Different types of androgen receptor mutations in patients with complete androgen insensitivity syndrome

Novel androgen receptor gene variant containing a frameshift mutation in a patient with complete androgen insensitivity syndrome

A variety of mutations in the androgen receptor (AR) gene are linked to androgen insensitivity syndrome (AIS). AIS is the most common specific cause of 46, XY disorder in sex development. Here, we reported a patient which presented as a female with 46, XY karyotype and normal female external genitalia. The patient was diagnosed with complete AIS caused by a novel mutation (NM_000044, c.2678-2726del, p. Pro893Leufs*35) in the AR gene. Targeted exome sequencing was used to detect the patient's androgen receptor gene mutations. Sanger sequencing was used to validate the mutation. This study showed that a novel mutation of the AR gene can cause complete AIS; the study also broadened the AR mutation spectrum and indicated that targeted exome sequencing could help facilitate the diagnosis of complicated disorders in sexual development.

Novel Androgen Receptor Gene Variant Containing a Premature Termination Codon in a Patient with Androgen Insensitivity Syndrome

BACKGROUND

Androgen receptor (AR) mutations, which cause androgen insensitivity syndrome, impair the actions of 5α-dihydrotestosterone and testosterone, resulting in abnormal sexual development. In most cases, genetic aberrations of the AR are caused by substitutions, but also can result from mutations in splicing regions and deletions in the AR gene.

CASE

Our present report describes a female patient with 46,XY karyotype and normal female external genitalia. A novel de novo c.1669_1670insC insertion in the AR gene caused androgen insensitivity syndrome.

SUMMARY AND CONCLUSION

This report provides a detailed clinical characterization of the patient and a possible pathogenic mechanism leading to androgen insensitivity syndrome and should be particularly useful in genetic counseling.

Novel Mutations Segregating with Complete Androgen Insensitivity Syndrome and their Molecular Characteristics

We analyzed three cases of Complete Androgen Insensitivity Syndrome (CAIS) and report three hitherto undisclosed causes of the disease. RNA-Seq, Real-timePCR, Western immunoblotting, and immunohistochemistry were performed with the aim of characterizing the disease-causing variants. In case No.1, we have identified a novel androgen receptor (AR) mutation (c.840delT) within the first exon in the N-terminal transactivation domain. This thymine deletion resulted in a frameshift and thus introduced a premature stop codon at amino acid 282. In case No.2, we observed a nonsynonymous mutation in the ligand-binding domain (c.2491C>T). Case No.3 did not reveal AR mutation; however, we have found a heterozygous mutation in CYP11A1 gene, which has a role in steroid hormone biosynthesis. Comparative RNA-Seq analysis of CAIS and control revealed 4293 significantly deregulated genes. In patients with CAIS, we observed a significant increase in the expression levels of PLCXD3, TM4SF18, CFI, GPX8, and SFRP4, and a significant decrease in the expression of SPATA16, TSACC, TCP10L, and DPY19L2 genes (more than 10-fold, p < 0.05). Our findings will be helpful in molecular diagnostics of patients with CAIS, as well as the identified genes could be also potential biomarkers for the germ cells differentiation process.

Effects of chromosomal sex and hormonal influences on shaping sex differences in brain and behavior: Lessons from cases of disorders of sex development

Sex differences in brain development and postnatal behavior are determined largely by genetic sex and in utero gonadal hormone secretions. In humans however, determining the weight that each of these factors contributes remains a challenge because social influences should also be considered. Cases of disorders of sex development (DSD) provide unique insight into how mutations in genes responsible for gonadal formation can perturb the subsequent developmental hormonal milieu and elicit changes in normal human brain maturation. Specific forms of DSDs such as complete androgen insensitivity syndrome (CAIS), congenital adrenal hyperplasia (CAH), and 5α-reductase deficiency syndrome have variable effects between males and females, and the developmental outcomes of such conditions are largely dependent on sex chromosome composition. Medical and psychological works focused on CAH, CAIS, and 5α-reductase deficiency have helped form the foundation for understanding the roles of genetic and hormonal factors necessary for guiding human brain development. Here we highlight how the three aforementioned DSDs contribute to brain and behavioral phenotypes that can uniquely affect 46,XY and 46,XX individuals in dramatically different fashions. © 2016 Wiley Periodicals, Inc.

A novel variant of androgen receptor is associated with idiopathic azoospermia

A variety of genetic variants can lead to abnormal human spermatogenesis. The androgen receptor (AR) is an important steroid hormone receptor that is critical for male sexual differentiation and the maintenance of normal spermatogenesis. In the present study, each exon of AR in 776 patients diagnosed with idiopathic azoospermia (IA) and 709 proven fertile men were sequenced using use panel re‑sequencing methods to examine whether AR is involved in the pathogenesis of IA. Two synonymous variants and seven missense variants were detected. Of the missense variants, a luciferase assay demonstrated that the R630W variant reduced the transcriptional regulatory function of AR. This novel variant (p. R630W) of AR is the first to be identified in association with IA, thereby highlighting the importance of AR during spermatogenesis.