The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca²⁺ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function.

Disorders of sex development (DSD) consist of a wide range of disorders and are commoner in those with an XY karyotype. In over half of these cases who have a 46,XY karyotype and who are raised as boys, the underlying aetiology remains unclear. Identification of the underlying genetic abnormality may predict long-term outcome. However, genetic abnormalities that are associated with XY DSD manifest themselves with a wide range of phenotype. To understand the aetiology as well as the phenotypic variation, there is a need to harness the advanced genetic technology that is now available. The point at which genetic analysis should be undertaken in the course of investigations is unclear. In addition, there is little agreement on the most effective approach for genetic analysis that will be of clinical benefit to the patient. There is a need to understand and improve the clinical utility of genetic analysis in the clinical setting of the patient with a suspected DSD. This will be even more important when parallel gene sequencing identifies variations in multiple genes.

Background: In boys with suspected partial androgen insensitivity syndrome (PAIS), systematic evidence that supports the long-term prognostic value of identifying a mutation in the androgen receptor gene (AR) is lacking. Objective: To assess the clinical characteristics and long-term outcomes in young men with suspected PAIS in relation to the results of AR analysis. Methods: Through the International Disorders of Sex Development Registry, clinical information was gathered on young men suspected of having PAIS (n = 52) who presented before the age of 16 years and had genetic analysis of AR. Results: The median ages at presentation and at the time of the study were 1 month (range, 1 day to 16 years) and 22 years (range, 16 to 52 years), respectively. Of the cohort, 29 men (56%) had 20 different AR mutations reported. At diagnosis, the median external masculinization scores were 7 and 6 in cases with and without AR mutation, respectively (P = .9), and median current external masculinization scores were 9 and 10, respectively (P = .28). Thirty-five men (67%) required at least one surgical procedure, and those with a mutation were more likely to require multiple surgeries for hypospadias (P = .004). All cases with an AR mutation had gynecomastia, compared to 9% of those without an AR mutation. Of the six men who had a mastectomy, five (83%) had an AR mutation. Conclusions: Boys with genetically confirmed PAIS are likely to have a poorer clinical outcome than those with XY DSD, with normal T synthesis, and without an identifiable AR mutation. Routine genetic analysis of AR to confirm PAIS informs long-term prognosis and management.

Background: Complete and partial androgen insensitivity syndrome (CAIS, PAIS) are associated with an increased risk of gonadal germ cell cancer (GGCC). Recent guidelines recommend gonadectomy in women with CAIS in late adolescence. Nevertheless, many adult women prefer to retain their gonads. Aims: This study aims to explore attitudes towards gonadectomy in AIS in centres around the world, estimate the proportion of adults with retained gonads and/or who developed GGCC, and explore reasons for declining gonadectomy. Methods: A survey was performed among health care professionals who use the International DSD Registry (I-DSD). Results: Data were provided from 22 centres in 16 countries on 166 women (CAIS) and 26 men (PAIS). In CAIS, gonadectomy was recommended in early adulthood in 67% of centres; 19/166 (11.4%) women refused gonadectomy. Among 142 women who had gonadectomy, evidence of germ cell neoplasm in situ (GCNIS), the precursor of GGCC, was reported in 2 (1.4%) out of 8 from whom pathology results were formally provided. Nine out of 26 men with PAIS (34.6%) had retained gonads; 11% of centres recommended routine gonadectomy in PAIS. Conclusion: Although development of GGCC seems rare, gonadectomy after puberty is broadly recommended in CAIS; in PAIS this is more variable. Overall, our data reflect the need for evidence-based guidelines regarding prophylactic gonadectomy in AIS.

OBJECTIVES: This study aimed to identify the prevalence and characteristics of rib fractures in ex-preterm infants. METHODS: Infants born at <37 weeks’ gestation and admitted before 2011 to 3 regional neonatal units were identified from admission registers. For 2 centers, these data were available from 2000 onward and, for another center, from 2005. Electronic records were searched to identify chest radiographs performed up to age 1 year. Chest radiograph reports were then reviewed for evidence of rib fractures, and the case notes of all affected individuals were scrutinized. RESULTS: Of the 3318 eligible preterm infants, 1446 had a total of 9386 chest radiographs. Of these infants, 26 (1.8%) were identified as having a total of 62 rib fractures. Their median (range) gestation at birth was 26 weeks (23–34). The median chronological age of these infants at the time of the radiograph was 14 weeks (5 weeks to 8 months). The median corrected gestational age at the time of the radiograph was 39 weeks (34 weeks to 4 months). Of the 62 fractures, 27 (36%) were sited posteriorly, and 15 (53%) of the infants with posterior rib fractures were diagnosed with osteopathy of prematurity. Classic risk including conjugated hyperbilirubinemia and diuretics, were present in 23 of 26 (88%) infants. A full skeletal survey was performed in 8 of 26 (31%). Investigations for nonaccidental injury occurred in 4 of 26 (15%) cases. CONCLUSIONS: Evidence of rib fractures is present in ∼2% of ex-preterm infants. The evaluation of these fractures in infancy requires a detailed neonatal history irrespective of the site of rib fracture.

The commitment of the embryonic gonad towards the male or female fate is a sequential and complex developmental process. The sex-independent growth and development of the adrenogonadal primordium into the bipotential gonadal ridge is committed to the formation of testis in the presence of the SRY gene on the Y chromosome. SRY upregulates the expression of SOX9 that sets into motion a cascade of complex genetic interactions for the formation of male internal and external genitalia whilst repressing the formation of female genitalia. The initiation and maintenance of somatic sex of the gonad as either male or female is achieved by suppression of the alternate fate. However, at least in mice, the primary sex-determining decision is not final but is maintained in adulthood by a mutually antagonistic double-repressive pathway. In the human, any imbalance between these two antagonistic genetic and physiological pathways results in inappropriate gonad differentiation and function leading to disorders of sex development (DSD). Genetic analysis of individuals presenting with DSD and sex-reversed mice has revealed a number of sexually dimorphic genes that are involved in the formation of mammalian gonads, which are discussed in this chapter. Despite an increase in the knowledge of genes involved in mammalian sex determination, the molecular mechanisms remain by and large undetermined. The use of novel 'omics' technologies for analyzing a large number of patients with DSD, and careful assessment of the resulting datasets may result in the identification of novel genetic factors in human sex determination and lead to the development of novel ex vivo cellular models.