Two Korean girls with complete androgen insensitivity syndrome diagnosed in infancy

Clinical outcomes and genotype-phenotype correlations in patients with complete and partial androgen insensitivity syndromes

PURPOSE

Androgen insensitivity syndrome (AIS) is a rare X-linked recessive disorder caused by unresponsiveness to androgens because of mutations in the AR gene. Here, we investigated the clinical outcomes and molecular spectrum of AR variants in patients with AIS attending a single academic center.

METHODS

This study included 19 patients with AIS who were confirmed by molecular analysis of AR. Clinical features and endocrinological findings were retrospectively collected, including presenting features, external genitalia, sex of rearing, timing of gonadectomy, pubertal outcomes, and sex hormone levels. Molecular analysis of AR was performed using Sanger, targeted gene panel, or whole-exome sequencing.

RESULTS

Among all 19 patients, 14 (74%) were classified as having complete AIS (CAIS), whereas 5 (26%) had partial AIS (PAIS). All patients with CAIS, and 3 patients with PAIS were reared as female. One patient with CAIS manifested a mixed germ cell tumor at the age of 30 years. Molecular analysis of AR identified 19 sequence variants; 12 (63%) were previously reported, and the remaining 7 (37%) were novel. Missense mutations were the most common type (12 of 19, 63%), followed by small deletions, nonsense mutations, an insertion, and a splice site mutation.

CONCLUSION

Here, we describe the clinical outcomes and molecular characteristics of 19 Korean patients with AIS. Patients with PAIS manifested various degrees of masculinization of the external genitalia. Nonsense and frameshift mutations were frequent in patients with CAIS, whereas patients with PAIS harbored exclusively missense mutations.

Novel pathogenic variants in the androgen receptor gene associated with androgen insensitivity syndrome identified through exome sequencing and in silico analysis

Androgen insensitivity syndrome (AIS) is a common disorder/differences of sex development with a 46, XY karyotype, but diverse genital phenotypes. Various pathogenic variants within the androgen receptor (AR) gene on the X chromosome are the primary pathogenesis of AIS. However, some patients with AIS still lack a definitive molecular diagnosis. Here, molecular diagnosis of eight patients with the clinical phenotype of AIS was performed using exome sequencing. We found eight variants of the AR gene, including p.(C131*), p.(W435*), p.(T653Lfs*8), c.2318+1G>T, p.(S397R), p.(Y572C), p.(S648G), and p.(D691G), and a pathogenic copy number variation covering a deletion of exon 2 of AR gene. Patient pedigree validation confirmed that the discovered variants conformed to the X-linked recessive inheritance patterns of AIS. In silico analysis indicated that the splice site variant (c.2318+1G>T) could lead to loss of the original 5' splice donor site and exon skipping. Missense variants, including p.(S397R), p.(S648G), and p.(D691G), may affect the structure and function of the AR protein. Our results highlight the applicability of exome sequencing for molecular diagnosis of AIS. The novel variants found in this study enrich the pathogenic variant spectrum of the AR gene and provide a basis for the diagnosis and management of patients with AIS. A definite molecular diagnosis will provide accurate guidance for genetic counseling of proband's family members.

"Waking up" the sleeping metaphor of normality in connection to intersex or DSD: a scoping review of medical literature

The aim of the study is to encourage a critical debate on the use of normality in the medical literature on DSD or intersex. For this purpose, a scoping review was conducted to identify and map the various ways in which "normal" is used in the medical literature on DSD between 2016 and 2020. We identified 75 studies, many of which were case studies highlighting rare cases of DSD, others, mainly retrospective observational studies, focused on improving diagnosis or treatment. The most common use of the adjective normal was in association with phenotypic sex. Overall, appearance was the most commonly cited criteria to evaluate the normality of sex organs. More than 1/3 of the studies included also medical photographs of sex organs. This persistent use of normality in reference to phenotypic sex is worrisome given the long-term medicalization of intersex bodies in the name of a "normal" appearance or leading a "normal" life. Healthcare professionals should be more careful about the ethical implications of using photographs in publications given that many intersex persons describe their experience with medical photography as dehumanizing.

Molecular study and genotype-phenotype in Chinese female patients with 46, XY disorders of sex development

OBJECTIVE

The rare condition 46, XY disorders of sex development (DSDs) is characterized by the female phenotype and male karyotype. We aimed to describe the genetic basis of 46, XY DSDs in nine patients and the genotype-phenotype relationships of the genes involved.

METHODS

Targeted next-generation sequencing (NGS) was used to analyze the underlying hereditary etiology in nine female patients with 46, XY DSDs. In silico analyses were used to predict the effects of novel variants on the protein function of the identified genes.

RESULTS

Primary amenorrhea with the absence of puberty, inguinal hernia, and clitoridauxe were common complaints. All enrolled patients had a differential etiology by genetic testing, and five novel genetic variants involved in four genes (SRY, AR, NR5A1, and LHCGR) were identified. A novel nonsense variant of SRY c.51C > G was found in XY patients without testicles. Two novel heterozygous variants, i.e. c.265A > T (Ile89Leu) and c.422T > C (Val141Ala), of the LHCGR gene were found in male pseudo-hermaphroditism.

CONCLUSIONS

We expanded the genetic mutation spectrum and described in detail the genotype-phenotype relationships of 46, XY DSDs. DNA sequencing for SRY should be a priority in female patients with 46, XY DSDs. NGS is useful for clarifying genetic pathogenesis and could provide a basis for clinical diagnosis and treatments of patients with 46, XY DSDs.

Six novel Mutation analysis of the androgen receptor gene in 17 Chinese patients with androgen insensitivity syndrome

BACKGROUND

Androgen insensitivity syndrome (AIS) is the most common type of 46, XY disorders of sex development (DSD), with a wide range of clinical heterogeneity, from male infertility, hypospadias to completely normal female external genitalia. Mutation of the androgen receptor (AR) gene on the X chromosome (Xq11.2q12) is the main cause of AIS.

METHODS

By phenotype evaluation, hormone test, ultrasound scan and G-banding karyotype, 17 unrelated Chinese patients were clinical diagnosed with AIS. Sanger sequencing of the AR was performed in these 17 patients. Functional studies were carried out for the novel mutations.

RESULTS

We identified 16 mutations in all patients, including six novel mutations (Q59*, F171Sfs*4, E204*, G209E, I870T, *921R). It is the first time that a stop codon mutation (*921R) in AR has been identified. Expression and nuclear localization analysis showed the *921R mutation caused an elongated abnormal polypeptide chain of the AR protein, and the abnormal protein could not be transported to the nucleus to stimulate the expression of downstream genes after androgenic treatment. Expression analysis showed the protein level of G209E mutation was obviously decreased.

CONCLUSION

Our study expands the spectrum of AR mutations and could provide evidence for the genetic and reproductive counseling of families with AIS. All of these findings broadened the mutation spectrum of AR, which were significantly valuable for patient gender assignment, genetic counseling and the clinical and psychological management.