Androgen Receptor Gene In Patients Research Articles

Clinical, Biochemical, and Molecular Characterization of Indian Children with Clinically Suspected Androgen Insensitivity Syndrome

This study describes the clinical, biochemical, and molecular characteristics of Indian children with 46,XY DSD and suspected androgen insensitivity syndrome (AIS). Fifty children (median age 3.0 years, range 0–16.5 years) with 46,XY DSD and a suspected diagnosis of AIS were enrolled. Sanger sequencing was performed to identify pathogenic variants in the androgen receptor (AR) gene and to study genotype-phenotype correlations. All 5 (100%) patients with CAIS and 14/45 (31%) patients with PAIS had pathogenic/likely pathogenic variants in the AR gene (overall, 14 different variants in 19 patients; 38.8%). There was no significant difference in clinical (cryptorchidism, hypospadias, or external masculinizing score) or biochemical parameters (gonadotropins and testosterone) between patients with or without pathogenic variants. However, patients with AIS were more likely to have a positive family history, be assigned female gender at birth, and present with gynaecomastia at puberty. Three novel pathogenic/likely pathogenic variants, including one splice donor site variant c.2318+1G>A, one frameshift variant p.H790Lfs*40, and one missense variant p.G821E, were identified in 3 patients with CAIS. The missense variant p.G821E was predicted as deleterious, damaging, disease-causing, and likely functionally inactive by in silico analysis and protein modelling study. Two previously not reported pathogenic/likely pathogenic variants, including p.R386H and p.G396R, were identified in patients with PAIS. This study contributes in expanding the spectrum of pathogenic variants in the AR gene in patients with AIS. Only 31% patients with a provisional diagnosis of PAIS had pathogenic variants in the AR gene, suggesting other possible mechanisms or candidate genes may be responsible for such a phenotypic presentation.

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

BackgroundAndrogens 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 MethodsIn 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.ResultsThe 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.

G1733A (RS6152) polymorphism of the androgen receptor gene in patients with prostate cancer

Aim: The causes of prostate cancer development and molecular mechanism underlying its development and progression are not clearly understood. The aim of this study is to determine the frequency of G1733A (rs6152) polymorphism of the androgen receptor (AR) gene among patients with prostate cancer, and to examine the role of this polymorphism in the development of prostate cancer. Method: DNA samples isolated from 96 individuals (49 patients with prostate cancer and 47 controls) were analyzed with real time-polymerase chain reaction (real time-PCR) in order to determine G1733A (rs6152) polymorphism genotypes and allele frequencies in the AR gene. The results were evaluated statistically. Results: Genotype frequency was determined as 91% GG and 9% AG among the controls, and 67% GG and 33% AG among the patients. G allele frequency was 95% in controls and 83% in patients, whereas A allele frequency was 5% in controls and 17% in patients. There was a statistically significant difference between patient and control groups regarding genotype frequency (p<0.05). Conclusion: Based on the results of our study, we can infer that G1733A (rs6152) polymorphism of the AR gene plays a role in development of prostate cancer in the Turkish population.

Polymorphic CAG Repeat and Protein Expression of Androgen Receptor Gene in Colorectal Cancer.

Although somatic alterations in CAG repeats in the androgen receptor (AR) gene have been suggested to predispose to colorectal cancer, less is known about AR in colorectal cancer carcinogenesis. Because of lack of relevant analysis on CAG repeat length and AR expression in colorectal cancer, we aimed to investigate the prognostic value of polymorphic CAG and protein expression of the AR gene in patients with colorectal cancer. A case-control study was carried out on 550 patients with colorectal cancer and 540 healthy controls to investigate whether polymorphic CAG within the AR gene is linked to increased risk for colorectal cancer. Polymorphic CAG and AR expression were analyzed to clarify their relationship with clinicopathologic and prognostic factors in patients with colorectal cancer. The study showed that the AR gene in patients with colorectal cancer had a longer CAG repeat sequence than those in the control group, as well as increased risk for colorectal cancer among females (P = 0.013), males (P = 0.002), and total colorectal cancer population (P < 0.001), respectively. AR expression exhibited a significant difference in long CAG repeat sequence among males (P < 0.001), females (P < 0.001), and total colorectal cancer study population (P < 0.001). Both long CAG repeat sequence and negative AR expression were associated with a short 5-year overall survival (OS) rate in colorectal cancer. Long CAG repeat sequences and the absence of AR expression were closely related to the development of colorectal cancer. Both long CAG and decreased AR expression were correlated with the poor 5-year OS in patients with colorectal cancer.

Low yield in screening patients with sporadic motor neuron disease for Kennedy disease

The diagnostic yield of testing for Kennedy disease in patients diagnosed with sporadic motor neuron disease (MND) is unclear. We measured the CAG repeat lengths in the androgen receptor gene of patients with progressive limb weakness who had either upper and lower motor signs (n = 130), or lower motor neuron signs alone (n = 30). Only one patient with a long history of lower motor weakness had a repeat length in the Kennedy disease range. Testing for Kennedy disease is unlikely to benefit MND patients with upper motor neuron signs or those with a short history of lower motor signs.

Mutation scanning of the androgen receptor gene in patients with psychiatric disorders reveals highly conserved variants in alcoholic and phobia patients.

Sex steroids exert potent effects on mood and mental state in humans. They may contribute to the risk of psychiatric disorders. To investigate this hypothesis, coding and splice junction sequences of the androgen receptor gene were scanned in genomic DNA samples to search for variants affecting protein structure and expression (VAPSEs). Ninety-six schizophrenics, along with pilot samples of patients with bipolar disorder, attention-deficit hyperactivity disorder, alcoholism and autism were analyzed with DOVAM-S, a robotically enhanced, optimized form of single-strand conformation polymorphism analysis. A total of 669 kb of genomic sequence was analyzed. Two VAPSEs were identified: R726L was found in one of 17 scanned alcoholics, and P516S, a novel VAPSE, was identified in one of three phobia patients. There were no length trends of the CAG triplets associated with schizophrenia. R726L and P516S occur at highly conserved amino acids. Further study is required to assess whether these VAPSEs contribute to the risk of alcoholism or phobia or other diseases.

Analysis of the polymorphic CAG repeat length in the androgen receptor gene in patients with testicular germ cell cancer.

Changes in the length of a polymorphic trinucleotide (CAG) repeat in the androgen receptor (AR) gene, which may lead to altered transactivation of the AR gene, have been implicated to play a role in the pathogenesis of several forms of endocrine cancer and certain reproductive disorders. Subjects with reproductive disorders that are associated with a relative deficiency of androgen function carry an increased risk for testicular cancer, therefore we have examined the (CAG)n in the AR gene in DNA isolated from peripheral blood cells of 102 patients diagnosed with testicular germ cell neoplasia and compared them with a control group of 110 healthy men with proven fertility. All patients and control subjects underwent comprehensive andrological examination that included reproductive hormone profiles and the analysis of the (CAG)n in the AR gene that was done by means of PCR and DNA sequencing. There was no difference in the distribution of (CAG)n between the subjects and controls, no association of (CAG)n and the tumor type and no association with severity of the disease. We conclude that the high risk of testicular germ cell cancer in the Danish population is not associated with the (CAG)n polymorphism in the AR gene.

Screening for mutations of the androgen receptor gene in patients with isolated cryptorchidism

Objective: To evaluate the occurrence of mutations of androgen receptor (AR) gene in patients with isolated cryptorchidism.Design: Controlled clinical study.Setting: Yamagata University Hospital, Yamagata and Tokyo Electric Power Company Hospital, Tokyo, Japan.Patient(s): Patients with isolated cryptorchidism (n = 48) and a control group of men with normal phenotype (n = 20).Intervention(s): Blood (lymphocyte DNA).Main Outcome Measure(s): Screening of the AR gene in exons 1–8 using single-strand conformational polymorphism analysis.Result(s): No abnormal band patterns were detected in patients with cryptorchidism or in control subjects within the eight exons of the AR gene.Conclusion(s): AR gene alterations appear to be an unlikely cause of isolated cryptorchidism.

Eight novel mutations of the androgen receptor gene in patients with androgen insensitivity syndrome.

Androgen insensitivity syndrome (AIS) is an X-linked genetic disorder of male sexual differentiation caused by mutations in the androgen receptor (AR) gene. A reliable genotype-phenotype correlation in these patients does not exist as yet. Here we report the molecular studies performed on eight individuals with AIS. Exon-specific polymerase chain reaction (PCR), single-strand conformation polymorphism, and sequencing analyses, were performed in exons 2 to 8 of the AR gene. In one case, total cellular RNA was extracted from genital skin fibroblasts and reverse transcriptase-PCR was performed. Six different point mutations leading to amino acid substitutions (P682T, Q711E, G743E, F827V, H874R, D879Y), one splice-junction mutation (g-->c at +5, exon 6/intron 6), and a missense mutation without amino acid substitution (S888S) were identified. All mutations, including a de novo mutation, were previously undescribed on the steroid binding domain. Of the eight mutations identified, four led to a complete female phenotype (codons 743, 827, 874 and the donor splice site +5), two were detected in phenotypic females with partial virilization (codons 682 and 711), and two were present in phenotypic male subjects with undervirilized external genitalia, thus indicating that all of these sites determine AR functional activity.

Polymorphisms in the Vitamin D Receptor Gene and the Androgen Receptor Gene and the Risk of Benign Prostatic Hyperplasia

Objective: Little is known about risk factors for the development of benign prostatic hyperplasia (BPH). Recently, associations were observed between prostate cancer (CaP) risk and polymorphisms in the vitamin D receptor (VDR) gene and the androgen receptor (AR) gene. Since both receptors are relevant for prostate growth, the VDR and AR are also expected to be involved in the development of BPH. The objective of this study is to establish the relationship between the risk of BPH and a polymorphism in the number of CAG repeats in the AR gene and a TaqI restriction enzyme polymorphism in the VDR gene.Methods: For this study, 98 patients who had been treated for BPH–related complaints and 61 convenience controls (predominantly bladder cancer patients) were recruited from the outpatient clinic. DNA was isolated from peripheral blood, and genotyping was performed with PCR–based methods. Means as well as odds ratios (ORs) with 95% confidence intervals (CI) were calculated using SPSS software.Results: The mean number of CAG repeats in the AR gene in patients and controls was found to be similar: 21.8 (SD = 2.8) and 21.9 (SD = 2.9), respectively. In the subgroup of patients with a prostate volume of at least 50 cm³, the mean number of repeats was 21.5 (SD = 2.6). The OR for BPH for individuals with homozygous presence of the VDR TaqI restriction fragment length polymorphism (RFLP) (tt) versus individuals with homozygous absence (TT) or heterozygotes (Tt) was found to be 1.0 (95% CI 0.4–2.4). For individuals with a prostate volume of at least 50 cm³, the OR was 1.2 (95% CI 0.5–3.2).Conclusion: Unlike earlier observations in prostate cancer, we did not find an association between the CAG repeat polymorphism in the AR gene and the TaqI RFLP polymorphism in the VDR gene and the risk of BPH.

Molecular Analysis of the Androgen Receptor Gene in Patients with Complete and Partial Androgen Insensibility Syndrome

Molecular Analysis of the Androgen Receptor Gene in Patients with Complete and Partial Androgen Insensibility Syndrome

Functional characterisation of mutations in the ligand-binding domain of the androgen receptor gene in patients with androgen insensitivity syndrome.

Five mutations in the ligand-binding domain of the androgen receptor gene were identified in patients with complete (A765T, C784Y, R831X and M895T) or partial (R840G) androgen insensitivity. A765T and R831X have been reported previously whereas the other three mutations are novel. Receptors carrying these mutations were transiently expressed in COS-1 cells, and androgen binding and capacity to transactivate an androgen-responsive reporter gene were assayed. C784Y led to abolished androgen binding and transactivating capacity, R840G and M895T showed reduced specific binding and partial transactivation. The in vitro functions of the R840G and M895T mutants were improved with supraphysiological concentrations of steroid.

Mutations of the androgen receptor gene in patients with complete androgen insensitivity.

Mutations of the androgen receptor gene in patients with complete androgen insensitivity.

Mutations of the androgen receptor gene in patients with complete androgen insensitivity

Mutations of the androgen receptor gene in patients with complete androgen insensitivity

Molecular basis of androgen insensitivity.

Mutations in the androgen receptor gene in 46,XY individuals can be associated with the androgen insensitivity syndrome, of which the phenotype can vary from a female phenotype to an undervirilized or infertile male phenotype. We have studied the androgen receptor gene of androgen insensitivity patients to get information about amino acid residues or regions involved in DNA binding and transcription activation. Genomic DNA was analysed by PCR-SSCP under two different conditions. Three new mutations were found in exon 1 of three patients with a female phenotype. A cytosine insertion at codon 42 resulted in a frameshift and consequently in the introduction of a premature stop at codon 171. Deletion of an adenine at codon 263 gave rise to a premature stop at codon 292. In both these cases, receptor protein was not detectable and hormone binding was not measurable. In a third patient, a guanine-to-adenine transition at codon 493 converted a tryptophan codon into a stop codon. Genital skin fibroblasts from this patient were not available. In exon 2 of the androgen receptor gene of a patient with receptor-positive androgen insensitivity, a cytosine-to-adenine transition, converting alanine 564 into an aspartic acid residue, resulted in defective DNA binding and transactivation. In three other receptor-positive androgen insensitivity patients no mutations were found with PCR-SSCP.

Characterization of two point mutations in the androgen receptor gene of patients with perineoscrotal hypospadia

Perineoscrotal hypospadia is a major sign of sexual ambiguity due to inadequate androgen action in genetic and gonadal males. In patients showing these symptoms we have detected two androgen receptor gene mutations. In consequence we characterized the properties of the mutant receptors with respect to hormone-binding, transactivation and DNA-binding. An amino acid substitution alanine-596→threonine in the D-box of the androgen receptor was detected in 3 and 2 brothers, respectively. This mutant receptor, AR-thr 596, bound ligand in a normal fashion. It showed a promoter-dependent defect of transactivation and was unable to induce transcription of a promoter containing one androgen responsive element but showed almost wild-type transactivation of a promoter containing two closely spaced androgen-responsive elements. The complex promoter of the human prostate-specific antigen gene was induced with intermediate efficiency. In electrophoretic mobility shift assays AR-thr 596 was unable to form a complex with oligonucleotides containing 1 or 2 androgen responsive elements, however its DNA-binding activity was restored by an anti-androgen receptor antibody in the presence of ligand. A point mutation which caused substitution of serine-703 in the hormone-binding domain with glycine was detected in a new-born male with ambiguous genitalia. This mutant receptor, AR-gly 703, showed a reduced ligand affinity. The total amount of specific androgen binding sites in genital fibroblasts of the patient was reduced. Transactivation activity of AR-gly 703 was dependent on hormone concentration. It was inactive at low levels of androgens but was fully activated in the presence of high androgen concentrations. The nature of the promoter had no effect on transactivation properties of this mutant androgen receptor. Its DNA-binding activity in gel shift experiments was normal.

Complete androgen insensitivity syndrome associated with a de novo mutation of the androgen receptor gene detected by single strand conformation polymorphism

In a French child with complete androgen insensitivity syndrome and negative receptor-binding, no gross deletion has been found. Using single-strand conformation polymorphism assay, a useful screening method for rapid detection of DNA sequence alterations, and direct DNA sequencing, a G-T nucleotide substitution in exon 5 of the androgen receptor gene at nucleotide 2590 was found. This changed codon 743, glycine to valine, in the hormone-binding domain and created a new recognition sequence for the restriction endonuclease Asp HI. Amplification of exon 5 by polymerase chain reaction followed by digestion with Asp HI enabled easy recognition of the described mutation. Since the mother's exon 5 was undigested, we suspected the de novo nature of this nucleotide substitution. This was confirmed by direct sequencing of the mother's DNA which only showed the canonical sequence. To our knowledge, there has been no previous report of a de novo mutation described within the androgen receptor gene in patients with androgen insensitivity syndrome.

Triplet Repeat Mutations: Amplification Within Pedigrees Generates Three Human Diseases

AN UNSTABLE DNA sequence, made up of three contiguously repeating nucleotides, has been pinpointed recently as the genetic cause of fragile X syndrome, myotonic dystrophy, and Kennedy disease. This novel mutation provides a specific molecular mechanism behind the phenomenon of anticipation— the clinical observation that some genetic diseases manifest at either an earlier age or more severely in successive generations. (Please refer to accompanying article.) The consequences of this unstable sequence vary widely, depending on the gene in which it occurs and its location within the gene. So too does the number of repeats that lead to normal, mildly, and severely affected outcomes. The following summarizes more than a dozen presentations on this topic at the recent annual meeting of the American Society of Human Genetics. <h3>Kennedy Disease</h3> In early 1991, researchers identified an expansion of the CAG trinucleotide repeat sequence in the androgen receptor gene of patients with X-linked

A unique point mutation in the androgen receptor gene in a family with complete androgen insensitivity syndrome

To further delineate the diversity of genetic alterations in the gene coding for the androgen receptor in individuals with the androgen insensitivity syndrome and to increase our understanding of the disease at the molecular level. This was a prospective study in which genomic deoxyribonucleic acid (DNA) from individuals with androgen insensitivity were examined through the polymerase chain reaction and DNA sequencing analysis. Eleven complete and four individuals with partial androgen insensitivity syndrome were examined. Exons two through eight were grossly intact in all study subjects. Nucleotide sequence analysis revealed that three of three related family members with complete androgen insensitivity had the same guanine to adenine base substitution in exon five of the steroid-binding domain. The subsequent alanine to threonine amino acid conversion may have resulted in a configurational change of the androgen receptor protein leading to complete androgen insensitivity. This precise alteration has not been previously identified in the human androgen receptor gene in patients with the androgen insensitivity syndrome.

Probing genomic deoxyribonucleic acid for gene rearrangement in 14 patients with androgen insensitivity syndrome

Androgen insensitivity appears to involve mutations in the X-linked androgen receptor (AR) gene in genetic males. In this study; 14 patients with androgen insensitivity syndrome (unrelated patients [n = 6]; related patients [n = 8]) were studied. Ten patients had complete and 4 had partial insensitivity to androgens. Deoxyribonucleic acid samples from controls and study subjects were examined with probes specific for the AR gene domains (hAR1, hAR2, hAR3). In one subject with complete androgen insensitivity syndrome, a reduction in size of the 2.4 kilobase band hybridizing to hAR1 was noted. Southern blot analysis of these subjects, however, did not detect deletions or gene rearrangement. These results suggest that deletions detectable by Southern method are infrequent mutants of the AR gene in patients with androgen insensitivity syndrome.