LONG-PCR OF THE ANP GENE AND PCR-SSCP ANALYSIS OF THE PROXIMAL PROMOTER REGION OF THE ANP GENE IN PATIENTS WITH ALDOSTERONE-PRODUCING ADENOMA

Previous studies have shown a significant association between allelic frequencies at the ANP gene locus and aldosterone responsiveness to an giotensin in aldosterone-producing adenoma (APA). We searched for any gross insertions or deletions in the ANP gene in APA and any associati ons between allelic frequencies at the Hpa Il and Sea I RFLP sites wit hin the ANP gene and angiotensin-responsive and unresponsive APA and n ormal subjects. We also searched for possible point mutations in the p romoter region of the ANP gene (-595 to transcription start site) in p eripheral blood and tumor DNA from 59 patients with APA and in periphe ral blood DNA from 39 normal subjects by polymerase chain reaction and single strand conformation polymorphism (PCR-SSGP) analysis. No large alterations in the ANP gene were observed, and no difference in allel ic frequencies at the RFLP sites were seen between the two tumor subty pes, angiotensin-responsive and angiotensin-unresponsive APA, or betwe en the APA group and normal subjects. SSCP analysis, however, did reve al mutations in the promoter region of the ANP gene (-375 to -595) in both peripheral blood and tumor DNA from 8 of 59 (14%) patients with A PA, compared with only one of 39 normal controls (2.6%). This study su ggests that alterations in the proximal promoter region of the ANP gen e in APA may be important in the regulation of ANP transcription and m ay be involved in the underlying pathophysiology of aldosterone-produc ing adenoma in at least some patients. (C) 1995 Academic Press, Inc.