目的 对一个多发内分泌腺瘤病2A型(MEN2A)家系患者的临床特点及RET原癌基因突变情况进行分析.方法 收集先证者及其家系成员相关临床资料,提取1名先证者及10名家系成员的外周血基因组DNA,对RET基因所有外显子进行PCR扩增,对扩增产物进行测序分析.结果 家系中3位已发病患者的临床表现不同,但其RET原癌基因均同时存在3个错义突变,分别是位于11号外显子的C634R、G691S和位于18号外显子的R982C,而家系中其他成员则不存在上述突变.结论 当C634R与G691S、R982C多态性同时存在时,临床上主要表现为与单纯C634R突变一致的PET蛋白功能异常激活性疾病.%Objective To analyze the clinical characteristics and mutation of RET proto-oncogene in a pedigree with multiple endocrine neoplasia type 2A (MEN2A). Methods The clinical data of a proband and other 10 family members were collected, the genomic DNA of their peripheral blood were extracted, the overall exons of RET proto-oncogene were amplified by PCR, and the PCR products were then purified and direct DNA sequence analysis was performed. Results Different clinical features were found in three of the family members. Three missense mutations, C634R and G691S in exon 11 and R982C in exon 18, were detected in RET proto-oncogene. The three of family members had shown MEN2A related signs, and no such mutations were detected in the other family members. Conclusions Genetic screening set the diagnosis of MEN2A at the gene level, and help analyze the family members at risk. Patients in this case may show typical clinical manifestations of MEN2A, which indicates that C634R mutation combined with G691S and R982C polymorphisms lead to the increase of downstream signal activation of the RET protein as the single C634R mutation along does.
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