Wolf–Hirschhorn syndrome (WHS) is a chromosomal disorder characterized by partial deletion of the short arm of chromosome 4. We describe a girl with a de novo unbalanced traslocation t(4;7)(p16.2;p22), associated with a mild version of a classical WHS phenotype. She did not present major urinary tract abnormalities but had parenchymal hyperechogenicity at renal ultrasound at the birth with normal renal scintigraphy. She had also a reduction of GFR with elevated levels of blood urea nitrogen and serum potassium until the age of 6 months. We followed the patient with periodic clinical examination and laboratory and radiological investigations and observed at the age of 5 years a normal renal ultrasound without parenchymal hyperechogenicity. © 2010 Wiley-Liss, Inc.