A genetic test for RET, Von Hippel-Lindau (VHL), Neurofibromatosis type 1 (NF1), and of the genes coding for the different subunits of the succinate dehydrogenase (hereditary paraganglioma syndromes) is suggested in familial PCC to obtain a precocious diagnosis. The gene discussed is RET; the disease is neurofibromatosis type 1.