A negative test result generally indicates that the test subject does not carry the genetic variants in question, but it does not entirely exclude the possibility of developing such disease. Uncertainty exists in all results, be it positive or negative, and its magnitude depends on various factors, including the complexity of the genetic disease, the testing technology adopted, the stringency of the testing procedures and so on. If genetic testing is accompanied by counselling and explanation on the results by healthcare professionals, you can gain a better understanding of the results and its potential impact.