Novel <it>SCARB2 </it>mutation in action myoclonus-renal failure syndrome and evaluation of <it>SCARB2 </it>mutations in isolated AMRF features

oleh: Hopfner Franziska, Schormair Barbara, Knauf Franziska, Berthele Achim, Tölle Thomas R, Baron Ralf, Maier Christoph, Treede Rolf-Detlef, Binder Andreas, Sommer Claudia, Maihöfner Christian, Kunz Wolfram, Zimprich Friedrich, Heemann Uwe, Pfeufer Arne, Näbauer Michael, Kääb Stefan, Nowak Barbara, Gieger Christian, Lichtner Peter, Trenkwalder Claudia, Oexle Konrad, Winkelmann Juliane

Format: Article
Diterbitkan: BMC 2011-10-01

Deskripsi

<p>Abstract</p> <p>Background</p> <p>Action myoclonus-renal failure syndrome is a hereditary form of progressive myoclonus epilepsy associated with renal failure. It is considered to be an autosomal-recessive disease related to loss-of-function mutations in <it>SCARB2</it>. We studied a German AMRF family, additionally showing signs of demyelinating polyneuropathy and dilated cardiomyopathy.</p> <p>To test the hypothesis whether isolated appearance of individual AMRF syndrome features could be related to heterozygote <it>SCARB2 </it>mutations, we screened for <it>SCARB2 </it>mutations in unrelated patients showing isolated AMRF features.</p> <p>Methods</p> <p>In the AMRF family all exons of <it>SCARB2 </it>were analyzed by Sanger sequencing. The mutation screening of unrelated patients with isolated AMRF features affected by either epilepsy (n = 103, progressive myoclonus epilepsy or generalized epilepsy), demyelinating polyneuropathy (n = 103), renal failure (n = 192) or dilated cardiomyopathy (n = 85) was performed as high resolution melting curve analysis of the <it>SCARB2 </it>exons.</p> <p>Results</p> <p>A novel homozygous 1 bp deletion (c.111delC) in <it>SCARB2 </it>was found by sequencing three affected homozygous siblings of the affected family. A heterozygous sister showed generalized seizures and reduction of nerve conduction velocity in her legs. No mutations were found in the epilepsy, renal failure or dilated cardiomyopathy samples. In the polyneuropathy sample two individuals with demyelinating disease were found to be carriers of a <it>SCARB2 </it>frameshift mutation (c.666delCCTTA).</p> <p>Conclusions</p> <p>Our findings indicate that demyelinating polyneuropathy and dilated cardiomyopathy are part of the action myoclonus-renal failure syndrome. Moreover, they raise the possibility that in rare cases heterozygous <it>SCARB2 </it>mutations may be associated with PNP features.</p>