Mild trifunctional protein deficiency is associated with progressive neuropathy and myopathy and suggests a novel genotype-phenotype correlation.
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Ibdah JA, Tein I, Dionisi-Vici C, Bennett MJ, IJlst L, Gibson B, Wanders RJ, Strauss AW
Mild trifunctional protein deficiency is associated with progressive neuropathy and myopathy and suggests a novel genotype-phenotype correlation.
J Clin Invest. 1998 Sep 15;102(6):1193-9.
- PubMed ID
- 9739053 [ View in PubMed]
- Abstract
Human mitochondrial trifunctional protein (TFP) is a heterooctamer of four alpha- and four beta-subunits that catalyzes three steps in the beta-oxidation spiral of long-chain fatty acids. TFP deficiency causes a Reye-like syndrome, cardiomyopathy, or sudden, unexpected death. We delineated the molecular basis for TFP deficiency in two patients with a unique phenotype characterized by chronic progressive polyneuropathy and myopathy without hepatic or cardiac involvement. Single-stranded conformation variance and nucleotide sequencing identified all patient mutations in exon 9 of the alpha-subunit. One patient is homozygous for the T845A mutation that substitutes aspartic acid for valine at residue 246. The second patient is a compound heterozygote for the T914A that substitutes asparagine for isoleucine at residue 269 and a C871T that creates a premature termination at residue 255. Allele-specific oligonucleotide hybridization studies revealed undetectable levels of the mRNA corresponding to the mutant allele carrying the termination codon. This study suggests a novel genotype-phenotype correlation in TFP deficiency; that is, mutations in exon 9 of the alpha-subunit, which encodes a linker domain between the NH2-terminal hydratase and the COOH-terminal 3-hydroxyacyl-CoA dehydrogenase, result in a unique neuromuscular phenotype.