8610 The Role of Adenylyl Cyclase 2 Gene-Dosage Changes in Congenital Male Genitourinary Anomalies

Abstract

Abstract Disclosure: D.J. Lamb: Advisory Board Member; Self; Ro Health, Inc. Stock Owner; Self; Fellow Health, Inc. M.A. O'Neill: None. Collectively, congenital genitourinary (GU) birth defects are the most common birth defects in males, yet relatively little is known about their cause. In part, this reflects the current clinical perspective that, because most of these birth defects can be surgically repaired, there is nothing to be gained by understanding the cause. Yet our studies show that seemingly simple birth defects like hypospadias or cryptorchidism, may be associated with other more significant underappreciated defects, such as those affecting the kidney, heart, eyes or behavior. We tested the hypothesis that chromosome microdeletions and microduplications (called copy number variations, CNVs) result in gene-dosage changes that are important regulators of GU development and when haploinsufficient or duplicated normal genitourinary development is impacted causing birth defects of the upper and/or lower genitourinary tract. We successfully used this strategy to identify 15 different previously unrecognized genes that when microduplicated or microdeleted result in conditions such as cryptorchidism, hypospadias, disorders of sexual differentiation (DSD) and other anomalies. Remarkably, gene-dosage changes affected major signaling pathways and post-translational modifications in novel, previously unrecognized ways. Herein, we focused on defining the role of a candidate gene commonly microdeleted or microduplicated in patients with cryptorchidism, hypospadias and/or micropenis. Locus mapping allowed identification of adenylate cyclase 2 (ADCY2) as a candidate gene at the 5p15.31 Cri-du-Chat region in patients with male genital tract anomalies. ADCY2 CNVs were more common in non-syndromic patients with micropenis, cryptorchidism, and/or hypospadias (1.6%) than the general population (0.07%; p< 0.001). Whole exome sequence studies revealed a range of phenotypic anomalies in patients with damaging and potentially damaging ADCY2 variants in addition to the male GU anomalies, including congenital anomalies of the kidney and urinary tract. It is our hypothesis that ADCY2 duplications result in a de-sensitization of the LH receptor diminishing testosterone biosynthesis in the testis, whereas deletions diminish LH receptor signaling. ADCY2 CNVs were assessed in 100 men with spermatogenic failure who were born with cryptorchidism. The ADCY2 CNV frequency was the same as in our cohort of boys with GU anomalies, but as adults they also have hypergonadotropic hypogonadism, which we predicted if ADCY2 over-expression was impacting adult Leydig cell steroidogenesis through partial desensitization of the LH receptor. These studies identified an unrecognized cause of GU anomalies. In the future, such knowledge may lead to improved diagnosis and therapeutic approaches to ameliorate these common birth defects. Presentation: 6/2/2024