More than 100 years ago, the dermatologists William Anderson1 and Johannes Fabry2 each independently reported a case of a male patient with numerous angiokeratomas (AKs) and other symptoms. Today called Anderson-Fabry disease or Fabry disease (FD), this panethnic disorder is the second most prevalent lysosomal storage disease in humans (Online Mendelian Inheritance in Man 301500). Although questioned recently,3 FD, an X chromosome–linked disorder, is considered to be inherited in a recessive fashion.