# Philadelphia chromosome

> English word · Noun

## Definitions
1. Human chromosome 22, after it has, pathologically, traded some of its genetic material with chromosome 9; this often causes chronic myelogenous leukemia.

## Etymology
The abnormality was first discovered and described in 1959 by David Hungerford from the Institute for Cancer Research and Peter Nowell from the University of Pennsylvania School of Medicine. Both facilities are located in Philadelphia, Pennsylvania.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/philadelphia-chromosome