CDC73 and familial isolated hyperparathyroidism: In one large study [16], large gene deletions represented 35% of all the CDC73 genetic lesions identified, regardless of phenotypic presentation (sporadic parathyroid carcinoma, FIHP or HPT-JT), suggesting a possible underestimation of the presence of such genomic rearrangements at the CDC73 locus in the pathogenicity of the syndrome.