Natural History Study of Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency (ACAPPELLA)

The purpose of the study is to characterize the clinical course of homocystinuria in pediatric and adult patients aged 1 to 65 years under current clinical management practices

Inclusion Criteria:

* Patients who are clinically diagnosed with homocystinuria
* Male/female patients aged 1 to 65 years
* Patients who consented and/or assented
* Patients who are willing and able to comply with all study-related procedures.

Exclusion Criteria:

* Medically significant postnatal complications or congenital anomalies that are not associated with homocystinuria
* Received any experimental therapy for homocystinuria during the 6 months prior to enrollment or expected to receive any such therapy during duration of the study