Whats "non-afn amer glomerular filtration rate"?

Their GFR.: Glomerular filtration rate is a test that tells how well the kidneys are doing their job. That is, how well/how fast they clear out fluid from the blood stream, which has impurities in it. Non-african americans tend to have a different rate than the rest of the population, hence the designation in a blood test, since it is a more clear indication of how well their kidneys are doing.