Methylmalonic Aciduria and/or Homocystinuria via the CD320 Gene

Individuals with elevated methylmalonic acid and no identified defects in other genes known to cause methylmalonic aciduria are good candidates for this test, particularly if they also have elevated C3-acylcarnitine levels, and possibly elevated homocysteine levels. Family members of patients who have known pathogenic CD320 variants are candidates. We will also sequence the CD320 gene to determine carrier status.