TY - JOUR
T1 - A Case of Reversible Infantile Respiratory Chain Deficiency Presenting With Hypotonia, Hyperammonemia, and Failure to Thrive
AU - Guerrero, Jessenia C.
AU - Pedro, Helio
AU - Parisotto, Sarah
AU - Heller, Debra
AU - Baisre-de Leon, Ada
N1 - Publisher Copyright:
© 2019, Society for Pediatric Pathology All rights reserved.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Reversible infantile respiratory chain deficiency, previously termed reversible infantile cytochrome c oxidase (COX) deficiency myopathy, is a rare mitochondrial disorder that is characterized by severe hypotonia and generalized muscle weakness in infancy that is associated with lactic acidosis. Affected infants will spontaneously recover, if they survive the first months of life. Here, we present the case of a 4-week-old girl who initially presented with hyperammonemia, hypotonia, and failure to thrive, for which she was referred for genetic evaluation. After several tests, a distinct genetic syndrome could not be identified and she continued to deteriorate. A muscle biopsy was performed and demonstrated severe mitochondrial myopathy with abundant COX-negative fibers. Ultrastructural abnormalities of the mitochondria, diagnostic of mitochondrial myopathy, were identified on electron microscopy. Molecular studies revealed the classic homoplasmic disease causing mutation, m.14674 T>C in the MT-TE gene, associated with reversible COX deficiency. Although hyperammonemia is an unusual presentation for mitochondrial myopathies, specifically reversible infantile respiratory chain deficiency, it should be included in the list of possible presenting symptoms for this condition.
AB - Reversible infantile respiratory chain deficiency, previously termed reversible infantile cytochrome c oxidase (COX) deficiency myopathy, is a rare mitochondrial disorder that is characterized by severe hypotonia and generalized muscle weakness in infancy that is associated with lactic acidosis. Affected infants will spontaneously recover, if they survive the first months of life. Here, we present the case of a 4-week-old girl who initially presented with hyperammonemia, hypotonia, and failure to thrive, for which she was referred for genetic evaluation. After several tests, a distinct genetic syndrome could not be identified and she continued to deteriorate. A muscle biopsy was performed and demonstrated severe mitochondrial myopathy with abundant COX-negative fibers. Ultrastructural abnormalities of the mitochondria, diagnostic of mitochondrial myopathy, were identified on electron microscopy. Molecular studies revealed the classic homoplasmic disease causing mutation, m.14674 T>C in the MT-TE gene, associated with reversible COX deficiency. Although hyperammonemia is an unusual presentation for mitochondrial myopathies, specifically reversible infantile respiratory chain deficiency, it should be included in the list of possible presenting symptoms for this condition.
KW - cytochrome c oxidase deficiency
KW - failure to thrive
KW - hyperammonemia
KW - mitochondrial myopathy
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U2 - 10.1177/1093526619860362
DO - 10.1177/1093526619860362
M3 - Article
C2 - 31333056
AN - SCOPUS:85070318047
SN - 1093-5266
VL - 22
SP - 590
EP - 593
JO - Pediatric and Developmental Pathology
JF - Pediatric and Developmental Pathology
IS - 6
ER -