Androgen Receptor Polymorphisms (CAG Repeat Lengths) in Androgenetic Alopecia, Hirsutism, and Acne

1998 ◽  
Vol 3 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Marty E. Sawaya ◽  
Alan R. Shalita
Keyword(s):  
Androgen Receptor ◽  
Hair Follicles ◽  
Trinucleotide Repeats ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Androgenetic Alopecia ◽  
Skin Disorders ◽  
Men And Women ◽  
Amino Terminal

Background: The androgen receptor (AR) is a structurally conserved member of the nuclear receptor superfamily. The amino-terminal domain is required for transcriptional activation and contains a region of polyglutamine encoded by CAG trinucleotide repeats. In humans, the number of CAG repeats is polymorphic. Expansion of CAG repeats in the AR has clinical implications for human disease. Objective: Androgens influence androgenetic alopecia (AGA), hirsutism, and acne; the polymorphisms in CAG repeat length may affect the clinical course of patients with these cutaneous disorders. The purpose of this study is to test for an association between these disorders and CAG repeat length. Methods: We analyzed normal lymphocyte genomic DNA from a total of 48 men and 60 women. The CAG repeat region of the AR was amplified by polymerase drain reaction (PCR) and the products were sized on polyacrylamide gels. Results: In normal men and women controls, a range of 12 to 29 trinucleotide repeats was found, with men having 22 ± 4 (M ± SD), women 21 ± 3. Men with AGA had 19 ± 3, whereas women with AGA had 17 ± 3. Men with acne had 21 ± 3, whereas women had 20 ± 3; men with AGA and acne had 18 ± 4; and women with hirsutism had 16 ± 3. Women with a combination of at least two disorders also had 16 ± 3 trinucleotide repeats. Conclusion: Shorter CAG-repeat lengths may be associated with the development of androgen-mediated skin disorders in men and women. These data suggest that CAG-repeat length in AR may affect androgen mediated gene expression in hair follicles and sebaceous glands in men and women with these androgenic skin disorders.

scholarly journals Cag Repeat Number in the Androgen Receptor Gene and Prostate Cancer

2012 ◽  
Vol 15 (1) ◽  
pp. 31-36 ◽  
Author(s):  
S Madjunkova ◽  
A Eftimov ◽  
V Georgiev ◽  
D Petrovski ◽  
A Dimovski ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Risk ◽  
Receptor Gene ◽  
Prostate Cancer Risk ◽  
Androgen Receptor Gene ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Repeat Number

Cag Repeat Number in the Androgen Receptor Gene and Prostate CancerProstate cancer (PC) is the second leading cause of cancer deaths in men. The effects of androgens on prostatic tissue are mediated by the androgen receptor (AR) gene. The 5' end of exon 1 of the AR gene includes a polymorphic CAG triplet repeat that numbers between 10 to 36 in the normal population. The length of the CAG repeats is inversely related to the transactivation function of the AR gene. There is controversy over association between short CAG repeat numbers in the AR gene and PC. This retrospective case-control study evaluates the possible effect of short CAG repeats on the AR gene in prostate cancer risk in Macedonian males. A total of 392 male subjects, 134 PC patients, 106 patients with benign prostatic hyperplasia (BPH) and 152 males from the general Macedonian population were enrolled in this study. The CAG repeat length was determined by fluorescent polymerase chain reaction (PCR) amplification of exon1 of the AR gene followed by capillary electrophoresis (CE) on a genetic analyzer. The mean repeat length in PC patients was 21.5 ±2.65, in controls 22.28 ±2.86 (p = 0.009) and in BPH patients 22.1 ±2.52 (p = 0.038). Short CAG repeats (<19) were found in 21.64% of PC patients vs. 9.43% in BPH patients (p = 0.0154). We also found an association of low Gleason score (<7) with short CAG repeat (<19) in PC patients (p = 0.0306), and no association between the age at diagnosis of PC and BPH and CAG repeat length. These results suggest that reduced CAG repeat length may be associated with increased prostate cancer risk in Macedonian men.

scholarly journals CAG repeat polymorphism in androgen receptor and infertility: A case-control study

2021 ◽  
pp. 845-850
Author(s):  
Shiva Sharestani ◽  
Seyed Mehdi Kalantar ◽  
Nasrin Ghasemi ◽  
Ehsan Farashahi Yazd
Keyword(s):  
Androgen Receptor ◽  
Case Control Study ◽  
Case Control ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Control Group ◽  
Case Group ◽  
The Difference ◽  
Control Study

Background: Androgens play a role in the development of male phenotype and spermatogenesis during puberty, the function of which is regulated by the androgen receptor (AR) gene. There is a polymorphism site in exon 1 of the gene encoding this receptor that can have different frequencies of CAG trinucleotide repeats and leads to the formation of polyglutamine chains of different lengths in the N-terminal domain of the AR protein and reduced sperm production by affecting spermatogenesis. Objective: To investigate whether the cause of a group of unexplained infertilities could be the increased frequency of CAG repeats in the AR gene of patients with oligozoospermia and azoospermia. Materials and Methods: In this case-control study, 84 men including 42 with unexplained infertility As a case group and 42 fertile men as a control group were selected. The frequency of CAG repeats was determined by the polymerase chain reaction method and then the difference in the frequency of these repeats was determined based on the difference in band size on the agarose gel. Results: The mean CAG repeat length in the azoospermia and oligozoospermia group was 17.5 ± 0.63 and in the fertile group it was 16.11 ± 0.75 (p = 0.46). In addition, most men (88.1% in the case group and 71.41% in the control group) had 13-23 repeats. Conclusion: No significant correlation was found between CAG repeat length and the risk of male factor infertility in an ethnically defined population of Iranian men. The role of regulatory factors and epigenetic changes should be taken into account too. Key words: Infertility, Azoospermia, Androgens, X chromosome, Spermatogenesis.

Role of the CAG Repeat Polymorphism of the Androgen Receptor Gene in Polycystic Ovary Syndrome (PCOS)

2011 ◽  
Vol 120 (02) ◽  
pp. 73-79 ◽  
Author(s):  
A. Schüring ◽  
A. Welp ◽  
J. Gromoll ◽  
M. Zitzmann ◽  
B. Sonntag ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Polycystic Ovary Syndrome ◽  
Polycystic Ovary ◽  
Receptor Gene ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Repeat Polymorphism ◽  
Ovary Syndrome

AbstractPolycystic ovary syndrome (PCOS) is a frequent heterogenic disorder with a familial background. Androgenic effects, determining the clinical features of the syndrome, are mediated by the androgen receptor (AR), whose activity is modulated by a genetic polymorphism. We investigated the role of the CAG repeat polymorphism of the androgen receptor in PCOS.In the infertility unit of a university clinic, 72 PCOS patients were compared with 179 ovulatory controls undergoing a standardized diagnostic work-up. The number of CAG repeats was determined by PCR, labelling with IR-800 and PAGE. X-chromosome inactivation was assessed by a methylation-sensitive assay.Compared to controls, PCOS patients displayed a shorter mean CAG repeat length, encoding for higher AR activity (P=0.001). CAG repeat length correlated inversely with oligomenorrhea, a central androgen dependent feature of the syndrome (P=0.005). In a binomial regression analysis including BMI, LH and free testosterone, CAG repeat length was identified as an independent risk factor for PCOS (P=0.002).The CAG repeat polymorphism could constitute one of the genetic factors modulating the syndrome’s phenotype, contributing to its clinical heterogeneity and associated metabolic consequences.

scholarly journals Identification of Differentially Expressed Genes in Prostatic Epithelium in Relation to Androgen Receptor CAG Repeat Length

2006 ◽  
Vol 21 (2) ◽  
pp. 96-105 ◽  
Author(s):  
C.M. Coutinho-Camillo ◽  
E.C. Miracca ◽  
M.L. Dos Santos ◽  
S. Salaorni ◽  
A.S. Sarkis ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Differentially Expressed Genes ◽  
Repeat Length ◽  
Cag Repeat ◽  
Differentially Expressed ◽  
Cag Repeats ◽  
Pcr Analysis ◽  
Length Variation ◽  
Rt Pcr

The CAG repeat within exon 1 of the androgen receptor (AR) has been associated with the development of prostate cancer. The shorter number of glutamine residues in the protein has been associated with a higher transcriptional activity of the AR and increased relative risk for prostate cancer. In an attempt to identify differentially expressed genes in prostate cancer in relation to AR CAG repeat length variation, in this study we used total mRNA from normal and tumor tissues from 2 prostate cancer patients with AR alleles containing 19 and 26 CAG repeats to perform differential-display RT-PCR analysis. We were able to identify 48 different transcripts that showed homology to several known genes associated with different biological pathways. Among the differentially expressed genes, ATRX and SFRP1 were further validated by quantitative RT-PCR. The transcripts of both ATRX and SFRP1 genes proved to be down-regulated in most of the prostate tumors analyzed by quantitative RT-PCR. Hypermethylation of the promoter region of the SFRP1 gene was found in 17.5% (7/40) of the cases analyzed and was associated with the loss of SFRP1 expression (p=0.014). The differentially expressed genes identified in this study are implicated in several cellular pathways that, when up- or down-regulated, might play a role in the tumorigenic process of the prostate.

scholarly journals Evidence that the CAG repeat in the androgen receptor gene is associated with the age-related decline in serum androgen levels in men

1999 ◽  
Vol 162 (1) ◽  
pp. 137-142 ◽  
Author(s):  
K Krithivas ◽  
SM Yurgalevitch ◽  
BA Mohr ◽  
CJ Wilcox ◽  
SJ Batter ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Sex Hormone Binding Globulin ◽  
Sample Survey ◽  
Hormone Levels ◽  
Age Related ◽  
Androgen Levels

In men over 30 years old, serum levels of testosterone (T) decrease with age. A shorter polymorphic CAG repeat length in exon 1 of the androgen receptor (AR) gene is associated with higher transcription activation by the AR. We determined the number of CAG repeats for 882 men aged between 40 and 70 years from the Massachusetts Male Aging Study (MMAS). MMAS is a population-based random sample survey of men for whom baseline (1987-1989, mean age 53+/-8 years) and follow-up (1995-1997, mean age 61+/-8 years) serum hormone levels were available. Multiple linear regression was used to determine if CAG repeat length would be predictive of hormone levels at follow-up. Hormone levels measured included T, free T, albumin-bound T, dihydrotestosterone (DHT), sex hormone-binding globulin (SHBG) and luteinizing hormone (LH). The CAG repeat length was significantly associated with T (P=0.041), albumin-bound T (P=0.025) and free T (P=0.003) when controlled for age, baseline hormone levels and anthropometrics. Follow-up levels of T decreased by 0.74%+/-0.36 per CAG repeat decrement. Likewise, the percentages of free and albumin-bound T decreased by 0.93%+/-0.31 and 0.71%+/-0.32 per CAG repeat decrement respectively. These results suggest that androgen levels may be modulated by AR genotype.

Genetic Screening in Infertile Mexican Men: Chromosomal Abnormalities, Y Chromosome Deletions, and Androgen Receptor CAG Repeat Length

2008 ◽  
Vol 29 (6) ◽  
pp. 654-660 ◽  
Author(s):  
S. G. Martinez-Garza ◽  
M. C. Gallegos-Rivas ◽  
M. Vargas-Maciel ◽  
J. M. Rubio-Rubio ◽  
M. E. de los Monteros-Rodriguez ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Y Chromosome ◽  
Genetic Screening ◽  
Chromosomal Abnormalities ◽  
Repeat Length ◽  
Cag Repeat ◽  
Chromosome Deletions ◽  
Mexican Men

Androgen Receptor CAG Repeat Length in Relation to Phenotype Among Females with Nonclassical 21-Hydroxylase Deficiency

2014 ◽  
Vol 47 (07) ◽  
pp. 491-496
Author(s):  
S. Ben-Shachar ◽  
I. Ayalon ◽  
H. Reznik-Wolf ◽  
Y. Tenenbaum-Rakover ◽  
N. Zuckerman-Levin ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Repeat Length ◽  
Cag Repeat ◽  
Hydroxylase Deficiency ◽  
21 Hydroxylase Deficiency

scholarly journals Incidence of Huntington disease in a northeastern Spanish region: a 13-year retrospective study at tertiary care centre

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Paula Sienes Bailo ◽  
Raquel Lahoz ◽  
Juan Pelegrín Sánchez Marín ◽  
Silvia Izquierdo Álvarez
Keyword(s):  
Retrospective Study ◽  
Huntington Disease ◽  
Tertiary Care ◽  
Genetic Diagnosis ◽  
Repeat Length ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Incomplete Penetrance ◽  
Predictive Test ◽  
Incident Cases

Abstract Background Despite the progress in the knowledge of Huntington disease (HD) in recent years, the epidemiology continues uncertain, so the study of incidence becomes relevant. This is important since various factors (type of population, diagnostic criteria, disease-modifying factors, etc.) make these data highly variable. Therefore, the genetic diagnosis of these patients is important, since it unequivocally allows the detection of new cases. Methods Descriptive retrospective study with 179 individuals. Incidence of HD was calculated from the ratio of number of symptomatic cases newly diagnosed per 100,000 inhabitants per year during the period 2007–2019 in Aragon (Spain). Results 50 (27.9%) incident cases of HD (CAG repeat length ≥ 36) were identified from a total of 179 persons studied. The remaining 129/179 (72.1%) were HD negative (CAG repeat length < 36). 29 (58.0%) females and 21 (42.0%) males were confirmed as HD cases. The overall incidence was 0.648 per 100,000 patient-years. 11/50 positive HD cases (22.0%) were identified by performing a predictive test, without clinical symptoms. The minimum number of CAG repeats found was 9 and the most common CAG length among HD negative individuals was 16. Conclusions Our incidence lied within the range reported for other Caucasian populations. Implementation of new techniques has allowed to determine the exact number of CAG repeats, which is especially important in patients with triplet expansions in an HD intermediate and/or incomplete penetrance allele, both in diagnostic, predictive and prenatal tests.

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