Early onset polycystic kidney disease: how early is early?

We report a case of a six-month-old infant with autosomal dominant polycystic kidney disease. He was a full term baby with an uneventful pre and postnatal period. He was delivered by uncomplicated vaginal delivery without forceps or fetal distress. His father was recently diagnosed with adult onset autosomal dominant polycystic kidney disease (APKD) with creatinine clearance around 25%-30%. The parents requested renal ultrasound of the baby to screen for APKD. It revealed normal sized and normal shaped kidneys, but with multiple bilateral cysts in the renal cortices, each measuring about 5 mm-7 mm in diameter. Subsequent DNA analysis showed presence of PKD1 gene, present on chromosome 16. His renal function was within normal range. The baby needs to be regularly followed-up for the most common complications of APKD, including hypertension and renal insufficiency.