<unk>  or Wyburn mason's syndrome or Retinoencephalofacial angiomatosis is a rare arteriovenous malformation (AVMs) condition. The  special name for wyburn mason's syndrome is called congenital retinocephalofacial vascular malformation syndrome" ("CRC syndrome"). In The United States of America in order to categorise a condition as a rare disease it should affect fewer than 200,000 people. Rare diseases also called as orphan diseases. Orphan Drug Act was passed on 1983 by congress for the rare diseases. Today an average of 25-30 million americans have been reported with rare diseases. The number of people with individual rare disease may be less but overall the number of people with rare diseases are large in number.
Bonnet-Dechaume-Blanc syndrome
Favre-Racouchot syndrome
Young–Simpson syndrome
Boyd-Stearns syndrome
Feigenbaum-Bergeron-Richardson syndrome
Weinstein Kliman Scully syndrome
Kearns–Sayre syndrome
Grisel's syndrome