Genetics and phenotyping of urological chronic pelvic pain syndrome

Abstract

Purpose: Interstitial cystitis/painful bladder syndrome and chronic prostatitis/chronic pelvic pain syndrome, collectively renamed urological chronic pelvic pain syndromes, are a group of medically unexplained physical symptoms. Diagnosis depends on excluding all possible causes of pain and treatment targets symptoms alone. An emerging body of research implicates systemic factors in the pathogenesis of urological chronic pelvic pain syndromes including abnormal sympathetic nervous system and hypothalamic-pituitary-adrenal axis activity. Several new lines of evidence also suggest a genetic component to disease pathogenesis. Despite ongoing efforts, neither effective treatments nor mechanistic understanding of the pathogenesis of urological chronic pelvic pain syndromes exists.

Materials and methods: We performed a survey of the available literature on urological chronic pelvic pain syndromes. We reviewed recent research implicating genetic mechanisms in the development of urological chronic pelvic pain syndromes to find a systematic approach of rigorous phenotyping on which to base further investigation of these chronic pain conditions.

Results: Three studies revealed identifying genetic risk factors for disease. In addition, increasing lines of evidence of familial clustering and twin studies suggested a genetic basis for disease.

Conclusions: Given the success of genome-wide association studies in quantifying genetic risk in several polygenic diseases, we suggest a similar genome-wide approach to the study of urological chronic pelvic pain syndromes. As genome-wide association studies depend on carefully defined patient populations, we provide an outline for a thorough and multidisciplinary characterization of patient phenotypes. Although urological chronic pelvic pain syndromes continue to mystify clinicians and researchers alike, we believe the powerful new methods of unbiased interrogation of the whole genome based on systematically grouped patients possess enormous potential for progress in treating and understanding this disease.

Figure

Schematic representation of patient phenotyping in UCPPS. Patients meeting standard diagnostic criteria should be characterized as objectively as possible according to brain fMRI, complete review of symptoms, HPA/SNS score, adrenocortical evaluation and protein biomarkers identified in previous studies. Selective grouping of patients according to this system will increase power of GWAS for new genetic targets. CRF, corticotropin-releasing factor. MFI-20, Multidimensional Fatigue Inventory. MR, magnetic resonance. PET, positron emission tomography.