系统性红斑狼疮继发干燥综合征合并Fabry病患者家系的酶活性和基因分析

The enzymatic activity and genetic analysis of a family with one patient who have both systemic lupus erythematosus with secondary Sjoegren＇s syndrome and Fabry disease

目的分析1例系统性红斑狼疮（SLE）合并Fabry病患者家系临床资料、酶学和基因学的特点。方法收集患者及其家系成员的临床资料，抽取患者家系中3名成员外周血，底物荧光法进行酶活性检测，并对其中1名酶活性显著降低的男性家系成员进行基因组DNA提取，对GLA基因的7个外显子和旁侧内含子的序列进行聚合酶链反应（PCR）产物直接测序，检测是否存在突变。结果家系中2名成员外周血白细胞酶活性降低；其中的男性家系成员的基因检测显示GLA基因外显子2有错义突变：c．334C〉T（CGC〉TGC）（p．R112C）；除先证者本人外，其他家系成员均无明确的SLE证据。结论SLE合并Fabry病极其罕见；对于难以鉴别的患者需及时进行自身抗体及GLA酶学或者基因学的检测。

Objective To analyze the clinical information of a family with one patient who have systemic lupus erythematosus （SLE） and Fabry disease, as well as the enzymatic activity and gene mutation in these family members. Methods Clinical characteristics were collected from the proband and her family members. Peripheral blood samples from three members of this family were collected and the enzymatic activity was measured by fluorimetric substrate assay. Genomic DNA was extracted from one male member with significantly decreased enzyme activity, the 7 exons and their flanking introns of GLA gene were amplified by PCR and directly sequenced. Results The enzyme activity of two family members was significantly decreased, the genetic analysis of the male member revealed a missense mutation in exon 2： c.334C〉T （CGC〉TGC）（p.R112C）. Family members except the proband had no definite evidence to support the presence of SLE. Conclusion The coexistence of SLE and Fabry disease is extremely rare. Immunological test, enzymatic activity and gene mutation analysis seem to be helpful for the differential diagnosis.