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
5 resultados
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- 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.
- 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.
- Phenotype-genotype analysis of 242 individuals with RASopathies: 18-year experience of a tertiary center in Brazil(2020) BERTOLA, Debora R.; CASTRO, Matheus A. A.; YAMAMOTO, Guilherme L.; HONJO, Rachel S.; CERONI, Jose Ricardo; BUSCARILLI, Michele M.; FREITAS, Amanda B.; MALAQUIAS, Alexsandra C.; PEREIRA, Alexandre C.; JORGE, Alexander A. L.; PASSOS-BUENO, Maria Rita; KIM, Chong A.We report the clinical and molecular data of a large cohort comprising 242 individuals with RASopathies, from a single Tertiary Center in Brazil, the largest study from Latin America. Noonan syndrome represented 76% of the subjects, with heterozygous variants in nine different genes, mainly PTPN11, SOS1, RAF1, LZTR1, and RIT1, detected by Sanger and next-generation sequencing. The latter was applied to 126 individuals, with a positive yield of 63% in genes of the RAS/MAPK cascade. We present evidence that there are some allelic differences in PTPN11 across distinct populations. We highlight the clinical aspects that pose more medical concerns, such as the cardiac anomalies, bleeding diathesis and proliferative lesions. The genotype-phenotype analysis between the RASopathies showed statistically significant differences in some cardinal features, such as craniofacial and cardiac anomalies, the latter also statistically significant for different genes in Noonan syndrome. We present two individuals with a Noonan syndrome phenotype, one with an atypical, structural cardiac defect, harboring variants in genes mainly associated with isolated hypertrophic cardiomyopathy and discuss the role of these variants in their phenotype.
- Large deletion in PIGL: a common mutational mechanism in CHIME syndrome?(2018) CERONI, Jose R. M.; YAMAMOTO, Guilherme L.; HONJO, Rachel S.; KIM, Chong A.; PASSOS-BUENO, Maria R.; BERTOLA, Debora R.CHIME syndrome is an extremely rare autosomal recessive multisystemic disorder caused by mutations in PIGL. PIGL is an endoplasmic reticulum localized enzyme that catalyzes the second step of glycosylphosphatidylinositol (GPI) biosynthesis, which plays a role in the anchorage of cell-surface proteins including receptors, enzymes, and adhesion molecules. Germline mutations in other members of GPI and Post GPI Attachment to Proteins (PGAP) family genes have been described and constitute a group of diseases within the congenital disorders of glycosylation. Patients in this group often present alkaline phosphatase serum levels abnormalities and neurological symptoms. We report a CHIME syndrome patient who harbors a missense mutation c.500T > C (p.Leu167Pro) and a large deletion involving the 5' untranslated region and part of exon 1 of PIGL. In CHIME syndrome, a recurrent missense mutation c.500T > C (p.Leu167Pro) is found in the majority of patients, associated with a null mutation in the other allele, including an overrepresentation of large deletions. The latter are not detected by the standard analysis in sequencing techniques, including next-generation sequencing. Thus, in individuals with a clinical diagnosis of CHIME syndrome in which only one mutation is found, an active search for a large deletion should be sought.
conferenceObject Overlapping phenotypes in patients harboring heterozygous mutations in KAT6A and KAT6B(2019) ESTRELLA, S.; BERTOLA, D.; YAMAMOTO, G. L.; HONJO, R.; CERONI, J. R.; KIM, C. A.