Chronic kidney disease (CKD) is most common in older adults (age>60), affects both sexes equally, and is primarily due to diabetes and hypertension. Currently, a form of early onset CKD called "chronic kidney disease of uncertain etiology (CKDu)- ie, cause (or causes) are unknown, is becoming increasingly common worldwide. CKDu disproportionately affects males at younger ages and cannot be attributed to traditional risk factors. Individuals in agricultural regions are most affected by the disease. We study a subset of CKDu found on the Pacific coast of Central America called Mesoamerican nephropathy (MeN).