A 16-year-old phenotypic female is evaluated for primary amenorrhea. She is at the 10th percentile for height and has a broad chest with widely spaced nipples and mild bilateral neck webbing. Blood pressure is 148/92 mm Hg. Pelvic ultrasound shows streak ovaries. Karyotype is 45,X. Renal ultrasonography demonstrates a single midline renal mass located low in the abdomen. Which of the following embryologic events most likely explains the renal finding in this patient?