目的：为了评估视觉系统同源框1(VSX1)基因的突变和圆锥角膜(KCN)以及颗粒状角膜营养不良(GCD)之间的关联。

方法：对一个同时患有KCN和GCD的四代伊朗人家系进行了直接测序，鉴别出一个包含四代人同时患有GCD的伊朗KCN家系。从全血样品中提取基因组DNA。然后，为了研究KCN和GCD之间可能的连锁关系，通过PCR在每个样品中扩增VSX1基因的整个编码区和内含子-外显子边界。随后，对PCR产物进行直接测序，并在患者和对照组中进行突变分析。

结果：VSX1基因突变分析未发现KCN和GCD疾病与VSX1基因相关的证据。我们的数据排除了VSX1作为该特定家系中KCN / GCD致病基因的可能性。

结论：尽管患有GCD的KCN患者与VSX1基因变异无关联，但是仍需要对其它可能与KCN合并GCD发病机制相关的基因进行研究。

AIM: To evaluate association between mutations in the visual system homeobox 1(VSX1)gene and keratoconus(KCN)complicated with granular corneal dystrophy(GCD), direct sequencing was performed in an Iranian family affected by KCN and GCD in four generations.

METHODS: An Iranian pedigree with keratoconus spanning four generations along with GCD was identified. Whole blood sample was used for genomic DNA extraction. The molecular analysis by using polymerase chain reaction(PCR)of the entire coding region and intron-exon boundaries of VSX1 gene was preformed to investigate the possible linkage between KCN and GCD. Subsequently, direct sequencing was used for PCR products and mutation analysis was conducted in the patients and controls.

RESULTS: Mutation analysis in VSX1 gene did not detect evidence for association between KCN and GCD diseases and VSX1 gene. Our data excluded VSX1 as the disease-causing gene for KCN/GCD in this specific pedigree.

CONCLUSION: Despite of no association between KCN patients with GCD and VSX1 gene variations, other probable genes involved in pathogenesis of the KCN and GCD diseases need to be investigated in the patients.