Hematologic features and clinical course of an infant with Pearson syndrome caused by a novel deletion of mitochondrial DNA.
OBJECTIVE
Pearson bone marrow-pancreas syndrome (PS) is a rare, usually fatal mitochondrial disorder involving the hematopoietic system in early infancy. Due to the diversity of clinical symptoms, the diagnosis can be difficult. The authors describe a boy with severe hypoplastic anemia in whom extensive clinical, biochemical, and morphologic findings led to the diagnosis of PS, and molecular analysis revealed a novel deletion of mitochondrial DNA from nucleotide position 10.371 to 14.607.


METHODS
The patient is a 2-year-old boy who presented at age 5 months with hypoplastic macrocytic anemia. His first months of life and the family history were uneventful. Extensive pretransfusion evaluations did not reveal a metabolic, infectious, or hematologic-neoplastic etiology, and he had no evidence of exocrine pancreatic insufficiency. However, a second bone marrow aspirate at age 7 months showed a reduced cell number, vacuolated erythroblasts and myeloblasts, and ringed sideroblasts, so PS was suspected.


RESULTS
Additional molecular analysis from the boy's blood leukocytes revealed a deletion of mitochondrial DNA from nucleotide position 10.371 to 14.607, which was absent in his mother's blood cells, consistent with a sporadic mutation as commonly seen in PS. The muscle histology and the respiratory chain enzymes were normal.


CONCLUSIONS
Mitochondriopathies should be considered in children with persistent non-neuromuscular symptoms such as unexplained refractory anemia. Due to the often-fatal course of PS, the rapid detection of mitochondrial DNA deletions is imperative for diagnosis and family counseling.
Knerr
Ina
I
Department of Pediatrics, University of Erlangen-Nuremberg, Germany. ina.knerr@kinder.imed.uni-erlangen.de
Metzler
Markus
M
Niemeyer
Charlotte Marie
CM
Holter
Wolfgang
W
Gerecke
Anja
A
Baumann
Irith
I
Trollmann
Regina
R
Repp
Reinald
R
D000748:Anemia, Macrocytic / Q000235:genetics / Q000473:pathology; D001855:Bone Marrow Diseases / Q000235:genetics / Q000473:pathology; D001856:Bone Marrow Examination; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D017353:Gene Deletion; D006801:Humans; D008297:Male; D028361:Mitochondrial Diseases / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D010182:Pancreatic Diseases / Q000235:genetics / Q000473:pathology; D013577:Syndrome
D004272:DNA, Mitochondrial