PURPOSE: To determine whether two families diagnosed with X-linked retinoschisis contained mutations in the XLRS1 gene. METHODS: DNA from the patients was obtained from blood lymphocytes using commercially available kits. Single-strand conformation assay was performed in an electrophoresis apparatus using 10% acrylamide TBE gels at 10 degrees C. The gels were stained with SYB green II and were scanned in a phosphoimager. DNA was sequenced using an automated fluorescence sequencer. RESULTS: A deletion that eliminates exon 2 was found in one family. An abnormal sequence replacement in exon 4 was found in the other family. Both mutations have severe effects in the coding region by inserting premature stop codons. CONCLUSIONS: Both of the families have mutations in the XLRS1 gene. One of these mutations points to a novel mechanism. The mutation is caused by a replacement of 17 bp of a normal sequence with 20 bp of a sequence originating from two different places in the antisense strand. This suggests that early Okazaki fragments were incorporated into the sense strand of exon 4, replacing the normal sequence.
PURPOSE: To determine whether two families diagnosed with X-linked retinoschisis contained mutations in the XLRS1 gene. METHODS: DNA from the patients was obtained from blood lymphocytes using commercially available kits. Single-strand conformation assay was performed in an electrophoresis apparatus using 10% acrylamideTBE gels at 10 degrees C. The gels were stained with SYB green II and were scanned in a phosphoimager. DNA was sequenced using an automated fluorescence sequencer. RESULTS: A deletion that eliminates exon 2 was found in one family. An abnormal sequence replacement in exon 4 was found in the other family. Both mutations have severe effects in the coding region by inserting premature stop codons. CONCLUSIONS: Both of the families have mutations in the XLRS1 gene. One of these mutations points to a novel mechanism. The mutation is caused by a replacement of 17 bp of a normal sequence with 20 bp of a sequence originating from two different places in the antisense strand. This suggests that early Okazaki fragments were incorporated into the sense strand of exon 4, replacing the normal sequence.
Authors: Jun Xu; Hong Gu; Kai Ma; Xipu Liu; Torkel Snellingen; Erdan Sun; Ningli Wang; Ningpu Liu Journal: Mol Vis Date: 2010-08-12 Impact factor: 2.367
Authors: F Simonelli; G Cennamo; C Ziviello; F Testa; G de Crecchio; A Nesti; M P Manitto; A Ciccodicola; S Banfi; R Brancato; E Rinaldi Journal: Br J Ophthalmol Date: 2003-09 Impact factor: 4.638