%0 Case Reports
%T A new mutation in the mitochondrial tRNAPro gene associated with early-onset neuromuscular phenotype and ragged-red fibers.
%A Morel G
%A Bannwarth S
%A Chaussenot A
%A Cano A
%A Fragaki K
%A Ait-El-Mkadem S
%A Rouzier C
%A De Paula AM
%A Chabrol B
%A Paquis-Flucklinger V
%J Neuromuscul Disord
%V 26
%N 12
%D Dec 2016
%M 27816331
%F 3.538
%R 10.1016/j.nmd.2016.09.012
%X An 11-year-old boy with psychomotor delay, exercise intolerance, ptosis and growth delay had a muscle biopsy showing typical mitochondrial alterations (60% of ragged-red fibers and 90% of cytochrome-c oxidase-deficient fibers). Next-generation sequencing revealed a novel heteroplasmic mutation (m.15958A>T) in the MTTP gene that encodes tRNAPro. The mutation was not present in the accessible non-muscle tissues of the patient's asymptomatic mother. Mutations in the rarely affected MTTP gene are responsible for different clinical presentations. We report the third early-onset case associated with a mutation in this gene. The severity of myopathy is likely related to the high mutation rate (96%) found in the patient's muscle. The clinical heterogeneity associated with MTTP mutations illustrates the value of the next-generation sequencing in routine diagnosis of mitochondrial diseases.