[MIM 557 000]

Incidence < 1.106. Mitochondrial cytopathy due to the deletion of part of the mitochondrial DNA. 

Clinically, the disease can present as

-        a refractory sideroblastic anemia in infants (onset at the median age of 5 months), associated with neutropenia and thrombocytopenia of varying intensity; it usually resolves spontaneously between 1 and 3 years of age (66 %)

-        an exocrine pancreatic dysfunction (27-62 %): delayed growth, vomiting, diarrhea

-        high blood levels of lactic acid and episodes of lactic acidosis; the lactate/pyruvate ratio is > 20

with gradual appearance of

-        hepatomegaly (30-70 %)

-        hypotonia of varying severity

-        a renal tubulopathy, which can lead to progressive kidney failure

-        ocular involvement: ptosis, retinitis pigmentosa, cataracts

-        various endocrine abnormalities: insulin-dependent diabetes, hypothyroidism, adrenal insufficiency

Death occurs before 3 years of age in 50 % of cases: infection, metabolic crisis, heart rhythm disorders.

Children who survive infancy often develop the Kearns-Sayre syndrome (see this term). Increased risk of malignant myelodysplastic syndrome.

Anesthetic implications:

total blood count, basal lactic acid levels, ECG and echocardiography. Anesthetic management of a mitochondrial cytopathy (see this term).

References:

-        Yoshimi A, Ishikawa K, Niemeyer C, Grünert SC.
Pearson syndrome: a multisystem mitochondrial disease with bone marrow failure.
Orphanet Journal of Rare Diseases 2022 ; 17:379

Updated: January 2023