Androgen receptor post-translational modifications and their implications for pathology.

A major mechanism to modulate the biological activities of the androgen receptor (AR) involves a growing number of post-translational modifications (PTMs). In this review we summarise the current knowledge on the structural and functional impact of PTMs that affect this major transcription factor. Next, we discuss the cross-talk between these different PTMs and the presence of clusters of modified residues in the AR protein. Finally, we discuss the implications of these covalent modifications for the aetiology of diseases such as spinal and bulbar muscular atrophy (Kennedy's disease) and prostate cancer, and the perspectives for pharmacological intervention.

Detection of Molecular Variations at Androgen Receptor Gene in 46,XY Differences in Sex Development Cases.

Introduction: One of the common causes of 46,XY differences in sex development (DSD) cases is androgen insensitivity syndrome. This X-linked recessive inherited condition is associated with pathological variations of the AR gene, leading to defects in androgen action. Affected 46,XY infants or individuals experience variable degrees of undervirilization and those with severe form will have female-like external genitalia. Therefore, they were more likely assigned and reared as females. The confirmatory molecular test is often needed due to similar clinical manifestations with other conditions causing 46,XY DSD. Since in our country, the molecular test for the AR gene is lacking, the study is conducted as a preliminary study to elaborate on the possibility of developing a molecular test for the AR gene in 46,XY DSD cases. Methods: Archived DNAs of 13 46,XY DSD cases were analyzed using polymerase chain reaction and direct sequencing for molecular defects in the AR gene. Clinical and hormonal data were collected and analyzed. Results: The study successfully amplified and visualized the eight exons of the AR gene and revealed two subjects carrying AR gene variants at exon 7. In the first case, 1.2-year-old boy carried heterozygous p.Gln825Arg, which has never been reported elsewhere, and the second subject, a 2.1-year-old girl with heterozygous p.Arg841His. Both subjects presented with severe undervirilization of external genitalia with external genitalia masculinization scores (EMS) of 1.5 and 3. Conclusion: In this series, two of 13 46,XY DSD cases carried variants at the AR gene, resulting in complete androgen insensitivity syndrome.

Complete androgen insensitivity syndrome coexisting with müllerian duct remnants: a case report and literature review.

This study represents the first documentation of the coexistence of complete androgen insensitivity syndrome (CAIS) with Müllerian duct remnants (MDRs) in mainland China. Additionally, we provide a comprehensive review of the existing literature concerning CAIS with MDRs resulting from androgen receptor (AR) gene mutations. This study broadens the clinical spectrum of CAIS and offer novel insights for further exploration into Müllerian duct regression. A 14-year-old patient, initially raised as female, presented to the clinic with complaints of "primary amenorrhea." Physical examination revealed the following: armpit hair (Tanner stage 2), breast development (Tanner stage 4 with bilateral breast nodule diameter of 7 cm), sparse pubic hair (Tanner stage 3), clitoris measuring 0.8 cm × 0.4 cm, separate urethral and vaginal openings, and absence of palpable masses in the bilateral groin or labia majora. The external genital virilization score was 0 points. Serum follicle-stimulating hormone level was 13.43 IU/L, serum luteinizing hormone level was 31.24 IU/L, and serum testosterone level was 14.95 nmol/L. Pelvic magnetic resonance imaging (MRI) did not reveal a uterus or bilateral fallopian tubes, but nodules on both sides of the pelvic wall indicated cryptorchidism. The karyotype was 46,XY. Genetic testing identified a maternal-derived hemizygous variation c.2359C > T (p.Arg787*) in the AR gene. During abdominal exploration, dysplastic testicles and a dysplastic uterus were discovered. Histopathological analysis revealed the presence of fallopian tube-like structures adjacent to the testicles. The CAIS patient documented in this study exhibited concurrent MDRs, thus expanding the spectrum of clinical manifestations of AIS. A review of prior literature suggests that the incidence of CAIS combined with histologically MDRs is not uncommon. Consequently, the identification of MDRs in AIS cases may represent an integral aspect of clinical diagnosis for this condition.

Analysis of genetic and clinical characteristics of androgen insensitivity syndrome: a cohort study including 12 families.

CONTEXT: Androgen insensitivity syndrome (AIS) manifests itself as variable symptoms of under-virilization in patients with 46, XY disorders caused by androgen receptor (AR) gene variants. This large-sample study aimed to correlate the genotypes and phenotypes to the fertility of individuals. METHODS: This was a cohort study that analyzed genetic and clinical characteristics of patients with AIS from a single center in China. RESULTS: The 117 patients were divided into 53 with complete AIS (CAIS) and 64 with partial AIS (PAIS). At their first visit the median age was 1.83 years (0.92-4.17) and the EMS was 3.0 (2.0-6.0). At the last follow-up, 92% (49/53) of patients with CAIS maintained their female gender, and 94% (60/64) of patients with PAIS were raised as males. No gender anxiety was observed in this study. Eighty-eight AR variants were identified, with 31 (35%) being unreported. Moreover, 24% (21/88) occurred more than once. The variants that appeared most frequently were located at amino acid 841, including p.R841H(n=5) and p.R841C(n=2). Variants p.N706S, p.R856H, and p.A871V were each observed 4 times. In terms of inheritance, 83% of patients with parental verification inherited variants from their mothers. We also observed that the variants from one case were inherited from his maternal grandfather who had hypospadias. CONCLUSION: Most children with PAIS were raised as males. The abundance of maternally inheritable variants and the presence of case of preserved fertility indicate the fertility potential in patients with AIS. Hence, we recommend a careful evaluation of gonadectomy when fertility preservation is being considered.

Hydropathic AF-2 variants in the androgen receptor gene among androgen insensitivity patients.

BACKGROUND: Androgen insensitivity syndrome (AIS) is a common condition among individuals with differences of sexual development (DSD) and results from germline allelic variants in the androgen receptor (AR) gene. Understanding the phenotypic consequences of AR allelic variants that disrupt the activation function 2 (AF2) region is essential to grasping its clinical significance. OBJECTIVES: This study aims to provide insights into the phenotypic characteristics and clinical impact of AR mutations affecting the AF2 region in AIS patients. We achieve this by reviewing reported AR variants in the AF2 region among individuals with AIS, including identifying a new phenotype associated with the c.2138T>C variant (p.Leu713Pro) in the AR gene. MATERIALS AND METHODS: We comprehensively reviewed AR variants within the AF2 region reported in AIS and applied molecular dynamics simulations to assess the impact of the p.Leu713Pro variant on protein dynamics. RESULTS: Our review of reported AR variants in the AF2 region revealed a spectrum of phenotypic outcomes in AIS patients. Molecular dynamics simulations indicated that the p.Leu713Pro variant significantly alters the local dynamics of the AR protein and disrupts the correlation and covariance between variables. DISCUSSION: The diverse phenotypic presentations observed among individuals with AR variants in the AF2 region highlight the complexity of AIS. The altered protein dynamics resulting from the p.Leu713Pro variant further emphasize the importance of the AF2 region in AR function. CONCLUSION: Our study provides valuable insights into AR mutations' phenotypic characteristics and clinical impact on the AF2 region in AIS. Moreover, the disruption of protein dynamics underscores the significance of the AF2 region in AR function and its role in the pathogenesis of AIS.

Clinical, Hormonal, and Genetic Spectrum of 46 XY Disorders of Sexual Development (DSD) Patients.

OBJECTIVES: To evaluate the clinical, hormonal and genetic characteristics of 46XY disorders of sexual development (DSD) patients from South India. METHODS: 46XY DSD patients with a provisional diagnosis of 17ß-hydroxysteroid dehydrogenase 3 (17BHSD3) deficiency, 5 alpha-reductase type 2 deficiency (5ARD2) or partial androgen insensitivity syndrome (PAIS) based on clinical and hormonal analysis were included in this study. All the patients underwent detailed clinical and hormonal evaluations. Targeted next-generation sequencing for all three genes (AR, HSD17B3, and SRD5A2) in parallel was carried out for all the included patients and their parents. RESULTS: Based upon the clinical and hormonal analysis, among the 37 children with 46XY DSD in the present study, 21 children were diagnosed with 5ARD2, 10 with PAIS, and six with 17BHSD3 deficiency. However, genetic analysis revealed pathogenic mutations in nine patients - six in the AR gene, two in the SRD5A2 gene, and one in the HSD17B3 gene. The concordance rate between provisional hormonal and genetic diagnosis was only 22.2%. Two out of six subjects with AR gene variants were positive for somatic mosaicism. CONCLUSIONS: In the present study, a positive genetic diagnosis was detected in nine patients (24%), including five novel variants. In this study, mutations in the AR gene was the most reported. The authors did not find the testosterone: dihydrotestosterone (T: DHT) ratio to be an accurate hormonal diagnostic tool.

Preimplantation Genetic Diagnosis of Androgen Resistance Syndrome Caused by Mutation on the AR Gene in Vietnam.

Background: Androgen resistance syndrome or androgen insensitivity syndrome (AIS - Androgen Insensitivity Syndrome, OMIM 300068) is an X-linked recessive genetic syndrome causing disorders of sexual development in males. This disease is caused by mutations in the AR gene located on the X chromosome, which encodes the protein that structures the androgen receptor, with the role of receiving androgens. Mutation of the AR gene causes complete or partial loss of androgen receptor function, thereby androgen not being obtained and exerting its effect on target organs, resulting in abnormalities of the male reproductive system due to this organ system, differentiating towards feminization under the influence of estrogen. Disease prevention can be achieved by using pre-implantation genetic diagnosis, which enables couples carrying the mutation to have healthy offspring. Aim: To carry out preimplantation genetic diagnosis of androgen resistance syndrome. Methods: Sanger sequencing was used to detect the mutation in the blood samples of the couple, their son, and 01 embryo that were biopsied on the fifth day based on the findings of next-generation sequencing (NGS) of the affected son. We combined Sanger sequencing and linkage analysis using short tandem repeats (STR) to provide diagnostic results. Results: We performed preimplantation genetic diagnosis for AIS on an embryo from a couple who had previously had an affected son. Consequently, one healthy embryo was diagnosed without the variant NM_000044: c.796del (p.Asp266IlefsTer30). Conclusion: We report on a novel variant (NM_000044: c.796del (p.Asp266IlefsTer30)) in the AR gene discovered in Vietnam. The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of AIS but wish to have healthy children.

In Silico Analysis of Functional SNPs in Genes of Complete Androgen Insensitivity Syndrome (CAIS): A Retrospective, Case-Control Study.

Background: Complete androgen insensitivity syndrome (CAIS) is one of the categories of androgen insensitivity syndrome (AIS) described as complete failure of the cell to react to androgens with external genitalia of a normal female. People with AIS condition are genetically male, with XY karyotype in each cell, but their bodies are unable to respond to male sex hormones (called androgens). It is associated with infertility as well as developing cancerous conditions. The genetic association of CAIS involves polymorphism of genes such as NR5A1, SOX9, SRD5A2, CBX2, GATA4, and SRY. Their mutation and participation in genetics of CAIS can be studied by Single Nucleotide polymorphism (SNP) analysis which is a way to detect genetic variations. SNP in coding region leads to synonymous and non-synonymous mutations. Hence, this study highlights analysis of SNPs associated with CAIS. Our aim is to study SNP analysis of NR5A1, SOX9, SRD5A2, CBX2, GATA4, SRY genes in Complete Androgen Insensitivity Syndrome. Methods: SIFT and Polyphen analysis was performed for all the genes and samples were subjected for PCR-SSCP technique. Results: SNPs were analyzed for the genes associated with CAIS. Benign and damaging SNPs were identified. DNA Samples were amplified using PCR technique and they will be analyzed using Single-strand conformation polymorphism (SSCP). Conclusions: As SNPs have decreased stability, damaging and benign character, they can be used as candidate hallmarks in study of Complete Androgen Insensitivity Syndrome.

Magnetic resonance imaging features of complete androgen insensitivity syndrome in comparison to Mayer-Rokitansky-Küster-Hauser syndrome.

PURPOSE: Complete androgen insensitivity syndrome (CAIS) and Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) share common clinical features such as female phenotype, vaginal hypoplasia, and primary amenorrhea. Magnetic resonance imaging (MRI) is performed to investigate the cause of primary amenorrhea. However, the MRI features are also similar in both disorders. They are ultimately diagnosed by chromosome testing, but there is a possibility of misdiagnosis if chromosome testing is not performed. This study aimed to identify MRI features that are useful for differentiating CAIS from MRKHS. METHOD: This multicenter retrospective study included 12 patients with CAIS and 19 patients with MRKHS. Three radiologists blindly evaluated the following features: (1) detection of vagina, (2) detection of nodular and cystic structures in the lateral pelvis; undescended testicles and paratesticular cysts in CAIS and rudimentary uteri and ovaries in MRKHS, (3) their location, (4) number of cysts in the cystic structures, and (5) signal intensity on diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) values of the nodular structures. Statistical comparisons were performed using Mann-Whitney U and Fisher's exact tests. RESULTS: Compared with MRKHS, the CAIS group showed significantly detectable vagina, more ventrally located nodular and cystic structures, fewer cysts within the cystic structures, and nodular structures with higher signal intensity on DWI and lower ADC values. CONCLUSIONS: MRI features of detectable vagina, location of nodular and cystic structures, number of cysts within the cystic structures, signal intensity on DWI and ADC values of the nodular structures were useful in differentiating CAIS from MRKHS.

A case of mild partial androgen insensitivity syndrome in a juvenile boy.

Androgen insensitivity syndrome (AIS) is a rare disorder with X-linked recessive inheritance in 46 XY patients. The clinical manifestations vary between patients, especially regarding external genitalia development. Herein, the case of AIS in a 13-year-old male, who was born with hypospadias and presented to the hospital with gynaecomastia that had developed from 8 years of age, is reported. No micropenis, cryptorchidism or bifid scrotum were found. Testis volume was 12 ml on both sides. His testosterone and luteinizing hormone levels were normal compared with sex- and age-adjusted reference range. His bone age was approximately 13 years according to Greulich-Pyle assessment. Sequence analysis of the androgen receptor (AR) gene revealed a mutation (c.2041A>G) in exon 4, a novel mutation site in the AR gene. Prediction analysis suggested this to be a disease-causing variant. A milder clinical presentation and normal hormone levels in cases of partial AIS might differ from the usually reported signs and symptoms. A diagnosis of AIS should not be ignored in teenage patients who present with gynaecomastia and hypospadias, but normal hormone levels.

MYRF mutation leads to a single manifestation of sexual development and mimics partial androgen insensitivity syndrome: a case report and literature review.

OBJECTIVE: To highlight the challenges in diagnosing 46, XY disorder of sex development related to MYRF mutation. METHODS: We present an unusual case of a 12-year-old female child came for enlargement of clitoris and initially diagnosed as partial androgen insensitivity syndrome (AIS). RESULTS: On examination, the patient's vulva was found virilized with 3cm-long clitoris. Her peripheral blood karyotype was 46, XY. The ultrasound showed an empty pelvis and hormone results confirmed hyperandrogenism. Therefore, the partial AIS was suspected, but the following whole exon sequencing indicates a pathological missense mutation in MYRF. Further investigation and surgery did not reveal any brain, heart, lung or diaphragm lesions related to MYRF, but only maldeveloped internal genitalia and a persistent urachus. Her serum testosterone dropped to normal after surgical removal of the remaining ipsilateral testis and epididymitis without spermatogenesis as shown by pathology. CONCLUSION: Due to the karyotype, hyperandrogenism, empty pelvis but a virilism after puberty, the patient was initially diagnosed as partial AIS. This misleading clinical diagnose will not be verified as the MYRF mutation if without the whole exon sequencing, particularly in the absence of obvious brain, heart, lung and diaphragm lesions as in this case.

Adult Outcome After Partial Androgen Insensitivity Syndrome: Diagnosed and Assigned Female in Infancy.

This patient, now in her 40s, was evaluated because of genital ambiguity and diagnosed with pAIS in infancy based upon elevated testosterone and gonadotropin levels and significantly reduced binding affinity of the androgen receptor. Such reduced binding is consistent with a structural abnormality of the receptor protein precluding expected activity of the androgen receptor. Based on this information and counseling, her parents chose a female sex assignment. She had clitoral recession and testes removal as an infant and neovaginal surgery using a distal ileum segment at age 11 years and was begun on estrogen therapy at age 12 years. She is being reported now to point out that the data known at her birth provided as specific information to guide sex assignment and genital surgery as is currently available. More importantly, long-term outcome data is very positive showing clear female gender identity, successful marriage of more than 20 years, excellent social relationships including family and friends, an active social life. Since this diagnosis is lifelong, it is inevitable that there will be reminders, hopefully rare, that may be traumatizing. Unfortunately, in this patient, such reminders have been related to access to health care.

Androgen Insensitivity Syndrome with Bilateral Gonadal Sertoli Cell Lesions, Sertoli-Leydig Cell Tumor, and Paratesticular Leiomyoma: A Case Report and First Systematic Literature Review.

Androgen insensitivity syndrome (AIS) is a rare Mendelian disorder caused by mutations of the androgen receptor (AR) gene on the long arm of the X chromosome. As a result of the mutation, the receptor becomes resistant to androgens, and hence, karyotypically male patients (46,XY) carry a female phenotype. Their cryptorchid gonads are prone to the development of several types of tumors (germ cell, sex cord stromal, and others). Here, we report a 15-year-old female-looking patient with primary amenorrhea who underwent laparoscopic gonadectomy. Histologically, the patient's gonads showed Sertoli cell hamartomas (SCHs) and adenomas (SCAs) with areas of Sertoli-Leydig cell tumors (SLCTs) and a left-sided paratesticular leiomyoma. Rudimentary Fallopian tubes were also present. The patient's karyotype was 46,XY without any evidence of aberrations. Molecular genetic analysis of the left gonad revealed two likely germline mutations-a pathogenic frameshift deletion in the AR gene (c.77delT) and a likely pathogenic missense variant in the RAC1 gene (p.A94V). Strikingly, no somatic mutations, fusions, or copy number variations were found. We also performed the first systematic literature review (PRISMA guidelines; screened databases: PubMed, Scopus, Web of Science; ended on 7 December 2023) of the reported cases of patients with AIS showing benign or malignant Sertoli cell lesions/tumors in their gonads (n = 225; age: 4-84, mean 32 years), including Sertoli cell hyperplasia (1%), Sertoli cell nodules (6%), SCHs (31%), SCAs (36%), Sertoli cell tumors (SCTs) (16%), and SLCTs (4%). The few cases (n = 14, 6%; six SCAs, four SCTs, two SLCTs, and two SCHs) with available follow-up (2-49, mean 17 months) showed no evidence of disease (13/14, 93%) or died of other causes (1/14, 7%) despite the histological diagnosis. Smooth muscle lesions/proliferations were identified in 19 (8%) cases (including clearly reported rudimentary uterine remnants, 3 cases; leiomyomas, 4 cases). Rudimentary Fallopian tube(s) were described in nine (4%) cases. Conclusion: AIS may be associated with sex cord/stromal tumors and, rarely, mesenchymal tumors such as leiomyomas. True malignant sex cord tumors can arise in these patients. Larger series with longer follow-ups are needed to estimate the exact prognostic relevance of tumor histology in AIS.

Congenital malformations of the female genital organs.

Congenital malformations of the female genital organs are rare anomalies and their incidence is estimated to be up to 7% in the general population. Müllerian ducts abnormalities are one of the causes of infertility and occur in approximately 16% of women with recurrent miscarriages. Sex development disorders are diagnosed at different stages of the patient's life depending on the accompanying ailments. Alarming signs of genital malformations include primary amenorrhea or dysmenorrhea, dyspareunia, and periodic abdominal pain.

Complete androgen insensitivity syndrome diagnosed after inguinal surgery in era of modern technology: a case report.

Introduction: Androgen Insensitivity Syndrome (AIS) is a rare X-linked recessive disorder of sexual development. It results from mutations in the Androgen Receptor (AR) gene located on chromosome Xq11-12. Affected individuals have a male genotype but a female phenotype. Case presentation: A 20-year-old female presented to the emergency room with a history of pain in the bilateral inguinal region. In ultrasonography (USG), bilateral inguinal hernia was suspected. While performing an emergency operation for hernia repair, hernia was revealed as bilateral abdominal testis. Then, after a gynecology consultation, a bilateral orchidectomy was done. Postoperative karyotyping showed a male genotype. Then the patient was discharged on hormone replacement therapy to maintain normal bone mineral density and secondary sexual characteristics. Discussion: AIS presents with primary amenorrhea in pubertal females. The growth spurt and secondary sexual characteristics are normal except for absent axillary and pubic hair. There is a short-blind vagina, but the uterus is absent, and the abdominal testis presents as an inguinal hernia. Serum gonadotropin level, karyotyping, and imaging studies are done to reach a diagnosis. Management includes gonadectomy, genitoplasty, and hormone replacement therapy. Conclusion: The objective of this report was to make clinicians aware that AIS can present as a bilateral inguinal hernia. In acute presentations, it can be misdiagnosed as a strangulated femoral hernia only later to be identified as an undescended abdominal testis during surgery. An absence of proper clinical judgment and reliance on USG for imaging can often lead to misdiagnosis in acute settings.

Urethral reconstruction using amniotic membrane allograft in hereditary androgen insensitivity syndrome: a case series.

Partial androgen insensitivity syndrome is a rare X-linked disorder. While most cases are sporadic, familial cases are less frequent. The management of this syndrome follows a multidisciplinary approach involving hormone substitution, psychological counseling, and surgical procedures. We present a case series of three young siblings with familial partial androgen insensitivity syndrome who presented with a female phenotype. All of them were managed with hormonal treatment for 6 months followed by surgical reconstruction. The operative procedure involved phalloplasty and urethroplasty using amniotic membrane transplant, which is considered a novel technique in this group of patients. No intraoperative or postoperative complications were observed and good results were achieved within 2 years of follow-up.

A Baby With Complete Androgen Insensitivity Syndrome and the Fortuitous Discovery of 45,X/46,XY Mosaicism.

Disorders of sex development (DSD) are caused by defects in the complex sexual differentiation cascade, resulting in discordance among an individual's genetic, gonadal, and genital sexes. It affects one in 4,500 live births. A wide spectrum of genital phenotypes can be found depending on the underlying pathogenic mechanism and the developmental stage that is affected. We herein report a newborn with female external genitalia but palpable gonads at labia majora with normal testicular function and structure, which is typical of complete androgen insensitivity syndrome (CAIS). The genetic study revealed 45,X/46,XY mosaicism and c.2081A>C missense androgen receptor gene mutation, indicating the likelihood of co-existing CAIS. This case demonstrated the importance of correlating genital phenotype and the underlying pathogenic mechanism, to provide appropriate management of DSD. Important considerations on managing the gonads about the risks of gonadal malignancies are also discussed.

Small Indels in the Androgen Receptor Gene: Phenotype Implications and Mechanisms of Mutagenesis.

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.

Androgen Insensitivity Syndrome DUE to Non-Coding Variation in the Androgen Receptor Gene: Review of the Literature and Case Report of a Patient with Mosaic c.-547C>T Variant.

Sexual development (SD) is a complex process with strict spatiotemporal regulation of gene expression. Despite advancements in molecular diagnostics, disorders of sexual development (DSD) have a diagnostic rate of ~50%. Androgen insensitivity syndrome (AIS) represents the most common form of 46,XY DSD, with a spectrum of defects in androgen action. Considering the importance of very strict regulation of the SD, it is reasonable to assume that the genetic cause for proportion of the DSD lies in the non-coding part of the genome that regulates proper gene functioning. Here we present a patient with partial AIS (PAIS) due to a mosaic de novo c.-547C>T pathogenic variant in the 5'UTR of androgen receptor (AR) gene. The same mutation was previously described as inherited, in two unrelated patients with complete AIS (CAIS). Thus, our case further confirms the previous findings that variable gene expressivity could be attributed to mosaicism. Mutations in 5'UTR could create new upstream open reading frames (uORFs) or could disrupt the existing one. A recent systematic genome-wide study identified AR as a member of a subset of genes where modifications of uORFs represents an important disease mechanism. Only a small number of studies are reporting non-coding mutations in the AR gene and our case emphasizes the importance of molecular testing of the entire AR locus in AIS patients. The introduction of new methods for comprehensive molecular testing in routine genetic diagnosis, accompanied with new tools for in sillico analysis could improve the genetic diagnosis of AIS, and DSD in general.