Demirci F Yesim K, Radak Amy L, Rigatti Brian W, Mah Tammy S, Gorin Michael B
Department of Ophthalmology, School of Medicine, 203 Lothrop Street, Room 1027, Pittsburgh, PA 15213, USA.
Am J Ophthalmol. 2004 Sep;138(3):504-5. doi: 10.1016/j.ajo.2004.04.019.
A patient with retinitis pigmentosa demonstrated a novel RPGR mutation (213G>A, last base of exon 2) predicted to cause a missense change (G52R) in the final protein. This study was performed to determine whether this mutation altered the effectiveness of the adjacent splice site.
Observational case report.
Total RNA was extracted from leukocytes of the proband and his carrier mother. Reverse transcription-polymerase chain reaction (RT-PCR) was performed by using the primers flanking exon 2 of RPGR transcript, followed by gel purification and direct sequencing.
Sequencing revealed skipping of exon 2 in the mutated transcript, leading to in-frame deletion of 42 amino acids affecting the critical RCC1-like domain.
The last base of exons is conserved as "G" in 80% of splicing consensus sequences, yet when changed, can completely disrupt constitutive splicing as in this patient. Our data confirm that the evaluation of the effects of some DNA sequence alterations at the RNA level might have important implications for appropriate genotype-phenotype correlations.
一名视网膜色素变性患者表现出一种新的RPGR突变（213G>A，外显子2的最后一个碱基），预计该突变会导致最终蛋白质出现错义变化（G52R）。进行本研究以确定该突变是否改变了相邻剪接位点的有效性。
观察性病例报告。
从先证者及其携带者母亲的白细胞中提取总RNA。使用位于RPGR转录本外显子2两侧的引物进行逆转录-聚合酶链反应（RT-PCR），随后进行凝胶纯化和直接测序。
测序显示突变转录本中外显子2跳跃，导致42个氨基酸的框内缺失，影响关键的RCC1样结构域。
外显子的最后一个碱基在80%的剪接共有序列中保守为“G”，但发生改变时，如本患者，可完全破坏组成性剪接。我们的数据证实，在RNA水平评估某些DNA序列改变的影响可能对适当的基因型-表型相关性具有重要意义。
