New β‐ENaC Polymorphisms among Salt Sensitive and Salt Resistant Nigerian Subjects (LB718)

Document Type



Biomedical Sciences (East Africa)


The relationship between the β-T594M polymorphism of the epithelial sodium channel (ENaC) and hypertension remains equivocal. This study was designed to determine the occurence of the β-ENaC polymorphism among Nigerians as a first step towards determining its importance as a determinant of hypertension in this populace. Forty-seven normotensive (NT) and fifty-three age-matched hypertensive (HT) subjects earlier divided into salt sensitive (SS) and salt resistant (SR) subgroups were recruited for this study. Ethical approval (CM/COM/8/Vol.XXI) was granted by University of Lagos. Blood samples were dried on Whitman filter paper and stored at room temperature until analysed. DNA was isolated from the blood spots followed by ampification by polymerase chain reaction (PCR). The amplicons were thereafter sequenced for β-ENaC polymorphisms. Polymorphisms were recorded in 13% of the subjects. Five (5%) of the subjects were positive for the β-T594M polymorphism: 2 NT (both SS) and 3 HT (2 SS and 1 SR).Three new non-synonymous mutations were recorded among HT subjects: β-E632V and β-E636V respectively among two SS HT subjects while β-D638Y was recorded in an SR HT subject. A fourth new mutation β-L628Q was recorded in an SS NT subject. A synonymous polymorphysm, β-T577t was observed in three SS HT subjects and one SS NT subject. The non-synonymous mutations are likely to be important in the development of salt sensitive hypertension among this populace considering the prevalence (9/100) in such a modest number of subjects. It is of interest that the β-T594M and the β-D638Y were also recorded in SR subjects as this might question the relationship between ENaC and salt sensitivity.


This work was published before the author joined Aga Khan University.

Publication (Name of Journal)

Federation of American Societies for Experimental Biology