Accumulation of allelic changes at chromosomes 7p, 18q, and 2 in parathyroid lesions of uremic patients

We examined by microsatellite allelotyping 69 hyperplastic lesions of the p arathyroid glands from 23 patients with refractory, uremic hyperparathyroid ism. Allelic changes, at least at one chromosomal arm, were found in 31 of the 69 lesions (43%). Alteration at a single chromosome was seen in 14 lesi ons and at two to four chromosomes in 11 lesions, and there were five to ei ght alterations in 5 nodules. Allelic imbalance occurred most frequently at chromosome 7p between the EGFR gene and locus D7S817 (16%), at 18q between loci D18S61 and D18S70 (14%), and at chromosome 2 between D2S380 and D2S13 91 (9%). X-inactivation study showed a monoclonal growth in 18 of 29 nodule s in females, and a loss of the Y chromosome was seen in 8 of the 39 nodule s obtained from males. Our results suggest that the uremic "hyperplastic" n odules have a molecular pathway distinct from those known for sporadic prim ary parathyroid adenomas.