The objective of this study is to evaluate the safety of long-term treatment with Kuvan.

The PKUDOS program is a voluntary, multicenter, strictly observational program for patients with PKU who have either received Kuvan therapy, or currently receive Kuvan, or intend to begin receiving Kuvan therapy within 90 days of entering the registry.

PKUDOS Registry

Inclusion Criteria:

• Patient has confirmed diagnosis of PKU with hyperphenylalaninemia documented by a Phenylalanine level of greater than or equal to 360 umol/L (6 mg/dL)
• Patient has previously received Kuvan
• Patient is currently receiving Kuvan
• Patient intends to receive Kuvan therapy within 90 days of enrollment into the registry
• The Patient is being followed at a PKUDOS participating center
• Willing and able to provide written authorization or, if under the age of 18 years, provide written assent (if required) and written patient authorization by a parent or legal guardian
• Willing to provide personal health information

Exclusion Criteria:

• Patients are not eligible to participate in PKUDOS if they are participating in a BioMarin-sponsored clinical study of Kuvan
• Patients not previously treated with Kuvan and patients that are unwilling to begin Kuvan therapy within 90 days of entry into the registry

PKU MOMS Subregistry

Inclusion Criteria:

• Willing to enroll in (or are already enrolled in) PKUDOS
• Agree to follow the standard of care for pregnant women with PKU in the United States (NIH, 200, NIH Consensus Statement)
• Agree to be followed by a hospital or PKU clinic offering the standard of care for maternal PKU
• Are within 10 weeks of their last menstrual period

Exclusion Criteria:

• Patients who have not adhered to the standard of care for pregnant women with PKU in the United States are not eligible to participate in PKU MOMS

Diagnosis of Phenylketonuria with hyperphenylalaninemia