Okinaka R T, Perez-Castro A V, Sena A, Laubscher K, Strniste G F, Park M S, Hernandez R, MacInnes M A, Kraemer K H
Life Sciences Division, Los Alamos National Laboratory, NM 87545, USA.
Mutat Res. 1997 Nov;385(2):107-14. doi: 10.1016/s0921-8777(97)00031-1.
A search for genetic alterations within the XPG gene has been conducted on skin and blood cells cultured from a newly characterized xeroderma pigmentosum (XP) patient (XP20BE). This patient is the ninth known case that falls into the extremely rare XP complementation group G. Four genetic markers within the XPG gene (including two polymorphisms) demonstrated the Mendelian distribution of this gene from the parents to the patient and to an unaffected sibling. The patient (XP20BE) inherited a G to T transversion from his father in exon 1 of the XPG gene that resulted in the conversion of a glutamic acid at codon 11 to a termination codon. The patient also inherited an XP-G allele from his mother that produces an unstable or poorly expressed message. The cause of the latter defect is still uncertain. In addition to these alterations, XP20BE cDNA contained an mRNA species with a large splicing defect that encompassed a deletion from exon 1 to exon 14. This splicing defect, however, appears to be a naturally occurring low-frequency event that results from abnormal splicing that occurs between certain conserved non-consensus splicing signals within the human XPG gene.
对一名新鉴定的着色性干皮病（XP）患者（XP20BE）培养的皮肤和血细胞进行了XPG基因内基因改变的研究。该患者是已知的第九例属于极其罕见的XP互补组G的病例。XPG基因内的四个遗传标记（包括两个多态性）显示该基因从父母遗传给患者和一名未受影响的同胞时呈孟德尔分布。患者（XP20BE）在XPG基因外显子1中从父亲那里继承了一个从G到T的颠换，导致密码子11处的谷氨酸转换为终止密码子。患者还从母亲那里继承了一个XP - G等位基因，该等位基因产生不稳定或表达不佳的信息。后一种缺陷的原因仍不确定。除了这些改变外，XP20BE cDNA包含一种具有大剪接缺陷的mRNA种类，该缺陷包括从外显子1到外显子14的缺失。然而，这种剪接缺陷似乎是一种自然发生的低频事件，是由人类XPG基因内某些保守的非共识剪接信号之间发生的异常剪接导致的。
