Diseases and syndromes associated with unilateral renal agenesis in children

Abstract

The incidence of congenital malformations is increasing annually, with a single kidney developmental disorder accounting for 4–8% of urinary system malformations. If the contralateral organ is normal, agenesis of the kidney is not clinically apparent and is usually detected during a preventive examination of the child or during an examination for combined anomalies of the genitourinary and urinary system.This pathology occurs due to a disruption of the interstitial interaction between the ureteral bud and the metanephrogenic tissue from 4th to 8th gestation weeks. By this time, the mesonephral (Wolff) ducts are already fully formed, in contrast to the paramesonephral (Müllerian) ducts, which develop only by the 5th week of the intrauterine period, that is, in the period of high risk of malformations of the urinary system. Accordingly, anomalies of the female genital system are more common than those of the male one, with concomitant agenesis of the ipsilateral kidney. Diagnosis of unilateral agenesis of the kidney is possible when performing routine antenatal screening or conducting preventive examinations at decreed dates. In girls, the most common genital anomalies are true unicornuate uterus (65%), bicornuate uterus with one rudimentary horn (7.3%), atrophy of one fallopian tube and ovary, absence or hypoplasia of the vagina, and vaginal doubling. In boys with unilateral agenesis of the kidney, the seminal vesicles, prostate gland, and testicular appendage may be rudimentary or absent. Agenesis of the kidney is a component of such genetic syndromes as OHVIRA, Kallman, Zinner, and Mayer–Rokitansky–Küster–Hauser syndromes. It is also combined with other congenital anomalies of the kidney and urinary tract and extrarenal anomalies, including mainly malformations of the gastrointestinal tract, heart and musculoskeletal system. Consequently, children with this pathology should be fully screened to rule out associated malformations and anomalies.