Is joint hypermobility associated with vesico-ureteral reflux? An assessment of 50 patients

Lower urinary tract involvement in Ehlers-Danlos and Joint Hypermobility syndromes: Review of the literature

INTRODUCTION

Ehlers-Danlos syndrome (EDS) and Joint Hypermobility syndrome (JHS) are still poorly understood, with a prevalence of 1/5000 for EDS and 1/500 for JHS. They are characterized by multisystem involvement. Urological involvement has been little studied. The aim was to carry out a review of the literature on the urological involvement of EDS and JHS.

METHOD

A review of the literature was carried out using the following databases: Pubmed, Canadian Hospitals and EMBASE. Search terms were "Ehlers-Danlos" or "Joint Hypermobility" associated with "Urology", "Bladder", "Pelvic Organ Prolapse", "Urinary Retention", "Leak", "Leakage", "Urinary Incontinence", "Urinary Tract Infection" and "Urdodynamic", no filters were added.

RESULTS

Seventy-three articles were included for a total of 259 found. The prevalence of urinary incontinence in EDS is estimated at 50-60%, and that of pelvic organ prolapse (POP) at 29-75%. Bladder diverticula are also frequently reported. For JHS, the prevalence of urinary incontinence is estimated between 40 and 73%, that of POP increased with 73% of stage greater than 2, g-JHS patients are almost 3 times more affected by prolapses (OR=2.37) which seem more severe. Patients with vesicoureteral reflux, most often severe, are more affected by joint hypermobility (OR=2.79). Few studies have been carried out on urological assessment and treatment modalities.

CONCLUSION

EDS patients often have urinary incontinence, pelvic organ prolapse or bladder diverticula. JHS patients frequently have urinary incontinence, pelvic organ prolapse and vesicoureteral reflux.

Excessive laxity of connective tissue in constipated children

Excessive laxity of the connective tissue refers to a group of inherited abnormalities manifested by disturbances in the functioning of internal organs, including the gastrointestinal tract. Increased susceptibility to stretching of the distal part of the large intestine and abnormal colonic motor function could explain the predisposition to the development of functional constipation in some children. Our aim was to determine whether patients with functional constipation are more likely to be characterized by congenital laxity of connective tissue compared to the population of healthy children. Children diagnosed with functional constipation according to the Rome III criteria were prospectively enrolled in the study (study group, S) and compared to otherwise healthy children (control group, C). Excessive laxity of the connective tissue was evaluated using the Beighton Score (BS) and expressed as median and interquartile range (IQR). The study included 411 patients (median age 7.8 years, min 3 years, max 18 years; 49% male), comprising 211 patients in the S group and 200 children in the C group. The median BS in the S group was significantly higher than in the C group (median: 5 points [IQR: 1–4.5] vs 2 points [IQR: 3–7], respectively; p = 0.000). Furthermore, increased connective tissue laxity was observed more frequently in females (p < 0.05). Increased connective tissue laxity was more frequent in children with functional constipation, especially in girls. Excessive laxity of the connective tissue may be one of the etiological factors of functional constipation in children.

Urogenital and pelvic complications in the Ehlers-Danlos syndromes and associated hypermobility spectrum disorders: A scoping review

The Ehlers-Danlos syndromes (EDS) and associated hypermobility spectrum disorders (HSD) are a heterogenous group of connective tissue disorders associated with significant morbidity. The urogenital aspects of these disorders are understudied and there is little guidance on the prevalence, types, or outcomes of urogenital complications in EDS/HSD. Our objective was to perform a scoping review to characterize and synthesize the literature reporting urogenital and pelvic complications in EDS/HSD patients. We performed a systematic search of three databases (Medline, CINAHL, Embase) to January 2019. English language, full-text articles reporting on urogenital or pelvic complications in EDS/HSD were included. A total of 105 studies were included (62 case reports/series, 43 observational) involving patients with hypermobile (23%), vascular (20%), classical (12%) EDS, and HSD (24%). Some studies looked at multiple subtypes (11%) or did not report subtype (33%). Reported complications included urinary (41%), gynecological (36%), obstetrical (25%), renal (9%), and men's health problems (7%), with some studies reporting on multiple areas. Urinary and gynecological complications were most prevalent in patients with HSD, while a broad range of complications were reported in EDS. While further research is required, results suggest a higher index of suspicion for urogenital problems is probably warranted in this population.

Children with vesicoureteric reflux have joint hypermobility and occasional tenascin XB sequence variants

INTRODUCTION

To consider alternative mechanisms that give rise to a refluxing ureterovesical junction (UVJ), we hypothesized that children with a common heritable urinary tract defect, vesicoureteric reflux (VUR), may have a defect in the extracellular matrix composition of the UVJ and other tissues that would be revealed by assessment of the peripheral joints. Hypermobile joints can arise from defects in the extracellular matrix within the joint capsule that affect proteins, including tenascin XB (TNXB).

METHODS

We performed an observational study of children with familial and non-familial VUR to determine the prevalence of joint hypermobility, renal scarring, and DNA sequence variants in TNXB.

RESULTS

Most children (27/44) exhibited joint hypermobility using the Beighton scoring system. This included 15/26 girls (57.7%) and 12/18 boys (66.7%), which is a significantly higher prevalence for both sexes when compared to population controls (p<0.005). We found no association between joint hypermobility and renal scarring. Seven of 49 children harbored rare pathogenic sequence variants in TNXB, and two also exhibited joint hypermobility. No sequence variants in TNXB were identified in 25/27 children with VUR and joint hypermobility. Due to the observational design of the study, there was missing data for joint hypermobility scores in six children and for dimercaptosuccinic acid (DMSA) scans in 17 children.

CONCLUSIONS

We observed a high prevalence of VUR and joint hypermobility in children followed within a tertiary care pediatric urology clinic. While mutations in TNXB have been reported in families with VUR and joint hypermobility, we identified only two children with these phenotypes and pathogenic variants in TNXB. We, therefore, speculate that VUR and joint hypermobility may be due to mutations in other extracellular matrix genes.

Vesicoureteral reflux and the extracellular matrix connection

Primary vesicoureteral reflux (VUR) is a common pediatric condition due to a developmental defect in the ureterovesical junction. The prevalence of VUR among individuals with connective tissue disorders, as well as the importance of the ureter and bladder wall musculature for the anti-reflux mechanism, suggest that defects in the extracellular matrix (ECM) within the ureterovesical junction may result in VUR. This review will discuss the function of the smooth muscle and its supporting ECM microenvironment with respect to VUR, and explore the association of VUR with mutations in ECM-related genes.

Generalized joint hypermobility and voiding dysfunction in children: is there any relationship?

Voiding dysfunction is a common entity in pediatric urology. It is believed to have a multifactorial etiology. The aim of this study was to investigate whether there is an increased prevalence of generalized joint hypermobility (GJH) in children with voiding dysfunction compared to normal children. Moreover, the prevalence of voiding complaints in patients with and without GJH was assessed. A total of 226 children--aged 5 to 14 years--including 113 patients diagnosed with voiding dysfunction and 113 sex/age/body mass index-matched normal children were recruited. GJH was evaluated in both groups using the Beighton score (4 or more= hypermobile). In the patient’s group, GJH was significantly more frequent than in controls: 51/113 (45 %) versus 19/113 (17 %) (P=0.001). In addition, in both groups, GJH was more prominent in girls than boys (P<0.05). Urinary tract infection was the most frequent features in children with voiding dysfunction (64 %). In the subgroup of positive GJH, urinary tract infection remained the most common manifestation among the girls (P=0.003), while constipation was the most prevalent manifestation among the boys (P=0.001).

CONCLUSION

Our findings suggest that children with voiding dysfunction have significantly higher prevalence of GJH compared to normal children. Further studies are needed to determine the cause and effect of these two common presentations and will help to develop a multidisciplinary approach in understanding and management of voiding dysfunction in children.

TNXB mutations can cause vesicoureteral reflux

Primary vesicoureteral reflux (VUR) is the most common congenital anomaly of the kidney and the urinary tract, and it is a major risk factor for pyelonephritic scarring and CKD in children. Although twin studies support the heritability of VUR, specific genetic causes remain elusive. We performed a sequential genome-wide linkage study and whole-exome sequencing in a family with hereditary VUR. We obtained a significant multipoint parametric logarithm of odds score of 3.3 on chromosome 6p, and whole-exome sequencing identified a deleterious heterozygous mutation (T3257I) in the gene encoding tenascin XB (TNXB in 6p21.3). This mutation segregated with disease in the affected family as well as with a pathogenic G1331R change in another family. Fibroblast cell lines carrying the T3257I mutation exhibited a reduction in both cell motility and phosphorylated focal adhesion kinase expression, suggesting a defect in the focal adhesions that link the cell cytoplasm to the extracellular matrix. Immunohistochemical studies revealed that the human uroepithelial lining of the ureterovesical junction expresses TNXB, suggesting that TNXB may be important for generating tensile forces that close the ureterovesical junction during voiding. Taken together, these results suggest that mutations in TNXB can cause hereditary VUR.