Figure 2: Missense mutations in the MPO coding region. Representation of eight mutations found in patients with MPO deficiency indicates their presence on both the small and large subunits of MPO. These mutations may affect heme binding, as they occur near sites where heme interacts with MPO (indicated by*). They may also affect the final stages of processing where MPO forms a homo-dimer linked by a di-sulfide bond, which occurs in the large subunit (indicated by the triangle).