CDC73 Germline Mutation in a Family With Mixed Epithelial and Stromal Tumors

Objective To describe a family in which 3 members presented with mixed epithelial tumor of the kidney (MEST) and were found to possess a germline mutation in CDC73, a gene which is associated with hyperparathyroidism-jaw tumor syndrome (HPT-JT). Materials and Methods Blood and tumor DNA from three family members who presented with a primary diagnosis of MEST was subjected to targeted gene sequencing to identify potential genetic components. Results A germline start codon mutation (p.M1I) in CDC73 was identified in all 3 family members who presented with MEST and 2 tumors from 1 patient demonstrated somatic copy-neutral loss of heterozygosity. Patients presented with no evidence of hyperparathyroidism or jaw tumors, but both female patients had hysterectomies at an early age due to excessive bleeding and numerous fibroids, which is common in HPT-JT. A germline p.M1I mutation has been previously reported in a family with clinical features of HPT-JT. Conclusion Patients with MEST may be at risk for HPT-JT and CDC73 germline mutation testing of MEST patients should be considered.