Sources:
- http://www.medicinenet.com/phenylketonuria/article.htm
- http://en.wikipedia.org/wiki/Phenylketonuria
- http://www.mayoclinic.com/health/phenylketonuria/DS00514/DSECTION=causes
- http://www.mayoclinic.com/health/phenylketonuria/DS00514/DSECTION=treatments-and-drugs
- http://www.yourgenesyourhealth.org/pku/cause.htm
- http://en.wikipedia.org/wiki/Phenylketonuria
- http://www.mayoclinic.com/health/phenylketonuria/DS00514/DSECTION=causes
- http://www.mayoclinic.com/health/phenylketonuria/DS00514/DSECTION=treatments-and-drugs
- http://www.yourgenesyourhealth.org/pku/cause.htm