Iodothyronine deiodinases and reduced sensitivity to thyroid hormones.

Iodothyronine deiodinases are selenoproteins that regulate thyroid hormone metabolism. Of the three types of deiodinases, type 2 is the major regulator of intracellular triiodothyronine concentration in both the hypothalamus and pituitary, and therefore the major regulator of thyrotropin secretion. A defect in iodothyronine deiodinase activity can lead to a reduced sensitivity to thyroid hormones action and the most recent literature includes these defects in the so-called "syndromes of reduced sensitivity to thyroid hormones". To date, the pathogenic variants of the selenocysteine insertion sequence-binding protein 2 (SECISBP2) gene are the first and only inherited disorder of iodothyronine metabolism described. Moreover, there is a growing interest in understanding the possible role of polymorphisms of DIO1 and DIO2 genes in some pathological conditions and in determining the requirement of levothyroxine replacement and the role of combined levothyroxine-liothyronine therapy in carrying subjects affected by hypothyroidism and who need replacement therapy. Results on this topic are still conflicting and more studies are needed to assess the efficacy of combined levothyroxine-liothyronine replacement therapy in this subset of patients

Insight into a Novel p53 Single Point Mutation (G389E) by Molecular Dynamics Simulations

The majority of inactivating mutations of p53 reside in the central core DNA binding domain of the protein. In this computational study, we investigated the structural effects of a novel p53 mutation (G389E), identified in a patient with congenital adrenal hyperplasia, which is located within the extreme C-terminal domain (CTD) of p53, an unstructured, flexible region (residues 367–393) of major importance for the regulation of the protein. Based on the three-dimensional structure of a carboxyl-terminal peptide of p53 in complex with the S100B protein, which is involved in regulation of the tumor suppressor activity, a model of wild type (WT) and mutant extreme CTD was developed by molecular modeling and molecular dynamics simulation. It was found that the G389E amino acid replacement has negligible effects on free p53 in solution whereas it significantly affects the interactions of p53 with the S100B protein. The results suggest that the observed mutation may interfere with p53 transcription activation and provide useful information for site-directed mutagenesis experiments

A new CYP21A1P/CYP21A2 chimeric gene identified in an Italian woman suffering from classical congenital adrenal hyperplasia form

Background: More than 90% of Congenital Adrenal Hyperplasia (CAH) cases are associated with mutations in the 21-hydroxylase gene (CYP21A2) in the HLA class III area on the short arm of chromosome 6p21.3. In this region, a 30 kb deletion produces a non functional chimeric gene with its 5′ and 3′ ends corresponding to CYP21A1P pseudogene and CYP21A2, respectively. To date, five different CYP21A1P/CYP21A2 chimeric genes have been found and characterized in recent studies. In this paper, we describe a new CYP21A1P/CYP21A2 chimera (CH-6) found in an Italian CAH patient. Methods Southern blot analysis and CYP21A2 sequencing were performed on the patient. In addition, in order to isolate the new CH-6 chimeric gene, two different strategies were used. Results: The CYP21A2 sequencing analysis showed that the patient was homozygote for the g.655C/A<G mutation and heterozygote for the p.P30L missense mutation. In addition, the promoter sequence revealed the presence, in heterozygosis, of 13 SNPs generally produced by microconversion events between gene and pseudogene. Southern blot analysis showed that the woman was heterozygote for the classic 30-kb deletion producing a new CYP21A1P/CYP21A2 chimeric gene (CH-6). The hybrid junction site was located between the end of intron 2 pseudogene, after the g.656C/A<G mutation, and the beginning of exon 3, before the 8 bp deletion. Consequently, CH-6 carries three mutations: the weak pseudogene promoter region, the p.P30L and the g.655C/A<G splice mutation. Conclusion: We describe a new CYP21A1P/CYP21A2 chimera (CH-6), associated with the HLA-B15, DR13 haplotype, in a young Italian CAH patient. © 2009 Concolino et al; licensee BioMed Central Ltd

BRCA Mutation Status in Triple-Negative Breast Cancer Patients Treated with Neoadjuvant Chemotherapy: A Pivotal Role for Treatment Decision-Making

Simple Summary In this retrospective observational study, we evaluated data from patients with triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NACT) in order to better define the impact of germline BRCA1/2 (gBRCA1/2) mutation status on outcomes in this patient population. Our results show that patients with BRCA1/2 mutation had a higher pathologic complete response (pCR) rate than non-mutated patients; nevertheless, the benefit was confirmed only in the subset of patients who received a platinum-based NACT. Furthermore, pCR was associated with improved Event Free Survival (EFS) and Overall Survival (OS), regardless of BRCA1/2 mutation status and type of NACT received. Long-term follow-up analyses are needed to further define the impact of gBRCA mutation status in patients with early-TNBC. Triple-negative breast cancer (TNBC) is characterized by earlier recurrence and shorter survival compared with other types of breast cancer. Moreover, approximately 15 to 25% of all TNBC patients harbor germline BRCA (gBRCA) 1/2 mutations, which confer a more aggressive phenotype. However, TNBC seems to be particularly sensitive to chemotherapy, the so-called 'triple negative paradox'. Therefore, Neoadjuvant chemotherapy (NACT) is currently considered the preferred approach for early-stage TNBC. BRCA status has also been studied as a predictive biomarker of response to platinum compounds. Although several randomized trials investigated the addition of carboplatin to standard NACT in early-stage TNBC, the role of BRCA status remains unclear. In this retrospective analysis, we evaluated data from 136 consecutive patients with Stage I-III TNBC who received standard NACT with or without the addition of carboplatin, in order to define clinical features and outcomes in BRCA 1/2 mutation carriers and non-carrier controls. Between January 2013 and February 2021, 67 (51.3%) out of 136 patients received a standard anthracyclines/taxane regimen and 69 (50.7%) patients received a platinum-containing chemotherapy regimen. Deleterious germline BRCA1 or BRCA2 mutations were identified in 39 (28.7%) patients. Overall, patients with deleterious gBRCA1/2 mutation have significantly higher pCR rate than non-carrier patients (23 [59%] of 39 vs. 33 [34%] of 97; p = 0.008). The benefit of harboring a gBRCA mutation was confirmed only in the subset of patients who received a platinum-based NACT (17 [65.4%] of 26 vs. 13 [30.2%] of 43; p = 0.005) while no differences were found in the platinum-free subgroup. Patients who achieved pCR after NACT had significantly better EFS (OR 4.5; 95% CI 1.9-10.7; p = 0.001) and OS (OR 3.3; 95% CI 1.3-8.9; p = 0.01) than patients who did not, regardless of BRCA1/2 mutation status and type of NACT received. Our results based on real-world evidence show that TNBC patients with the gBRCA1/2 mutation who received platinum-based NACT have a higher pCR rate than non-carrier patients, supporting the use of this chemotherapy regimen in this patient population. Long-term follow-up analyses are needed to further define the role of gBRCA mutation status on clinical outcomes in patients with early-TNBC

Large scale multifactorial likelihood quantitative analysis of BRCA1 and BRCA2 variants: An ENIGMA resource to support clinical variant classification

The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared with information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known nonpathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification

Large scale multifactorial likelihood quantitative analysis of BRCA1 and BRCA2 variants: An ENIGMA resource to support clinical variant classification

Abstract The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared to information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known non-pathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification. This article is protected by copyright. All rights reserved.Peer reviewe

Genes, pseudogenes and like genes: The case of 21-hydroxylase in Italian population

Backgrounds: Recently, we have considered two new findings in genetics of 21-hydroxylase deficiency with great interested: the existence of rare RCCX trimodular haplotypes, where the CYP21A2 like-gene downstream of the TNXA gene carries from one to six pseudogene mutations, and population specific allelic frequencies of wild-type CYP21A2 loci in the CYP21A1P pseudogene. Both these events represent a further complication in CYP21A2 genetics. Therefore, the choice of the molecular protocol becomes a crucial point when genetic analysis is required. In this regard, we must consider that the literature is still lacking consistent data on the Italian population. For this reason, we report genetic results obtained on 375 healthy individuals of Italian origin. Methods: Different genetic protocols were compared and novel molecular strategies were performed. Results: In our group, only two known haplotypes were identified. In addition, specific allelic frequencies of CYP21A2 wild-type loci in the pseudogene have been established. Conclusions: Based on our results, we can affirm that the employment of different molecular methods is necessary to ensure a correct CYP21A2 genotyping. In order to avoid mistakes both in patient diagnosis and/or in risk evaluation of the relatives, each case should be investigated in function of a careful clinical evaluation and the molecular test should be performed in specialized centres. (c) 2013 The Authors. Published by Elsevier B.V. All rights reserved

Multiple endocrine neoplasia type 1 (MEN1): An update of 208 new germline variants reported in the last nine years

This review will focus on the germline MEN1 mutations that have been reported in patients with MEN1 and other hereditary endocrine disorders from 2007 to September 2015. A comprehensive review regarding the analysis of 1336 MEN1 mutations reported in the first decade following the gene's identification was performed by Lemos and Thakker in 2008. No other similar papers are available in literature apart from these data. We also checked for the list of Locus-Specific DataBases (LSDBs) and we found five MEN1 free-online mutational databases. 151 articles from the NCBI PubMed literature database were read and evaluated and a total of 75 MEN1 variants were found. On the contrary, 67, 22 and 44 novel MEN1 variants were obtained from ClinVar, MEN1 at Caf Variome and HGMD (The Human Gene Mutation Database) databases respectively. A final careful analysis of MEN1 mutations affecting the coding region was performed