Charcot-Marie-Tooth phenotype produced by a duplicated PMP22 gene as part of a 17P trisomy-translocation to the X chromosome |
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| Authors: | PH King R Waldrop JR Lupski LG Shaffer |
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| Institution: | Department of Neurology, The University of Alabama at Birmingham, USA;Departments of Molecular and Human Genetics, Baylor College of Medicine, USA;Departments of Pediatrics, Baylor College of Medicine, USA |
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| Abstract: | The Charcot-Mane-Tooth disease type 1A (CMTlA) phenotype is most often associated with a 1.5 megabase (mb), tandem duplication of chromosome 17 band p12 (17˜12). The prevailing hypothesis is that the demyelinating neuropathy results from a dosage effect of the peripheral myelin protein gene PMP22 which is included within this duplication. We present a patient with clinical and electrophysiological features ofCMTlA in whom an extra PMP22 gene resulted from a rare unbalanced translocation of 17p to the X chromosome. This finding further supports the hypothesis of gene dosage as the basis for CMTlA. More-over, this case highlights the importance of fluorescence in siiu hybridization (FISH) as an alternative molecular technique in the diagnosis of CMTlA. |
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| Keywords: | Charcot-Marie Tooth neuropathy PMPZZ gene trisomy 17p gene dosage effect |
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