Does a novel genetic variant, highly expressed in Samoans, explain their increased propensity to develop Chronic Kidney Disease? A pilot study.

Chronic Kidney Disease (CKD) continues to increase globally. In a New Zealand, a community based prevalence study, Pacific peoples had a 2.56 fold higher risk of CKD, controlling for diabetes. Likewise Pacific people (predominantly Samoan) in NZ with a family history of ESKD have an increased risk of nephropathy independent of diabetes, suggesting a genetic component. Recent studies have identified the CREBRF p.Arg457Gln gene variant prevalent among Samoans, which predisposes against obesity, yet protects against diabetes, yet fails to show any association with CKD. This cross sectional pilot study aimed to identify whether an association between the CREBRF p.Arg457Gln gene and early signs of kidney damage, as defined by proteinuria, as a way of identifying those individuals at potential risk for progressive CKD. 175 Samoans from a local church community in Upolu Samoa, were recruited for the study. They underwent screening for blood pressure, urine dipstick and point of care testing for urinary albumin creatinine ratio (UACR) serum creatinine and eGFR (CKD-EPI), and HbA1c. 20 were excluded due to newly identified diabetes (HbA1c >50mmol/mol) and/or serum creatinine >150 mmol/L. 141 blood samples were collected in the end for genetic analysis. 155 participants (83males) were included, whose ages ranged from 20 -50 years. 64% of females and 33% males were either severely obese or morbidly obese according to BMI. 26% had normal renal function with no urinary abnormalities. 35% had dipstick positive proteinuria and an elevated urinary ACR. 62% of males had evidence of an impaired eGFR, 48% had stage 2 CKD and 15% eGFR