PTH and primary hyperparathyroidism: Lower VDR and higher PTH mRNA levels were associated with primary hyperparathyroidism for minor allele homozygotes of rs1544410 and rs7975232, and major allele homozygotes of rs731236 polymorphism.[34] The level of PTH has been associated with renal failure for rs2228570 major allele homozygotes.[37]