Tobias Else, Antonio Marcondes Lerario, Jessica Everett, Lori Haymon, Deborah Wham, Michael Mullane, Tremika LeShan Wilson, Irene Rainville, Huma Rana, Andrew J Worth, Nathaniel W Snyder, Ian A Blair, Rana McKay, Kerry Kilbridge, Gary Hammer, Justine Barletta and Anand Vaidya
Germline loss-of-function mutations in succinate dehydrogenase (SDHx) genes results in rare tumor syndromes that include pheochromocytoma, paraganglioma, and others. Here we report a case series of patients with adrenocortical carcinoma (ACC) that harbor SDHx mutations.
Patients and results
We report four unrelated patients with ACC and SDHx mutations. All cases presented with Cushing syndrome and large adrenal masses that were confirmed to be ACC on pathology. All four ACC specimens were found to have truncating mutations in either SDHC or SDHA, while cases 1, 2 and 3 also had the mutations confirmed in the germline: Case 1: SDHC c.397C > T, pR133X; Case 2: SDHC c.43C > T, p.R15X; Case 3: SDHA c.91C > T, p.R31X; Case 4: SDHA c.1258C > T, p.Q420X. Notably, Case 1 had a father and daughter who both harbored the same SDHC germline mutation, and the father had a paraganglioma and renal cell carcinoma. A combination of next generation sequencing, and/or immunohistochemistry, and/or mass spectroscopy was used to determine whether there was loss of heterozygosity and/or loss of SDH protein expression or function within the ACC. Potential evidence of loss of heterozygosity was observed only in Case 2.
We observed truncating mutations in SDHA or SDHC in the ACC and/or germline of four unrelated patients. Given how statistically improbable the concurrence of ACC and pathogenic germline SDHx mutations is expected to be, these observations raise the question whether ACC may be a rare manifestation of SDHx mutation syndromes. Further studies are needed to investigate the possible role of SDH deficiency in ACC pathogenesis.
Lorena Guimaraes Lima Amato, Luciana Ribeiro Montenegro, Antonio Marcondes Lerario, Alexander Augusto Lima Jorge, Gil Guerra Junior, Caroline Schnoll, Alessandra Covallero Renck, Ericka Barbosa Trarbach, Elaine Maria Frade Costa, Berenice Bilharinho Mendonca, Ana Claudia Latronico and Leticia Ferreira Gontijo Silveira
Congenital hypogonadotropic hypogonadism (CHH) is a rare condition caused by GnRH deficiency. Several genes have been associated with the pathogenesis of CHH, but most cases still remain without a molecular diagnosis. The advent of next-generation sequencing (NGS) has allowed the simultaneous genotyping of several regions, faster, making possible the extension of the genetic knowledge of CHH.
Genetic characterization of a large cohort of Brazilian CHH patients.
Design and patients
A cohort of 130 unrelated patients (91 males, 39 females) with CHH (75 normosmic CHH, 55 Kallmann syndrome) was studied using a panel containing 36 CHH-associated genes.
Potential pathogenic or probably pathogenic variants were identified in 43 (33%) CHH patients. The genes ANOS1, FGFR1 and GNRHR were the most frequently affected. A novel homozygous splice site mutation was identified in the GNRH1 gene and a deletion of the entire coding sequence was identified in SOX10. Deleterious variants in the IGSF10 gene were identified in two patients with reversible normosmic CHH. Notably, 6.9% of the patients had rare variants in more than one gene. Rare variants were also identified in SPRY4, IL17RD, FGF17, IGSF1 and FLRT3 genes.
This is a large study of the molecular genetics of CHH providing new genetic findings for this complex and heterogeneous genetic condition. NGS has been shown to be a fast, reliable and effective tool in the molecular diagnosis of congenital CHH and being able to targeting clinical genetic testing in the future.
Edoarda Vasco de Albuquerque Albuquerque, Mariana Ferreira de Assis Funari, Elisângela Pereira de Souza Quedas, Rachel Sayuri Honjo Kawahira, Raquel Soares Jallad, Thaís Kataoka Homma, Regina Matsunaga Martin, Vinicius Nahime Brito, Alexsandra Christianne Malaquias, Antonio Marcondes Lerario, Carla Rosenberg, Ana Cristina Victorino Krepischi, Chong Ae Kim, Ivo Jorge Prado Arnhold and Alexander Augusto de Lima Jorge
Patients with tall stature often remain undiagnosed after clinical investigation and few studies have genetically assessed this group, most of them without a systematic approach.
To assess prospectively a group of individuals with tall stature, with and without syndromic features, and to establish a molecular diagnosis for their growth disorder.
Screening by karyotype (n = 42), chromosome microarray analyses (CMA) (n = 16), MS-MLPA (n = 2) targeted panel (n = 12) and whole-exome sequencing (n = 31).
Patients and methods
We selected 42 patients with tall stature after exclusion of pathologies in GH/IGF1 axis and divided them into syndromic (n = 30) and non-syndromic (n = 12) subgroups.
Main outcome measures
Frequencies of pathogenic findings.
We identified two patients with chromosomal abnormalities including SHOX trisomy by karyotype, one 9q22.3 microdeletion syndrome by CMA, two cases of Beckwith–Wiedemann syndrome by targeted MS-MLPA analysis and nine cases with heterozygous pathogenic or likely pathogenic genetic variants by multigene analysis techniques (FBN1 = 3, NSD1 = 2, NFIX = 1, SUZ12 = 1, CHD8 = 1, MC4R = 1). Three of 20 patients analyzed by WES had their diagnosis established. Only one non-syndromic patient had a definitive diagnosis. The sequential genetic assessment diagnosed 14 out of 42 (33.3%) tall patients.
A systematic molecular approach of patients with tall stature was able to identify the etiology in 13 out of 30 (43.3%) syndromic and 1 out of 12 (8.3%) non-syndromic patients, contributing to the genetic counseling and avoiding unfavorable outcomes in the syndromic subgroup.