Examples of two behaviors needed for a person with SCD or SCT to reduce the risk of having a child with SCD include [1] talking with one’s potential reproductive partner about sickle cell status and [2] seeking partners with Hb A. These behaviors, however, are not well-known or easy to accomplish for them or for any of the other 3 million Americans with one of the 10,000 other single-gene diseases (e.g., Huntington disease, Fragile X syndrome, cystic fibrosis, or muscular dystrophy) [13]. This evidence concerns the gene GSTM1 and Schnyder corneal dystrophy.