"The MaP Study": Mapping the Patient Journey in MMA and PA

Inclusion Criteria: MMA Only • Patient has a confirmed diagnosis of isolated MMA due to MUT deficiency (mut0 or mut-) based on the following criteria: * Elevated plasma/serum/DBS or urine methylmalonic acid levels * Presence of normal serum/plasma vitamin B12 and plasma homocysteine levels * Confirmed by molecular genetic testing. Genetic testing can be performed after the administration of informed consent if not available, however, molecular genetic results must be confirmed before the second study visit PA Only • Patient has a confirmed diagnosis of isolated PA based on the following criteria: * Elevated plasma/DBS/urine 2-MC and/or 3-HP * Elevated plasma/serum/DBS propionylcarnitine (C3) * Confirmed by genetic testing for mutations of the PCCA or PCCB genes. Genetic testing can be performed after the administration of informed consent if not available, however, molecular genetic results must be confirmed before the second study visit Both MMA and PA * Patient (and/or legally authorized representative as applicable to local regulations) is willing and able to comply with study-related assessments and activities * Patient or legally authorized representative is willing and able to provide informed consent and/or assent as mandated by local regulation Exclusion Criteria: * Estimated GFR \<30 mL/min/1.73m2 based on age appropriate equations or patients who undergo chronic dialysis * The patient is pregnant or lactating at the time of screening. (Note: Patients who become pregnant during the study may remain in the study) MMA Only * Patients diagnosed with isolated MMA cblA, cblB, or cblD enzymatic subtypes or methylmalonyl-CoA epimerase deficiency or combined MMA with homocystinuria PA Only * Patient has a confirmed diagnosis of multiple carboxylase deficiency