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Updated: Jun 23, 2026
A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene
Published on: April 1, 2019
Two novel cosegregating mutations in tRNAMet and COX III, in a patient with exercise intolerance and autoimmune
1Child Neurology and Psychiatry Unit, Institute of Child Health IRCCS, Burlo Garofolo, Via dell'Istria 65/1, 34137 Trieste, Italy.
Abstract:
We report a 12-year-old patient with growth retardation, exercise intolerance, lactic acidosis (increasing after exercise) and autoimmune polyendocrinopathy type 2. Muscle biopsy shows abundant COX-negative fibers, subsarcolemmal mitochondrial aggregates and markedly reduced activities of all respiratory chain complexes. Genetic analysis identified two new cosegregating mutations in Met-tRNA (m.4415A>G) and Cox III (m.9922A>C), located in highly conserved regions of MtDNA. Both the mutations are heteroplasmics in multiple patients' tissues. Single-muscle fiber analysis showed significantly higher levels of both the mutations in COX-negative than in normal fibers. In addition, a possible link between the mitochondrial dysfunction and the autoimmune disease is suggested.
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