Renal agenesis can develop as a component of a syndrome or as an isolated anomaly [1]. This congenital disorder is classified as unilateral or bilateral.

Unilateral renal agenesis

Renal agenesis is commonly unilateral with a predilection for males [2]. Individuals with only one kidney will likely remain asymptomatic [3] and achieve a normal life expectancy. Typically, the sole kidney enlarges to compensate for the absent kidney. This disorder is usually discovered incidentally.

Among the various urologic pathologies that are observed in patients with unilateral renal agenesis, contralateral vesicoureteral reflux is most frequent [4].

Bilateral renal agenesis

Babies with this type of renal agenesis will die in utero or within a few hours of life due to immature lungs and consequently respiratory failure [5]. These patients lack the complete development of kidneys and ureters and hence manifest with the interrelated complications of pulmonary hypoplasia and oligohydramnios.

Regarding the clinical presentation, patients exhibit the Potter sequence, which is characterized by extrarenal features such as wide-set eyes, epicanthal folds, flat nose, large low-set ears with absent cartilage, receding chin, and limb defects [6] [7]. Furthermore, there may be other systems that are involved in Potter syndrome. Among these are cardiac malformations [8] and abnormalities of the gastrointestinal [5] and genitourinary [9] tracts.

Pregnancy complications

A fetus with renal agenesis is at risk for intrauterine growth retardation (IUGR), breech presentation, and premature delivery.

• Periorbital Edema

  Homozygotes for this allele (hereafter, greb1l mutants) were readily recognized at 3 dpf by periorbital edema and pericardial effusions, consistent with a defect in ion and fluid homeostasis (16 embryos in a clutch of 109 embryos showed this phenotype [doi.org]

• Skin Lesion

  Although renal agenesis, hemihypertrophy and hyperpigmented macular skin lesions (skin naevuses) may be incidental findings, together they may form a variant of Klippel-Trenaunay-Weber syndrome, as in our case. [ncbi.nlm.nih.gov]

• Vaginal Bleeding

  A 27 year old female presented with two months history of continuous vaginal bleeding. [ncbi.nlm.nih.gov]

Routine widespread use of prenatal ultrasonography improves detection of renal agenesis and other conditions associated with it. Findings are likely to include oligohydramnios, absent kidney(s), absent bladder (particularly in bilateral renal agenesis), hypertrophy of the solitary kidney secondary to compensation (in a fetus with unilateral renal agenesis), and other abnormalities. Moreover, color doppler ultrasonography demonstrates the presence of the renal artery(ies) [10]. The presence of an ectopic kidney should be considered and ruled out [11].

Prenatal magnetic resonance imaging (MRI) may be useful for confirmation of bilateral renal agenesis when ultrasonography is not definitive [12].

A special procedure known as amnioinfusion can be used to evaluate low levels of amniotic fluid [13].

Postnatal tests

Neonatal laboratory studies include serum electrolyte measurements, renal function tests, complete blood count (CBC), and urinalysis. Additionally, levels of urine sodium, creatinine,and osmolality may be warranted.

Various imaging modalities such as abdominal ultrasonography, MRI, and computed tomography (CT) can be performed on the neonate to confirm the congenital defects identified prenatally. Procedures such as voiding cystourethrography and nuclear renal scanning are used to evaluate the genitourinary tract. Additionally, a chest x-ray is used to assess pulmonary hypoplasia.

Genetic tests

All pregnant women carrying fetus(es) with congenital defects should undergo genetic counseling and possibly testing. The family history is a significant component of the workup.

Very importantly, chromosomal analysis for various trisomies and conditions are indicated in infants with a clinical picture suggestive of a genetic disorder [1].

• Small Kidney

  MATERIAL AND METHODS: In this single center, cross-sectional study, a total of 55 patients (39 (% 70.9) with unilateral small kidney and 16 (%29.1) with renal agenesis) were included. The median age was 35 (21-50) years. [ncbi.nlm.nih.gov]

  A small kidney may produce arterial hypertension or chronic urinary tract infection or even possibly result in a renal neoplasm. Two other points should be remembered in assisting one in making the correct diagnosis. [fetalsono.com]

• Unilateral Small Kidney

  MATERIAL AND METHODS: In this single center, cross-sectional study, a total of 55 patients (39 (% 70.9) with unilateral small kidney and 16 (%29.1) with renal agenesis) were included. The median age was 35 (21-50) years. [ncbi.nlm.nih.gov]

• Pericardial Effusion

  Homozygotes for this allele (hereafter, greb1l mutants) were readily recognized at 3 dpf by periorbital edema and pericardial effusions, consistent with a defect in ion and fluid homeostasis (16 embryos in a clutch of 109 embryos showed this phenotype [doi.org]

This condition should be considered to prevent misdiagnosis or suboptimal treatment. [ncbi.nlm.nih.gov]

“It’s only an appropriate treatment for fetuses with no kidneys, or for those with non-functioning kidneys, who don’t have other genetic or serious anomalies. We are not currently looking at this treatment for low fluid of other etiologies.” [hopkinsmedicine.org]

Dialysis is a treatment that filters and purifies the blood using a machine. This helps keep your body in balance when the kidneys can’t do their job. Factors such as lung development and overall health determine the success of this treatment. [healthline.com]

The prognosis of individuals with isolated URA is good. There are reports of hypertension and renal insufficiency in long-term studies of patients with a single kidney, and lifetime follow-up is recommended. [ncbi.nlm.nih.gov]

Argueso LR, Ritchey ML, Boyle ET Jr, Milliner DS, Bergstralh EJ, Kramer SA (1992) Prognosis of children with solitary kidney after unilateral nephrectomy. J Urol (in press) Google Scholar 12. [link.springer.com]

What is the Prognosis of Bilateral Renal Agenesis? (Outcomes/Resolutions) The prognosis of Bilateral Renal Agenesis is very poor; neonatal deaths are unavoidable. [dovemed.com]

Prognosis In the absence of kidney injury or disease, the prognosis for unilateral renal agenesis is excellent. Individuals with unilateral renal agenesis usually lead normal, healthy lives. [encyclopedia.com]

Renal agenesis is a rare condition of unknown etiology frequently seen together with ipsilateral seminal vesicle and vas deferens anomalies because of common embryologic development. [ncbi.nlm.nih.gov]

An etiologic diagnosis of seizure and rational therapy requires cohesive analysis of all the clinical facets of the patient, even though some of them may appear unrelated. The present case aptly demonstrates this fact. [annalsofian.org]

The etiology of renal agenesis is suggested. In many instances there are anomalies of other parts of the body. In a few cases it is recognized that genetic factors are responsible. [pediatrics.aappublications.org]

Etiology of Potter's Syndrome: Recessive inheritance is likely, siblings of children with bilateral renal agenesis are also affected in 3.5%. [urology-textbook.com]

Epidemiology of Potter's syndrome: Incidence: 3–15/100.000 births for bilateral renal agenesis, 3–20/100.000 births for bilateral renal dysgenesia. In 75%, boys are affected. [urology-textbook.com]

This article reviews the embryology, epidemiology, etiology, clinical features and other malformations associated with congenital renal agenesis. [sjkdt.org]

Echandía, Associate Professor, Department of Pediatrics, Faculty of Health, Universidad del Valle, Master s in Epidemiology, for his collaboration in the initial protocol and questionnaire. [colombiamedica.univalle.edu.co]

[…] kidney、renal dysplasia）」「腎低形成（hypoplastic kidney、renal hypoplasia）」「腎無形成（renal agenesis）」「逆流性腎症（reflux nephropathy）」「水腎症（hydronephrosis）」「膀胱尿管逆流（vesicoureteric reflux）」「腎盂尿管移行部狭窄（pelviureteric junction obstruction）」「後部尿道弁（posterior urethral valves）」「疫学（epidemiology [natureasia.com]

Clinical-epidemiological analysis of a large consecutive series of malformates infants. Am J Med Genet A. 2008;1;146:15-25. 8. Granese R, Coco C, Jeanty P. [tmj.ro]

[…] at birth Lack of amniotic fluid (oligohydramnios) with BRA, causing complications such as impaired fetal lung development, thoracic compression, limb contractures, and other abnormalities BRA is always fatal Formerly called Potter's syndrome Overview-Pathophysiology [quizlet.com]

The pathophysiological mechanisms leading to total absence of kidney development thus remain largely elusive. [ncbi.nlm.nih.gov]

Pathophysiology Prior to 16 weeks' gestations, the amount of amniotic fluid is dependent on the transmembrane flow. After that, fetal urine production is the predominant mechanism that determines the amniotic fluid volume. [emedicine.medscape.com]

Unilateral renal agenesis cases complicated by associated such anomalies need definitive management and lifelong clinical monitoring to diagnose and prevent chronic kidney disease. [ncbi.nlm.nih.gov]

Case: We report a case of renal agenesis identified in a fetus in which serial amnioinfusions were employed to prevent pulmonary hypoplasia and compression effects. A total of ten amnioinfusions were performed between 17-33 weeks' gestation. [journals.lww.com]

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