How Rare is FG Syndrome?
FG Syndrome was originally described as extremely rare in the 1970s. While it remains uncommonly known at the present time, some evidence points to the likelihood that it is actually much more common than originally described. Only future DNA testing will tell us for sure just how common FG Syndrome is, but many clinical geneticists, including Dr. Opitz who first described it as rare, now feel that it is quite common.
Opitz Kaveggia Syndrome (FGS1), the only form of FGS for which there is currently accessible DNA testing, does appear to be a relatively rare form of FGS.