眼皮肤白化病近亲婚配一家系的MATP基因致病性新突变

Identification of a novel pathogenic mutation in MATP gene with oculocutaneous albinism type Ⅳ from a consanguineous marriage family

目的 对1例近亲婚配所致的眼皮肤白化病（OCA）患者相关基因进行研究,确定致病基因并阐明突变类型.方法 应用聚合酶链反应、DNA序列测定、基于PCR的染色体步移技术（PCR-Walking）、横跨越断裂点的单管多重PCR（Gap-PCR）和生物信息学分析方法,对患者家系进行突变筛查和新突变鉴定.结果 患者膜相关转运蛋白（MATP）基因存在包含整个外显子3在内的6365 bp大片段缺失,缺失范围为c.562-1118（±2）_c.885＋ 4923（±2）.该突变为OCA4型致病性突变,患者基因型为该缺失突变纯合子.结论 首次发现并确定了一种OCA4型大片段缺失突变.

Objective To clarify the pathogencity-related genes and its mutations in an oculocutaneous albinism （OCA） patient from a consanguineous marriage family. Methods Polymerase chain reaction （PCR） and automatic DNA sequencing methods,chromosome walking by PCR amplification techniques （PCR-Walking）,multiplex PCR in a single PCR tube with 3 primers bridging the breakpoint （Gap-PCR） and bioinformatic analysis were employed for screening the mutations and identifying the novel mutation in the patient and his family.Results A pathogenic deletion of 6365 bp was found in MATP gene with a range of c.562-1118 （ ± 2 ） to c.885 ＋ 4923 （ ± 2）.The patient was homozygous for deletion mutation.Conclusion A large deletion mutation was first detected and identified in OCA4.