IVO JORGE PRADO ARNHOLD
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina - Líder
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conferenceObject RESPONSE TO RHGH THERAPY IN SHORT CHILDREN BORN AT VERY LOW BIRTH WEIGHT(2023) MALAQUIAS, A. C.; HOMMA, T.; DANTAS, M. C. B.; FREIRE, B. L.; ALBUQUE, E. V. A.; ARNHOLD, I. J. P.; VASQUES, G. A.; JORGE, A. A. L.conferenceObject p.Gln207Arg GH1 allelic variant associated to GH deficiency and specific intronic region may be a modulator of GH secretion(2023) SASSON, Tessa; DAUBER, Andrew; JORGE, Alexander; PANDEY, Amit; ARNHOLD, Ivo; CARVALHO, Luciani- Homozygous CDH2 variant may be associated with hypopituitarism without neurological disorders(2023) FERREIRA, Nathalia G. B. P.; MADEIRA, Joao L. O.; GERGICS, Peter; KERTSZ, Renata; MARQUES, Juliana M.; TRIGUEIRO, Nicholas S. S.; BENEDETTI, Anna Flavia Figueredo; V, Bruna Azevedo; V, Bianca H. Fernandes; BISSEGATTO, Debora D.; BISCOTTO, Isabela P.; FANG, Qing; MA, Qianyi; OZEL, Asye B.; LI, Jun; CAMPER, Sally A.; JORGE, Alexander A. L.; MENDONCA, Berenice B.; ARNHOLD, Ivo J. P.; CARVALHO, Luciani R.Context: Congenital hypopituitarism is a genetically heterogeneous condition. Whole exome sequencing (WES) is a promising approach for molecular diagnosis of patients with this condition. Objectives: The aim of this study is to conduct WES in a patient with congenital hypopituitarism born to consanguineous parents, CDH2 screening in a cohort of patients with congenital hypopituitarism, and functional testing of a no vel CDH2 variant. Design: Genomic DNA from a proband and her consanguineous parents was analyzed by WES. Copy number variants were evaluated. The genetic variants were filtered for population frequency (ExAC, 1000 genomes, gnomAD, and ABraOM), in silico prediction of pathogenicity, and gene expression in the pituitary and/or hypothalamus. Genomic DNA from 145 patients was screened for CDH2 by Sanger sequencing. Results: One female patient with deficiencies in growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, and follicle-stimulating hormone and ectopic posterior pituitary gland contained a rare homozygous c.865G>A (p.Val289Ile) variant in CDH2. To determine whether the p.Val289Ile variant in CDH2 affects cell adhesion properties, we stably transfected L1 fibroblast lines, labeled the cells with lipophilic dyes, and quantified aggregation. Large aggregates formed in cells expressing wildtype CDH2, but aggregation was impaired in cells transfected with variant CDH2 or non-transfected. Conclusion: A homozygous CDH2 allelic variant was found in one hypopituitarism patient, and the variant impaired cell aggregation function in vitro. No disease-causing variants were found in 145 other patients screened for CDH2 variants. Thus, CDH2 is a candidate gene for hypopituitarism that needs to be tested in different populations.
- Identification of a second genetic alteration in patients with SHOX deficiency individuals: a potential explanation for phenotype variability(2023) DANTAS, Naiara C. B.; FUNARI, Mariana F. A.; LERARIO, Antonio M.; ANDRADE, Nathalia L. M.; REZENDE, Raissa C.; CELLIN, Laurana P.; ALVES, Cresio; CRISOSTOMO, Lindiane G.; ARNHOLD, Ivo J. P.; MENDONCA, Berenice; SCALCO, Renata C.; JORGE, Alexander A. L.Objective Our study aimed to assess the impact of genetic modifiers on the significant variation in phenotype that is observed in individuals with SHOX deficiency, which is the most prevalent monogenic cause of short stature.Design and methods We performed a genetic analysis in 98 individuals from 48 families with SHOX deficiency with a target panel designed to capture the entire SHOX genomic region and 114 other genes that modulate growth and/or SHOX action. We prioritized rare potentially deleterious variants.Results We did not identify potential deleterious variants in the promoter or intronic regions of the SHOX genomic locus. In contrast, we found eight heterozygous variants in 11 individuals from nine families in genes with a potential role as genetic modifiers. In addition to a previously described likely pathogenic (LP) variant in CYP26C1 observed in two families, we identified LP variants in PTHLH and ACAN, and variants of uncertain significance in NPR2, RUNX2, and TP53 in more affected individuals from families with SHOX deficiency. Families with a SHOX alteration restricted to the regulatory region had a higher prevalence of a second likely pathogenic variant (27%) than families with an alteration compromising the SHOX coding region (2.9%, P = .04).Conclusion In conclusion, variants in genes related to the growth plate have a potential role as genetic modifiers of the phenotype in individuals with SHOX deficiency. In individuals with SHOX alterations restricted to the regulatory region, a second alteration could be critical to determine the penetrance and expression of the phenotype.