目的：使用Sanger测序法鉴定2个中国结晶样视网膜色素变性(BCD)家系中CYP4V2基因的突变位点。

方法：收集2019-01/09临床诊断为BCD患者的临床相关资料。采集患者、患者家系成员的外周血，提取DNA，利用Sanger测序法鉴定突变位点。

结果：共收集2个BCD先证者，先证者均表现为渐进性视力下降，眼底均可见典型的结晶样物质沉积。测序发现先证者1及其患病的哥哥，妹妹均在CYP4V2基因上存在c.802-8_810del17insGC的纯合突变。而先证者2则在CYP4V2基因上存在c.219T>A(p.F73L)、c.802-8_810del17insGC杂合突变。

结论： 中国BCD患者中最常见的c.802-8_810del17insGC突变在先证者1家系中为纯合突变，是其家系的致病突变。而先证者2则携带了中国BCD患者最常见的c.802-8_810del17insGC杂合突变，同时先证者2还携带c.219T>A(p.F73L)错义突变，突变均影响了CYP4V2基因的正常编码，进而导致疾病。

METHODS: The relevant clinical examination of BCD patients were collected. Peripheral blood of patients and their family members was collected. Then DNA was extracted from peripheral blood, and Sanger sequencing was used to identify mutation sites.

RESULTS: Two probands of BCD from different families were collected. All the probands showed progressive decrease of visual acuity and typical crystal-like material deposition could be seen in the fundus. Sanger sequencing showed that proband 1 and her brother and sister all had homozygous mutation of c.802-8_810del17insGC in CYP4V2 gene. On the other hand, proband 2 had a compound heterozygous mutation of c.219T>A(p.F73L)and c.802-8_810del17insGC in CYP4V2 gene.

CONCLUSION: The most common mutation was c.802-8_810del17insGC in Chinese BCD patients. The homozygous c.802-8_810del17insGC mutation was the cause of BCD in the proband 1 family. On the other hand, proband 2 had c.802-8_810del17insGC heterozygous mutation and c. 219T>A(p.F73L)heterozygous missence mutation, all of which affected the normal coding of CYP4V2 gene and led to disease.