Monosomy 9p (also known as Alfi's Syndrome or simply 9P-) is a rare chromosomal disorder in which there is deletion (monosomy) of a portion of chromosome 9. Symptoms include microgenitalia, mental retardation with microcephaly and dysmorphic features. The disease was described in 1985 when Saint John, New Brunswick resident Stefan Guimond was diagnosed. Because of his cooperation with doctors, there has been significant advances in the management of this syndrome and the likelihood of surviving has risen to 74% from 36%. Stefan did not survive, but a statue was erected at the Saint John Regional Hospital on October 7, 1989 in his memory.
The location has recently been narrowed to 9p22.2-p23.