HNF1B and Abnormal renal morphology: Microdeletions show a greater effect size than microduplications, which is consistent with other shared phenotypes.3 6 Heterozygous variants in HNF1B are one of the most common monogenic causes of developmental kidney disease.33 Rare cases of renal malformations have been reported in microduplication carriers,34 but systematic imaging of affected individuals has not been published so far, to the best of our knowledge.