The enzymatic activity and genetic analysis of a family with one patient who have both systemic lupus erythematosus with secondary Sj(o)gren's syndrome and Fabry disease / 中华风湿病学杂志

ABSTRACT

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 fluorimetrie 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 2c.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.