MIRIAN YUMIE NISHI
Projetos de Pesquisa
Unidades Organizacionais
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies(2015) CORREA, Fernanda A.; TRARBACH, Ericka B.; TUSSET, Cintia; LATRONICO, Ana Claudia; MONTENEGRO, Luciana R.; CARVALHO, Luciani R.; FRANCA, Marcela M.; OTTO, Aline P.; COSTALONGA, Everlayny F.; BRITO, Vinicius N.; ABREU, Ana Paula; NISHI, Mirian Y.; JORGE, Alexander A. L.; ARNHOLD, Ivo J. P.; SIDIS, Yisrael; PITTELOUD, Nelly; MENDONCA, Berenice B.The genetic aetiology of congenital hypopituitarism (CH) is not entirely elucidated. FGFR1 and PROKR2 loss-of-function mutations are classically involved in hypogonadotrophic hypogonadism (HH), however, due to the clinical and genetic overlap of HH and CH; these genes may also be involved in the pathogenesis of CH. Using a candidate gene approach, we screened 156 Brazilian patients with combined pituitary hormone deficiencies (CPHD) for loss-of-function mutations in FGFR1 and PROKR2. We identified three FGFR1 variants (p.Arg448Trp, p.Ser107Leu and p.Pro772Ser) in four unrelated patients (two males) and two PROKR2 variants (p. Arg85Cys and p. Arg248Glu) in two unrelated female patients. Five of the six patients harbouring the variants had a first-degree relative that was an unaffected carrier of it. Results of functional studies indicated that the new FGFR1 variant p.Arg448Trp is a loss-of-function variant, while p.Ser107Leu and p.Pro772Ser present signalling activity similar to the wild-type form. Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca2+ pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity. The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype. The presence of the same variants in unaffected relatives implies that they cannot solely cause the phenotype. Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition.
- Disorders of sex development: effect of molecular diagnostics(2015) ACHERMANN, John C.; DOMENICE, Sorahia; BACHEGA, Tania A. S. S.; NISHI, Mirian Y.; MENDONCA, Berenice B.Disorders of sex development (DSDs) are a diverse group of conditions that can be challenging to diagnose accurately using standard phenotypic and biochemical approaches. Obtaining a specific diagnosis can be important for identifying potentially life-threatening associated disorders, as well as providing information to guide parents in deciding on the most appropriate management for their child. Within the past 5 years, advances in molecular methodologies have helped to identify several novel causes of DSDs; molecular tests to aid diagnosis and genetic counselling have now been adopted into clinical practice. Occasionally, genetic profiling of embryos prior to implantation as an adjunct to assisted reproduction, prenatal diagnosis of at-risk pregnancies and confirmatory testing of positive results found during newborn biochemical screening are performed. Of the available genetic tests, the candidate gene approach is the most popular. New high-throughput DNA analysis could enable a genetic diagnosis to be made when the aetiology is unknown or many differential diagnoses are possible. Nonetheless, concerns exist about the use of genetic tests. For instance, a diagnosis is not always possible even using new molecular approaches (which can be worrying for the parents) and incidental information obtained during the test might cause anxiety. Careful selection of the genetic test indicated for each condition remains important for good clinical practice. The purpose of this Review is to describe advances in molecular biological techniques for diagnosing DSDs.
conferenceObject Mutations in the DHX37 Gene Identified by Whole-Exome Sequencing are a Novel Cause of the Embryonic Testicular Regression Syndrome in Four Families with 46,XY DSD(2015) SILVA, T.; LERARIO, A.; NISHI, M.; FUNARI, M.; DENES, F.; COSTA, E.; MENDONCA, B.; DOMENICE, S.- Pitfalls in hormonal diagnosis of 17-beta hydroxysteroid dehydrogenase III deficiency(2015) KHATTAB, Ahmed; YUEN, Tony; YAU, Mabel; DOMENICE, Sorahia; COSTA, Elaine Maria Frade; DIYA, Kazmi; MUHURI, Dwaipayan; PINA, Christian Enrique; NISHI, Mirian Yumie; YANG, Amy C.; MENDONCA, Berenice Biharinho de; NEW, Maria I.Steroid 17 beta-hydroxysteroid dehydrogenase III (17 beta-HSD3) deficiency is a rare autosomal recessive disorder that usually presents in patients with a 46, XY karyotype with ambiguous genitalia at birth. The 17 beta-HSD3 enzyme, which is encoded by the HSD17B3 gene, converts gonadal delta-4 androstenedione (Delta 4) to testosterone (T). Such 17 beta-HSD3 enzyme deficiency is expected to lead to an increased ratio of D4 to T when the patient undergoes a human chorionic gonadotropin stimulation (hCG) test. Two patients with 46, XY disorders of sexual differentiation were studied. Serum D4 and T levels were measured by HPLC tandem mass spectrometry. As one of the patients was born to consanguineous parents, we performed single nucleotide polymorphism (SNP) microarray to analyze regions of homozygosity (ROH). The HSD17B3 gene was sequenced using the Sanger method. Contrary to expectations, both patients demonstrated decreased D4/T ratio after hCG stimulation. Initial sequencing results for the androgen receptor or 5 alpha-reductase were negative for mutations. ROH analysis identified HSD17B3 as a candidate gene that might cause the disease. Sanger sequencing of the HSD17B3 gene confirmed 17 beta-HSD3 deficiency in both patients. Serum D4/T ratios are not reliable parameters for the diagnosis of 17 beta-HSD3 deficiency. Molecular genetic analysis provides accurate diagnosis.