Vesicoureteral reflux (VUR) is one of the more common genetic disorders characterized by regurgitation of urine from the bladder to the kidney. The phenotype is associated with shortness of the sub-mucosal segment of the urethra due to congenital lateral ectopia of the ureteric orifice. Vesicoureteric reflux may be an isolated anomaly or associated with other congenital anomalies such as posterior urethral valves or complete duplication of the urinary tract.
Family studies suggest different modes of inheritance of vesicoureteric reflux, including a dominant single gene and polygenic inheritance. Genome-wide search has identified a 20-cM locus on chromosome 1 that is highly suggestive of linkage in VUR1 patients.
Zaki et al. (2003) determined the frequency of vesicoureteral reflux and associated renal changes in a group of Arab Kuwaiti children with their first documented febrile UTI. Zaki et al. (2000) performed a six-year retrospective case review of all children consecutively admitted to two regional hospitals in Kuwait that represent the only referral centers for children with UTI in their respective catchment area. One hundred and seventy-four children (38 males and 136 females) fulfilled the study criteria and were divided into three age groups (<1 year, 1-5 years, and >5 years). Patients in each group had both micturating cystourethrography (MCUG) and 99m-Tc-dimercaptosuccinic acid (DMSA) renal scan after diagnosis. VUR was detected in 39 children (22%). Two-thirds of cases had mild reflux (grade I and II). Females (n=32) had more reflux than males (n=7; 24% vs. 18%). Zaki et al. (2000) concluded that the frequency of VUR in Arab Kuwaiti children with febrile UTI is midway between Caucasian and other racial groups.
Al-Eisa et al. (2004) conducted a retrospective study of all children less than 16 years of age with end-stage renal disease treated in the pediatric nephrology unit in Kuwait over a period of 8 years (January 1995 to December 2002). Of the 48 children boys comprises 52% and the overall mean age at institution of dialysis was 94.4 months. Causes of renal disease included congenital structural anomalies in 52%, including obstructive uropathy in 16.6%, vesicoureteric reflux in 16.6%, and renal dysplasia/hypoplasia in 18.7%. Hereditary nephropathy was diagnosed in 35.4%. The mortality rate in the dialyzed group was 16%. Twenty-four patients received kidney transplants from, cadaveric donors in 19 cases. Al-Eisa et al. (2004) indicated that genetic factors contributed to the high incidence of end-stage renal disease, which is most likely due to the common practice of consanguineous marriages in the country.
In year 2000, Al-Gazali et al. reported four cases from an extended and highly inbred Arab family from Oman with autosomal dominant inheritance of a syndrome characterized by a variable combination of optic nerve colobomas, renal abnormalities, vesicoureteral reflux, lax joints and arthrogryposis multiplex. The four studied cases represented the 27-year-old father and three male children. Apart from the arthrogryposis multiplex which has not been described in the papillorenal syndrome, the features of the syndrome in this family are very similar to the papillorenal syndrome. However, sequencing of all 12 exons of PAX2 gene revealed no mutation in this family. Hence, the disorder in this family is likely to represent a new syndrome with features overlapping with the papillorenal syndrome.
Al Mohrij et al. (1996) analyzed the hospital records of patients with a diagnosis of VUR at a public hospital in Riyadh in a 10-year period (1983-1993) to study the etiology, pathology, management and outcome of this condition in this Saudi hospital. Data of 24 patients diagnosed with VUR in this period were analyzed. These 24 patients constituted 5.6% of all pediatric urological admissions in this period. The mean age at admission was 36.5 months, and the male:female ratio was 2.5:1. The most common presentation was Urinary Tract Infection followed by hydronephrosis diagnosed in utero. Two patients had severe hypertension, while two patients were asymptomatic. These latter patients were diagnosed incidentally by abdominal sonography for a non-renal indication. Of the 31 urine cultures available, E. coli grew in 21 cultures. The second most common organism was K. pneumonia. Interestingly, of the patients whose initial presentation was not UTI, almost 30% had positive urine cultures. Corrective surgery was required in only one of the patients with moderate VUR. More than 70% of the severe cases required reimplantation surgery. Al Mohrij et al. (1996) concluded that VUR was a common pediatric problem in early childhood. However, Abdurrahman (1997) commented that the data provided by Al Mohrij et al. (1996) was inadequate, and that 24 cases of VUR in 10 years could not be considered as a large number.
In year 2000, Habib et al. reported a 4-year-old boy from Saudi Arabia with an established diagnosis of Fanconi anemia. Ultrasonography and a renal nuclide scan showed a solitary kidney on the left side a micturating cystourethrogram showed gross vesicoureteral reflux. The findings observed in the patient are consistent with a diagnosis of solitary crossed renal ectopia (SCRE). In addition, the patient had hypospadias and unilateral undescended testis with absent vas deferens.
Ayadi et al. (2000) reported 100 cases of primary vesicoureteral reflux which occurred over a 7-year period in Tunisia. Patient age at presentation ranged from 1 month to 13 years, with a mean age of 3 years and 5 months. Overall, a higher rate of reflux was observed in the female population (63%) which was particularly evident after the age of 3 years, but with a male predominance during the first 12 months of life. In the majority of cases, the diagnosis of VUR was made following diagnosis and investigation of urinary infection (UI). A high level of UI was the most frequent sign of VUR (87% of cases), while in 6% of cases this disorder was diagnosed during the investigation of an uropathy which was found to be complex in all subjects. Ayadi et al. (2000) concluded that vesicoureteral reflux is a fairly common disorder in Tunisia.
Abou-Chaaban et al. (1997) studied the pattern of pediatric renal diseases among children in the Dubai Emirate during the period from 1991 to 1996. In this period, a total of 712 pediatric patients, including 230 nationals of the United Arab Emirates, were seen with various renal problems. Among congenital renal anomalies, vesicoureteric reflux was the commonest lesion seen in 32 patients of whom 22 had bilateral reflux.
[Abou-Chaaban M, Al Murbatty B, Abdul Majid M. Spectrum of pediatric renal diseases in Dubai. Saudi J Kidney Dis Transplant. 1997; 8(3):310-3.]