he mechanism of multicystic dysplastic kidney is a result of an abnormal induction of metanephric mesenchyme. This could be a result of a formation difficulty of the mesonephric duct. Some mutations in genes associated with renal dysplasia (in syndromes)have been determined. The mutations in question occur at EYA1 or SIX1 genes ( branchio-oto-renal syndrome). The PAX2 gene is also thought to play a role in MCDK.