Predictors of surgical complications in boys with hypospadias: data from an internationa registry

Background

Complications are frequently reported after hypospadias repair and there is a need to understand the factors that influence their occurrence.

Methods

Data from boys with hypospadias born between 2000 and 2020 were obtained from the International Disorders of Sex Development (I-DSD) Registry. Logistic regressions, fisher's exact tests and spearman's correlation tests were performed on the data to assess associations between clinical factors and complication rates.

Results

Of the 551 eligible boys, data were available on 160 (29%). Within the cohort, the median (range) External Masculinization Score (EMS) was 6 (2, 9). All presented with one or more additional genital malformation and 61 (38%) presented with additional extragenital malformations. Disorders of androgen action, androgen synthesis and gonadal development were diagnosed in 28 (18%), 22 (14%) and 9 (6%) boys, respectively. The remaining 101 (62%) patients were diagnosed as having non-specific 46,XY Disorders of Sex Development. Eighty (50%) boys had evidence of abnormal biochemistry, and gene variants were identified in 42 (26%). Median age at first hypospadias surgery was 2 years (0, 9), and median length of follow-up was 5 years (0, 17). Postsurgical complications were noted in 102 (64%) boys. There were no significant associations with postsurgical complications.

Conclusions

Boys with proximal hypospadias in the I-DSD Registry have high rates of additional comorbidities and a high risk of postoperative complications. No clinical factors were significantly associated with complication rates. High complication rates with no observable cause suggest the involvement of other factors which need investigation.

Delivery of multidisciplinary care in the field of differences and disorders of sex development (DSD)

INTRODUCTION

Differences and disorders of sex development (DSD) are a diverse group of conditions, which often present in early childhood and may require input from a group of experts in a wide range of clinical fields. Clinical guidance in this field recommends that these experts function as a multidisciplinary team (MDT) within which each expert has a defined role, which ensures an integrated and streamlined approach to the care of affected individuals.

AREAS COVERED

This review will focus on the benefits of multidisciplinary care for people with DSD, as well as the challenges that may be faced.

EXPERT OPINION

Core members of the MDT for people with DSD include endocrinologists, surgeons, psychologists, geneticists, specialist nurses, radiologists, and gynecologists, although many other health-care professionals may also be pertinent, at different stages of the patient's life. With greater acceptance of remote and digital health-care technology, there is a need to review the traditional concepts of the clinical MDT so that new care models can be explored for effective and efficient delivery of complex care.

Differences in the autocatalytic cleavage of pro-PC2 and pro-PC3 can be attributed to sequences within the propeptide and Asp310 of pro-PC2

PC2 and PC3 are subtilisin-like proteases involved in the maturation of prohormones and proneuropeptides within neuroendocrine cells. They are synthesized as zymogens that undergo autocatalytic maturation within the secretory pathway. Maturation of pro-PC2 is slow (t12 >8 h), exhibits a pH optimum of 5.5 and is dependent on calcium (K0.5 2 mM), while pro-PC3 maturation is relatively rapid (t12 15 min), exhibits a neutral pH optimum and is not calcium dependent. These differences in the rates and optimal conditions for activation of the proteases may contribute to the diversity of products generated by these proteases in different cell types. Although highly similar, there are two major differences between pro-PC2 and pro-PC3: the presence of an aspartate at position 310 in pro-PC2 compared with asparagine at the equivalent position in pro-PC3 (and all other members of the subtilisin family), and the N-terminal propeptides, which exhibit low sequence identity (30%). With a view to establishing the structural features that might be responsible for these differences in the maturation of pro-PC2 and pro-PC3, Asp310 in pro-PC2 was mutated to Asn, and Asn309 in pro-PC3 was mutated to Asp. Chimaeric proteins were also made consisting of the pro-region of PC2 fused to the mature portion of PC3 and the pro-region of PC3 fused to the mature region of PC2. The wild-type and mutant DNA constructs were then transcribed and translated in an in vitro system capable of supporting maturation of pro-PC2 and pro-PC3. The results demonstrated that Asp310 of pro-PC2 is responsible for the acidic pH optimum for maturation. Thus changing Asp310 to Asn shifted the pH optimum for maturation to pH 7.0. However, changing Asn309 of pro-PC3 to Asp had no effect on the optimum pH for maturation of pro-PC3. A chimaeric construct containing the propeptide of pro-PC2 attached to PC3 shifted the pH optimum for maturation from pH 7.0 to 6.0 and slowed down the rate of maturation (t12 >8 h). When attached to PC2, the pro-region of pro-PC3 had no effect on the optimum pH for maturation (pH 5.5-6.0), but it did accelerate the rate of maturation (t12 2 h). These results demonstrate that Asp310 and the pro-region of pro-PC2 contribute to the acidic pH optimum and low rate of maturation of this zymogen relative to its closely related homologue PC3.