Bilateral multicystic renal dysplasia with Potter sequence.

I have read with interest the case report “Bilateral multicystic renal dysplasia with Potter sequence. A case with penile agenesis” by Dursun et al.1 The authors stated that the case “provides most symptoms of bilateral multicystic hereditary renal adysplasia (HRA)”. Although most cases of renal adysplasia (agenesis/ dysplasia) are sporadic, some cases are inherited. Hereditary renal adysplasia is probably inherited as an autosomal dominant condition as the authors stated. Therefore, when renal adysplasia is diagnosed, careful screening (renal ultrasound) of the parents, sibling, subsequent pregnancies, and other relatives are important for the purpose of accurate genetic counseling,2 as this anomaly can be asymptomatic. This was not performed in this family, and therefore one cannot state that this stillborn had an inherited disease. Although this child had a bilateral involvement and was a stillborn, this does not necessarily mean that affected family members should have a bilateral involvement and therefore will be symptomatic. Affected relatives of a proband with bilateral disease may have a unilateral involvement as this anomaly has variable expression,3 which supports the importance of screening in this family as the presence of a single normal kidney needs special precautions. Furthermore, the authors stated: “the penile agenesis was first reported and the consanguinity in the parents might further delineate the bilateral multicystic HRA”. This statement may not be accurate as appropriate family screening was not performed and since it is known that the most usual mode of inheritance of this disease is through an autosomal dominant gene, which is not affected by consanguinity. The presence of consanguinity may be a coincidence. Moreover, absence of this anomaly in the parents does not rule out an autosomal dominant inheritance2 as the gene may have incomplete penetrance; hence, aunts, uncles, and grandparents may have to be screened. Penile agenesis is not a new association with multicystic dysplastic kidneys as it was implied; an earlier report documented a similar association.4