentation defects in a Brazilian cohort: Clinical and molecular analysis focused on spondylocostal dysostosis(2022) LINNENKAMP, Bianca; GIRARDI, Raissa; ROCHA, Leticia; YAMAMOTO, Guilherme; CERONI, Jose Ricardo; MENDES, Antonia Elisabeth Cristhina; HONJO, Rachel; OLIVEIRA, Luiz Antonio; AMEMIYA, Raphael Bruno; QUAIO, Caio; OLIVEIRA FILHO, Joao Bosco de; KIM, Chong Ae; BERTOLA, Debora
- Autosomal-Recessive Mutations in MESD Cause Osteogenesis Imperfecta(2019) MOOSA, Shahida; YAMAMOTO, Guilherme L.; GARBES, Lutz; KEUPP, Katharina; BELEZA-MEIRELES, Ana; MORENO, Carolina Araujo; VALADARES, Eugenia Ribeiro; SOUSA, Sergio B. de; MAIA, Sofia; SARAIVA, Jorge; HONJO, Rachel S.; KIM, Chong Ae; MENEZES, Hamilton Cabral de; LAUSCH, Ekkehart; LORINI, Pablo Villavicencio; LAMOUNIER JR., Arsonval; CARNIERO, Tulio Canella Bezerra; GIUNTA, Cecilia; ROHRBACH, Marianne; JANNER, Marco; SEMLER, Oliver; BELEGGIA, Filippo; LI, Yun; YIGIT, Goekhan; REINTJES, Nadine; ALTMUELLER, Janine; NUERNBERG, Peter; CAVALCANTI, Denise P.; ZABEL, Bernhard; WARMAN, Matthew L.; BERTOLA, Debora R.; WOLLNIK, Bernd; NETZER, ChristianOsteogenesis imperfecta (OI) comprises a genetically heterogeneous group of skeletal fragility diseases. Here, we report on five independent families with a progressively deforming type of OI, in whom we identified four homozygous truncation or frameshift mutations in MESD. Affected individuals had recurrent fractures and at least one had oligodontia. MESD encodes an endoplasmic reticulum (ER) chaperone protein for the canonical Wingless-related integration site (WNT) signaling receptors LRP5 and LRP6. Because complete absence of MESD causes embryonic lethality in mice, we hypothesized that the OI-associated mutations are hypomorphic alleles since these mutations occur downstream of the chaperone activity domain but upstream of ER-retention domain. This would be consistent with the clinical phenotypes of skeletal fragility and oligodontia in persons deficient for LRP5 and LRP6, respectively. When we expressed wild-type (WT) and mutant MESD in HEK293T cells, we detected WT MESD in cell lysate but not in conditioned medium, whereas the converse was true for mutant MESD. We observed that both WT and mutant MESD retained the ability to chaperone LRP5. Thus, 01-associated MESD mutations produce hypomorphic alleles whose failure to remain within the ER significantly reduces but does not completely eliminate LRP5 and LRP6 trafficking. Since these individuals have no eye abnormalities (which occur in individuals completely lacking LRP5) and have neither limb nor brain patterning defects (both of which occur in mice completely lacking LRP6), we infer that bone mass accrual and dental patterning are more sensitive to reduced canonical WNT signaling than are other developmental processes. Biologic agents that can increase LRP5 and LRP6-mediated WNT signaling could benefit individuals with MESD-associated OI.
- Intragenic Deletion in the LIFR Gene in a Long-Term Survivor with Stuve-Wiedemann Syndrome(2015) MARQUES, Julia Hatagami; YAMAMOTO, Guilherme Lopes; TESTAI, Larissa de Cassia; PEREIRA, Alexandre da Costa; KIM, Chong Ae; PASSOS-BUENO, Maria R.; BERTOLA, Debora RomeoStuve-Wiedemann syndrome (SWS, OMIM 601559) is a rare autosomal recessive bent-bone dysplasia, caused by loss-offunction mutations in the leukemia inhibitory factor receptor (LIFR) gene, which usually leads to early death. Only few patients with long-term survival have been described in the literature. We report on a 5-year-old boy from a consanguineous marriage with molecular analysis for the LIFR gene. Sanger and next-generation sequencing (NGS) of LIFR were performed. Copy number variation analysis with NGS showed a novel mutation as the cause for the syndrome: an intragenic homozygous deletion in LIFR, involving exons 1520. Bridging PCR was carried out to confirm the intragenic deletion. This is the first description of a large deletion in LIFR, broadening the spectrum of mutations in SWS. Besides the reported allelic heterogeneity, further studies such as exome sequencing are required to identify a novel gene in order to confirm the locus heterogeneity in SWS. (C) 2015 S. Karger AG, Basel
- The recurrent homozygous translation start site variant in CCDC134 in an individual with severe osteogenesis imperfecta of non-Morrocan ancestry(2022) ALI, Taccyanna M.; LINNENKAMP, Bianca D. W.; YAMAMOTO, Guilherme L.; HONJO, Rachel S.; MENEZES FILHO, Hamilton Cabral de; KIM, Chong Ae; BERTOLA, Debora R.Osteogenesis imperfecta (OI) is a rare low-bone mass skeletal Mendelian disorder characterized by bone fragility leading to bone fractures, with deformities and stunted growth in the more severe phenotypes. Other common, nonskeletal findings include blue sclerae and dentinogenesis imperfecta. It is caused mainly by quantitative or structural defects in type I collagen, although dysregulation of different signaling pathways that play a role in bone morphogenesis has been described to be associated with a small fraction of individuals with OI. Recently, a homozygous variant in the translation start site of CCDC134, showing increased activation of the RAS/MAPK signaling pathway, has been reported in three families of Moroccan origin with a severe, deforming form of OI. We report on a 9-year-old Brazilian boy, harboring the same homozygous variant in CCDC134, also presenting severe bone involvement. This report contributes to the phenotypic delineation of this novel autosomal recessive form of OI, which presents with high prevalence of nonunion fractures considered rare events in OI in general. In addition, it expands the phenotype to include base skull anomalies, potentially leading to serious complications, as seen in severe forms of OI. A poor response to bisphosphonate therapy was observed in these individuals. As the variant in CCDC134 leads to dysregulation of the RAS/MAPK signaling pathway, drugs targeted to this pathway could be an alternative to achieve a better management of these individuals.
- Congenital limb deficiency: Genetic investigation of 44 individuals presenting mainly longitudinal defects in isolated or syndromic forms(2021) ROCHA, Leticia Alves da; PIRES, Lucas Vieira Lacerda; YAMAMOTO, Guilherme Lopes; CERONI, Jose Ricardo Magliocco; HONJO, Rachel Sayuri; BISNETO, Edgard de Novaes Franca; OLIVEIRA, Luiz Antonio Nunes; ROSENBERG, Carla; KREPISCHI, Ana Cristina Victorino; PASSOS-BUENO, Maria Rita; KIM, Chong Ae; BERTOLA, Debora RomeoCongenital limb deficiency (CLD), one of the most common congenital anomalies, is characterized by hypoplasia/aplasia of one or more limb bones and can be isolated or syndromic. The etiology in CLD is heterogeneous, including environmental and genetic factors. A fraction remains with no etiological factor identified. We report the study of 44 Brazilian individuals presenting isolated or syndromic CLD, mainly with longitudinal defects. Genetic investigation included particularly next-generation sequencing (NGS) and/or chromosomal microarray. The overall diagnostic yield was 45.7%, ranging from 60.9% in the syndromic to 16.7% in the non-syndromic group. In TAR syndrome, a common variant in 3 ' UTR of RBM8A, in trans with 1q21.1 microdeletion, was detected, corroborating the importance of this recently reported variant in individuals of African ancestry. NGS established a diagnosis in three individuals in syndromes recently reported or still under delineation (an acrofacial dysostosis, Coats plus and Verheij syndromes), suggesting a broader phenotypic spectrum in these disorders. Although a low rate of molecular detection in non-syndromic forms was observed, it is still possible that variants in non-coding regions and small CNVs, not detected by the techniques applied in this study, could play a role in the etiology of CLD.
- 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.
- Post-mortem cytogenomic investigations in patients with congenital malformations(2016) DIAS, Alexandre Torchio; ZANARDO, Evelin Aline; DUTRA, Roberta Lelis; PIAZZON, Flavia Balbo; NOVO-FILHO, Gil Monteiro; MONTENEGRO, Marilia Moreira; NASCIMENTO, Amom Mendes; ROCHA, Mariana; MADIA, Fabricia Andreia Rosa; COSTA, Thais Virginia Moura Machado; MILANI, Cintia; SCHULTZ, Regina; GONCALVES, Fernanda Toledo; FRIDMAN, Cintia; YAMAMOTO, Guilherme Lopes; BERTOLA, Debora Romeo; KIM, Chong Ae; KULIKOWSKI, Leslie DomeniciCongenital anomalies are the second highest cause of infant deaths, and, in most cases, diagnosis is a challenge. In this study, we characterize patterns of DNA copy number aberrations in different samples of post-mortem tissues from patients with congenital malformations. Twenty-eight patients undergoing autopsy were cytogenomically evaluated using several methods, specifically, Multiplex Ligation-dependent Probe Amplification (MLPA), micro satellite marker analysis with a MiniFiler kit, FISH, a cytogenomic array technique and bidirectional Sanger sequencing, which were performed on samples of different tissues (brain, heart, liver, skin and diaphragm) preserved in RNAlater, in formaldehyde or by paraffin -embedding. The results identified 13 patients with pathogenic copy number variations (CNVs). Of these, eight presented aneuploidies involving chromosomes 13, 18, 21, X and Y (two presented inter- and intra-tissue mosaicism). In addition, other abnormalities were found, including duplication of the TYMS gene (18p1132); deletion of the CHL1 gene (3p26.3); deletion of the HIC1 gene (17p13.3); and deletion of the TOM1L2 gene (17p11.2). One patient had a pathogenic missense mutation of g.8535C > G (c.746C > G) in exon 7 of the FGFR3 gene consistent with Thanatophoric Dysplasia type I. Cytogenomic techniques were reliable for the analysis of autopsy material and allowed the identification of inter- and intra-tissue mosaicism and a better understanding of the pathogenesis of congenital malformations.
- Atypical, severe hypertrophic cardiomyopathy in a newborn presenting Noonan syndrome harboring a recurrent heterozygous MRAS variant(2021) PIRES, Lucas Vieira Lacerda; BORDIM, Renata de Almeida; MACIEL, Maria Beatriz Rabelo; TANAKA, Ana Cristina Sayuri; YAMAMOTO, Guilherme Lopes; HONJO, Rachel Sayuri; KIM, Chong Ae; BERTOLA, Debora RomeoNoonan syndrome (NS) is a Mendelian phenotype, member of a group of disorders sharing neurocardiofaciocutaneous involvement, known as RASopathies, caused by germline variants in genes coding for components of the RAS/MAPK signaling pathway. Recently, a novel gene of the RAS family (MRAS) was reported to be associated with NS in five children, all of them presenting, among the cardinal features of NS, the same cardiac finding, hypertrophic cardiomyopathy (HCM). We report on a 2-month-old infant boy also presenting this cardiac anomaly that evolved to a fatal outcome after a surgical myectomy. In addition, a thick walled left ventricle apical aneurysm, rarely described in NS, was also disclosed. Next-generation sequencing revealed a missense, previously reported variant in MRAS (p.Thr68Ile). This report reinforces the high frequency of HCM among individuals harboring MRAS variants, contrasting to the 20% overall prevalence of this cardiac anomaly in NS. Thus, these preliminary data suggest that variants in MRAS per se are high risk factors for the development of an early, severe HCM, mostly of them with left ventricle outflow tract obstruction, with poor prognosis. Because of the severity of the cardiac involvement, other clinical findings could not be addressed in detail. Therefore, long-term follow-up of these individuals and further descriptions are required to fully understand the complete phenotypic spectrum of NS associated with MRAS germline variants, including if these individuals present an increased risk for cancer.