新视角 | 使用全外显子测序鉴定新生儿脑病的遗传致病基因

基因检测与解读 · 公众号 · · 2017-08-21 07:04

正文

目的：新生儿脑病的特点是意识水平降低，发生在1-7 / 1,000的新生儿中。其中有半数以上没有找到明确的病因。作为前瞻性队列研究，我们对新生儿脑病患儿应用全外显子测序以确定内在的遗传原因的。

方法：

招募没有围产期窒息病史的新生儿脑病患儿，对父母及患儿进行trio全外显子测序。

结果：

19名患者符合纳入标准，由于撤回知情同意书、没有父母DNA样本或WES之前的遗传诊断，排除了5名患者。14名患者进行全外显子测序分析。我们明确了5例患者（36％）的遗传致病基因：常染色体显性相关的癫痫性脑病（新发突变）SCN2A（p.Met1545Val），KCNQ2（p.Asp212Tyr）和GNAO1（p.Gly40Arg），由于LIAS基因（p.Ala253Pro和p.His236Gln）中的复合杂合变体导致的硫辛酸合成酶缺乏; 与CUL4B（p.Asn211Ser）中的X染色体连锁相关的脑病。

结论：

WES有助于新生儿脑病和/或癫痫发作和脑损伤的遗传分子诊断。这将增加我们的理解，并可能使我们制定有针对性的神经保护治疗策略。

PMID: 28817111

文章图片

Functional analysis of p.Asn211SerCUL4Bvariant. (a) Reduced protein level of CUL4B in patient lymphoblasts with p.Asn211Ser CUL4B variant compared with control lymphoblasts (indicated by the arrow). (b) Reduced stability of p.Asn211Ser CUL4B variant. (c) Formation of ubiquitin ligase complex by p.Asn211Ser CUL4B variant. The arrow indicates reduced expression of p.Asn211Ser CUL4B compared with wild-type CUL4B. CHX, cycloheximide (25 μg/ml); CSN5, COP9 signalosome subunit 5; CUL4ANEDD8, NEDD8-modified CUL4A; CUL4BNEDD8, NEDD8-modified CUL4B; DDB1, damage-specific DNA binding protein 1; IP, immunoprecipitation; ROC1, regulator of cullins-1.

Activity of AACS G632S variant. (a) FLAG-hAACS-1 and -2 vectors or FLAG-hAACS-G632S-1 and -2 vectors were isolated from the separate bacterial colonies. The empty FLAG-hAACS or FLAG-hAACS-G632S vectors were transfected into the HEK 293 cell line. After 2 days of culture, the cells were harvested in the TNE buffer. AACS activity in 50 μg of protein extracts was assayed by measuring acetyl-CoA formation, as described in “Materials and Methods.” Data are representative of three independent experiments. Error bars indicate the SD (b) Each cell lysate (7.5 μg of protein) was subjected to western blotting to detect human AACS, FLAG, and GAPDH (glyceraldehyde 3-phosphate dehydrogenase).