Genetic Diseases, Inborn. Genetic Diseases . Genetic Disorders . Hereditary Disease . Inborn Genetic Diseases . Single-Gene Defects . Defect, Single-Gene . Defects, Single-Gene . Disease, Genetic . Disease, Hereditary . Disease, Inborn Genetic . Diseases, Genetic . Diseases, Hereditary . Diseases, Inborn Genetic . Disorder, Genetic . Disorders, Genetic . Genetic Disease . Genetic Disease, Inborn . Genetic Disorder . Inborn Genetic Disease . Single Gene Defects . Single-Gene Defect . Hereditary Diseases . Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent's genome or they may be acquired in utero. . 1.00