There are two types of polycystic kidney disease (PKD):
- Autosomal recessive polycystic kidney disease (ARPKD) (presents in childhood)
- Autosomal dominant PKD (ADPKD) (presents in adulthood, typically aged 30-50)
Genetics
Autosomal recessive polycystic kidney disease (ARPKD) is caused by a mutation of the polycystic kidney and hepatic disease 1 (PKHD1) gene on chromosome 6. This gene codes for fibrocystin, a receptor-like protein, which is thought to play an important role in the development and functioning of the renal tubules and bile ducts.
Features
ARPKD is often picked up on antenatal scans with oligohydramnios (reduced amniotic fluid volume due to low urine output).
Potter syndrome can result from oligohydramnios (ARPKD is not the only cause). It involves dysmorphic features:
- Underdeveloped ear cartilage
- Low set ears
- Flat nasal bridge
- Abnormalities of the skeleton
Oligohydramnios can lead to underdeveloped fetal lungs (pulmonary hypoplasia), resulting in respiratory failure shortly after birth. Additionally, large cystic kidneys take up space in the abdomen, making breathing more difficult.
Patients may require haemodialysis within days of birth.
Patients have various ongoing problems throughout life:
- Chronic kidney disease (end-stage renal failure often occurs before reaching adulthood)
- Hypertension
- Liver failure due to congenital liver fibrosis
- Portal hypertension leading to oesophageal varices
Prognosis
Survival depends on extensive interventions, both in the neonatal period and throughout life. Around a third will die in the neonatal period, usually due to respiratory disease. Around a third will survive to adulthood.
Last updated March 2025
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