ARPKD

• some cases of suspected autosomal recessive polycystic kidney disease (ARPKD) are detected in utero by the presence of enlarged kidneys and oligohydramnios.
• Most patients who have ARPKD present during the immediate postnatal period or early infancy.
• Because there is a wide spectrum of severity at birth, affected infants may exhibit various features, the most common of which is bilateral flank masses.
• Renal function may be normal or markedly reduced at birth.
• Other features observed in infants who have ARPKD include:
  • hepatic fibrosis
  • hypertension
  • a urinary concentrating defect.
• Some patients may have adequate renal function for many years; others may require immediate renal replacement therapy.
• Other signs suggestive of but not exclusive to ARPKD are
  • Potter facies (low-set ears, flattened face, micrognathia)
  • respiratory distress due to pulmonary hypoplasia
  • decreased glomerular filtration rate.
• Because many other conditions (eg, posterior urethral valves with severe bilateral hydronephrosis) may mimic ARPKD clinically, radiologic evaluation frequently is required to confirm the diagnosis.
• In patients who have  ARPKD, renal ultrasonography typically reveals bilateral renal enlargement, with increased echogenicity. Cysts usually are not visualized in the neonatal period.
• Intravenous pyelography also demonstrates bilateral renal enlargement as well as delayed excretion and medullary streaking. Computed tomography shows bilateral enlargement with opacification.
   
• Although patients who have ARPKD occasionally experience pyuria, urinary tract infections (UTIs) are rare. The presence of a UTI in an infant should prompt evaluation for other congenital renal malformations (eg, posterior urethral valves, vesicoureteral reflux). Urolithiasis is rare in the neonatal period and most likely presents with hematuria but kidneys of normal size.
   
• ADPKD: Cerebral aneurysms may be seen in patients who have autosomal dominant PKD (ADPKD), but rarely are they present in those who have ARPKD. Similarly, patients who have ADPKD exhibit cysts in other organs, including the pancreas and spleen, but these features are not seen in ARPKD.

References:
Holmes LB. Teratogen-induced limb defects. Am J Med Genet. 2002;112:297-303.
Abstract available online

Hoyme HE, Jones KL, Dixon SD, et al. Prenatal cocaine exposure and
fetal vascular disruption. Pediatrics. 1990;85:743-747.
Abstract available online

Jones KL. Recognizable patterns of malformations: limb defects as
major feature. In: Smithís Recognizable Patterns of Human
Malformation. 5th ed. Philadelphia, Pa: WB Saunders Co; 1997:300-325


 

ARPKD and congenital hepatic fibrosis