Heterozygous deletion of ITPR1, but not SUMF1 in spinocerebellar ataxia type 16
Akiko Iwaki 1, Yuji Kawano 1, Shiroh Miura 1, Hiroki Shibata 1, Dai Matsuse 1, Wei Li 1, Hirokazu Furuya 2, Yasumasa Ohyagi 1, Takayuki Taniwaki 1, Jun-ichi Kira 1 and Yasuyuki Fukumaki 1*
1 Kyushu University, Japan
2 National Omuta Hospital, Japan
* To whom correspondence should be addressed. E-mail: yfukumak{at}gen.kyushu-u.ac.jp.
Accepted 14 September 2007
 | Abstract |
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We have previously mapped autosomal dominant spinocerebellar ataxia (SCA) 16 to 3p26, overlapping with the locus of SCA15. Recently, partial deletions of ITPR1 and the neighboring SUMF1 in the SCA15 and two additional families were reported. In the present study we determined the copy number of these genes by real-time quantitative PCR and found a heterozygous deletion of exons 1-48 of ITPR1, but not SUMF1 in SCA16. Breakpoint analysis revealed that the size of the deletion is 313,318 bp and the telomeric breakpoint is located in the middle of their intergenic region. Our data provide evidence that haploinsufficiency of ITPR1 alone causes SCA16 and SCA15.
Keywords:
ITPR1, SCA16, SUMF1, deletion, haploinsufficiency
