PS-BPB06-9: PREVALENCE OF KCNJ5 MUTANT ALDOSTERONE-PRODUCING ADENOMAS AMONG MALAYSIAN PATIENTS WITH PRIMARY ALDOSTERONISM

Abstract

Objective: To verify the prevalence of KCNJ5 mutant aldosterone-producing adenomas (APAs) among primary aldosteronism (PA) patients from a tertiary center in Malaysia Design and method: A total of 80 adrenal samples from adrenalectomies performed between 2010 up to 2020 at Hospital Putrajaya, Malaysia were included in this study. Of the adrenals blocks received, DNA samples from 74 APAs identified by CYP11B2 immunohistochemistry (IHC) staining were sent for KCNJ5 mutation analysis. Gender, ethnicity and age at adrenalectomy were compared between genotypes. Data were statistical analyzed using the Fisher Exact test. Results: 28 of the 74 (37.8%) APAs had a KCNJ5 mutation. The most common KCNJ5 variant was G151R (50%), followed by L168R (39.3%) and T158A (10.7%). Of all the mutant APAs, 19/28 (67.9%) were from female PA patients whereas among controls 26/46 (56.5%) were females. No significant association between KCNJ5 mutation status and gender were found. The majority of mutant APAs were from Malay PA patients (n = 17), followed by Chinese PA patients (n = 11) which follows the whole cohort demography. Thus, ethnicity was not found to be significantly associated with KCNJ5 mutation status. In this cohort, no significant differences in age at of adrenalectomy by KCNJ5 mutation status was seen. Adrenalectomy procedure was performed most frequent between the age of 37–46 years old (n = 30), followed by 47–56 (n = 16), 26–35 (n = 12), 57–66 (n = 11) and 67–76 (n = 2); in 3 patients this information was not known. Conclusions: A similar prevalence of KCNJ5 mutant APAs as found in a previous study performed at the National University of Malaysia Medical Centre between 2000 and 2015 verifies the lower prevalence of KCNJ5 mutant APAs in Malaysian PA patients (37.8%) compared to that observed in other Oriental cohorts (up to 70%). Although, the majority of mutant APAs were from female PA patients (67.9%), no gender bias according to KCNJ5 mutation status was found as the majority of PA patients in this cohort were females (60.8%).