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Ramos RM, Petroli RJ, D'Alessandre NDR, Guardia GDA, Afonso ACDF, Nishi MY, Domenice S, Galante PAF, Mendonca BB, Batista RL. Small Indels in the Androgen Receptor Gene: Phenotype Implications and Mechanisms of Mutagenesis. J Clin Endocrinol Metab 2023; 109:68-79. [PMID: 37572362 DOI: 10.1210/clinem/dgad470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/02/2023] [Accepted: 08/07/2023] [Indexed: 08/14/2023]
Abstract
CONTEXT Despite high abundance of small indels in human genomes, their precise roles and underlying mechanisms of mutagenesis in Mendelian disorders require further investigation. OBJECTIVE To profile the distribution, functional implications, and mechanisms of small indels in the androgen receptor (AR) gene in individuals with androgen insensitivity syndrome (AIS). METHODS We conducted a systematic review of previously reported indels within the coding region of the AR gene, including 3 novel indels. Distribution throughout the AR coding region was examined and compared with genomic population data. Additionally, we assessed their impact on the AIS phenotype and investigated potential mechanisms driving their occurrence. RESULTS A total of 82 indels in AIS were included. Notably, all frameshift indels exhibited complete AIS. The distribution of indels across the AR gene showed a predominance in the N-terminal domain, most leading to frameshift mutations. Small deletions accounted for 59.7%. Most indels occurred in nonrepetitive sequences, with 15.8% situated within triplet regions. Gene burden analysis demonstrated significant enrichment of frameshift indels in AIS compared with controls (P < .00001), and deletions were overrepresented in AIS (P < .00001). CONCLUSION Our findings underscore a robust genotype-phenotype relationship regarding small indels in the AR gene in AIS, with a vast majority presenting complete AIS. Triplet regions and homopolymeric runs emerged as prone loci for small indels within the AR. Most were frameshift indels, with polymerase slippage potentially explaining half of AR indel occurrences. Complex frameshift indels exhibited association with palindromic runs. These discoveries advance understanding of the genetic basis of AIS and shed light on potential mechanisms underlying pathogenic small indel events.
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Affiliation(s)
- Raquel Martinez Ramos
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
| | - Reginaldo José Petroli
- Faculdade de Medicina da Universidade Federal de Alagoas (UFAL), Programa de Pós-Graduação em Ciências Médicas-UFAL, Maceió, AL, 57072-900, Brazil
| | | | | | - Ana Caroline de Freitas Afonso
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
| | - Mirian Yumie Nishi
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
| | - Sorahia Domenice
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
| | | | - Berenice Bilharinho Mendonca
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
| | - Rafael Loch Batista
- Developmental Endocrinology Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Internal Medicine Department, Medical School, University of São Paulo (USP), São Paulo, SP, 05403-000, Brazil
- Instituto do Câncer do Estado de São Paulo da Faculdade, de Medicina da Universidade de São Paulo (ICESP), São Paulo, SP, 01246-000, Brazil
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Lanciotti L, Cofini M, Leonardi A, Bertozzi M, Penta L, Esposito S. Different Clinical Presentations and Management in Complete Androgen Insensitivity Syndrome (CAIS). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16071268. [PMID: 30970592 PMCID: PMC6480640 DOI: 10.3390/ijerph16071268] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/01/2019] [Accepted: 04/04/2019] [Indexed: 01/08/2023]
Abstract
Complete androgen insensitivity syndrome (CAIS) is an X-linked recessive genetic disorder resulting from maternally inherited or de novo mutations involving the androgen receptor gene, situated in the Xq11-q12 region. The diagnosis is based on the presence of female external genitalia in a 46, XY human individual, with normally developed but undescended testes and complete unresponsiveness of target tissues to androgens. Subsequently, pelvic ultrasound or magnetic resonance imaging (MRI) could be helpful in confirming the absence of Mullerian structures, revealing the presence of a blind-ending vagina and identifying testes. CAIS management still represents a unique challenge throughout childhood and adolescence, particularly regarding timing of gonadectomy, type of hormonal therapy, and psychological concerns. Indeed this condition is associated with an increased risk of testicular germ cell tumour (TGCT), although TGCT results less frequently than in other disorders of sex development (DSD). Furthermore, the majority of detected tumoral lesions are non-invasive and with a low probability of progression into aggressive forms. Therefore, histological, epidemiological, and prognostic features of testicular cancer in CAIS allow postponing of the gonadectomy until after pubertal age in order to guarantee the initial spontaneous pubertal development and avoid the necessity of hormonal replacement therapy (HRT) induction. However, HRT is necessary after gonadectomy in order to prevent symptoms of hypoestrogenism and to maintain secondary sexual features. This article presents differential clinical presentations and management in patients with CAIS to emphasize the continued importance of standardizing the clinical and surgical approach to this disorder.
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Affiliation(s)
- Lucia Lanciotti
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, 06132 Perugia, Italy.
| | - Marta Cofini
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, 06132 Perugia, Italy.
| | - Alberto Leonardi
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, 06132 Perugia, Italy.
| | - Mirko Bertozzi
- Pediatric Surgery, Azienda Ospedaliera Santa Maria della Misericordia, 20122 Perugia, Italy.
| | - Laura Penta
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, 06132 Perugia, Italy.
| | - Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, 06132 Perugia, Italy.
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Parivesh A, Barseghyan H, Délot E, Vilain E. Translating genomics to the clinical diagnosis of disorders/differences of sex development. Curr Top Dev Biol 2019; 134:317-375. [PMID: 30999980 PMCID: PMC7382024 DOI: 10.1016/bs.ctdb.2019.01.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The medical and psychosocial challenges faced by patients living with Disorders/Differences of Sex Development (DSD) and their families can be alleviated by a rapid and accurate diagnostic process. Clinical diagnosis of DSD is limited by a lack of standardization of anatomical and endocrine phenotyping and genetic testing, as well as poor genotype/phenotype correlation. Historically, DSD genes have been identified through positional cloning of disease-associated variants segregating in families and validation of candidates in animal and in vitro modeling of variant pathogenicity. Owing to the complexity of conditions grouped under DSD, genome-wide scanning methods are better suited for identifying disease causing gene variant(s) and providing a clinical diagnosis. Here, we review a number of established genomic tools (karyotyping, chromosomal microarrays and exome sequencing) used in clinic for DSD diagnosis, as well as emerging genomic technologies such as whole-genome (short-read) sequencing, long-read sequencing, and optical mapping used for novel DSD gene discovery. These, together with gene expression and epigenetic studies can potentiate the clinical diagnosis of DSD diagnostic rates and enhance the outcomes for patients and families.
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Affiliation(s)
- Abhinav Parivesh
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States
| | - Hayk Barseghyan
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States
| | - Emmanuèle Délot
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States.
| | - Eric Vilain
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States.
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Ledig S, Jakubiczka S, Neulen J, Aulepp U, Burck-Lehmann U, Mohnike K, Thiele H, Zierler H, Brewer C, Wieacker P. Novel and Recurrent Mutations in Patients with Androgen Insensitivity Syndromes. Horm Res Paediatr 2005; 63:263-9. [PMID: 15925895 DOI: 10.1159/000086018] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Accepted: 03/22/2005] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND/AIMS Androgen insensitivity syndrome (AIS) caused by mutations within the androgen receptor gene represents a variety of phenotypes from females with 46,XY karyotype over individuals with ambiguous genitalia to infertile males. METHODS We studied 24 patients with AIS by sequencing androgen receptor gene. 19 of the investigated patients were affected by complete androgen insensitivity syndrome (CAIS) and 5 suffered from partial androgen insensitivity syndrome (PAIS). RESULTS So far we have detected 12 unreported mutations as well as 9 recurrent mutations (3 recurrent mutations were detected twice) in exons 2-8 of the androgen receptor gene. Three of the novel mutations cause a frameshift with subsequent premature termination and were found in patients with CAIS. These frameshifts were induced by single nucleotide deletion or insertion, or in one case by a 13-bp deletion, respectively. Another premature stop codon found in a CAIS patient results from an already reported nucleotide substitution in exon 5. Furthermore, in a CAIS patient we found a novel duplication of codon 788. All other mutations caused single base substitutions spread through exons 2-8 and were associated with CAIS or PAIS. CONCLUSIONS We report a broad spectrum of different mutations within the AR gene leading to various manifestations of AIS. Apart from truncating mutations, a reliable genotype/phenotype correlation cannot be established. Therefore, modifying factors must be effective.
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Affiliation(s)
- Susanne Ledig
- Institut für Humangenetik der Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
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