Bilateral:the kidneys are not founded, ureters are missing, the bladder is insufficiently developed (hypoplastic) and empty. Amniotic fluid is absent. Bilateral renal agenesis is not compatible with survival. The affected newborn dies several hours after birth of respiratory failure due to pulmonary hypoplasia. The incidence is 1 : 6000.
Most cases of bilateral renal agensis are sporadic. The minority of bilateral renal agenesis, and also bilateral dysplasia and combination of agenesis and dysplasia cases are familial, transimitted as an autosomal dominant trait (hereditary renal adysplasia or agenesis/dysplasia syndrom). The sydnrom has an incomplete penetrance and variable expression. There is an increas incidence of subtle genitourinary anomalies (solitary kidney, ureter duplex, uterine anomalies) among the family members of the proband. In suspicion of familial occurence the family members must be thoroughly examined even if asymptomatic.
Unilateral: rather common (1 : 1000) and has no serious consequences.
Right kidney agenesis, multicystic dysplasia of the left kidney, 23-week fetus: Agenesis of the right kidney, multicystic dysplasia of the left kidney, Macro, autopsy (72135)
Renal agenesis, discoid adrenal, 23-week fetus: Agenesis of the kidney, discoid adrenal, Macro, autopsy (72136)
Agenesis of both kidneys: Bilateral agenesis of the kidneys, Macro, autopsy (73266)
Unilateral agenesis of one kidney in a newborn, accidental autoptic finding: Unilateral agenesis of the kidney, Macro, autopsy (73965)