Name: Myeloperoxidase deficiency | Acronym: MPOD
Alt. names:

Gene: MPO | MOI: Autosomal recessive | Mechanism of action:

No. of cases in DB: 0 | First reported in: 1994

Last updated on: 2023-02-28 16:41:18 by Andrés Caballero-Oteyza

OMIM: 254600

Orphanet: -

MONDO: -

DOID: -

ClinGen:

It is characterized by decreased myeloperoxidase activity in neutrophils and monocytes. This is considered one of the most common inherited phagocyte defects with estimated prevalence of one in several thousand (PMID: 6267975). In the absence of MPO, auxiliary mechanisms protect most MPO-deficient hosts from clinically significant sequelae, except for some persons with diabetes mellitus who may suffer severe candidal disease. Measurement of bulk peroxidase activity in leukocytes may not accurately detect MPO deficiency, which can be masked by the normal activity of eosinophil peroxidase. It has also been noted that MPO deficiency may lead to artefactual pseudoneutropenia with the use of automated blood cell counters. Those that identify different types of leukocytes based on mean peroxidase index (MPXI) in addition to size and staining properties may incorrectly count MPO-deficient neutrophils as monocytes with lower MPXI values, potentially leading to an erroneous diagnosis of severe neutropenia. Thus, manual differential counting is recommended for confirmation in the setting of low neutrophil count with elevated monocyte count.

Many individuals do not show obvious clinical sequelae, but increased candiasis and incidence of severe infections has been reported in some individuals, and awareness may allow prompt recognition and treatment, which may reduce morbidity and mortality.