过度惊吓反应症临床及遗传学特征（附６例报告）

目的　分析6例过度惊吓反应症患儿的临床及遗传学特征。 方法　对2011年6月至2018年5月于北京大学第一医院诊断的6例过度惊吓反应症患儿的临床表现、诊治过程、脑电图（EEG）及神经影像学、遗传学结果等进行分析。 结果　6例中男5例、女1例。6例均为新生儿早期起病，均可因不经意的听觉或触觉刺激诱发过度惊跳反应和全身僵硬症状，3例曾出现短暂窒息发作，1例曾惊吓后摔倒致外伤。6例点鼻反射均阳性，4例合并疝。EEG示1例正常，5例为不典型放电或一过性异常。4例曾行头颅磁共振检查未见明显异常。经遗传学分析，6例中3例携带GLRA1基因杂合突变，2例携带GLRB基因复合杂合突变，1例经全外显子测序未发现基因突变。6例给予氯硝西泮治疗， 1例全身僵硬及过度惊吓反应均基本消失， 5例全身僵硬症状消失、偶有惊跳反应。6例智力发育均正常，2例存在宽基底步态状行走姿势。1例有相同症状而窒息死亡的明确家族史。 结论　过度惊吓反应症具有典型临床表现，点鼻反射阳性，可行基因诊断确诊。该病对氯硝西泮有良好的治疗反应。早期经临床诊断及基因确诊，及时、恰当治疗，对于改善预后至关重要。     

过度惊吓反应症临床及遗传学特征（附６例报告）

目的　分析6例过度惊吓反应症患儿的临床及遗传学特征。 方法　对2011年6月至2018年5月于北京大学第一医院诊断的6例过度惊吓反应症患儿的临床表现、诊治过程、脑电图（EEG）及神经影像学、遗传学结果等进行分析。 结果　6例中男5例、女1例。6例均为新生儿早期起病,均可因不经意的听觉或触觉刺激诱发过度惊跳反应和全身僵硬症状,3例曾出现短暂窒息发作,1例曾惊吓后摔倒致外伤。6例点鼻反射均阳性,4例合并疝。EEG示1例正常,5例为不典型放电或一过性异常。4例曾行头颅磁共振检查未见明显异常。经遗传学分析,6例中3例携带GLRA1基因杂合突变,2例携带GLRB基因复合杂合突变,1例经全外显子测序未发现基因突变。6例给予氯硝西泮治疗, 1例全身僵硬及过度惊吓反应均基本消失, 5例全身僵硬症状消失、偶有惊跳反应。6例智力发育均正常,2例存在宽基底步态状行走姿势。1例有相同症状而窒息死亡的明确家族史。 结论　过度惊吓反应症具有典型临床表现,点鼻反射阳性,可行基因诊断确诊。该病对氯硝西泮有良好的治疗反应。早期经临床诊断及基因确诊,及时、恰当治疗,对于改善预后至关重要。     

A novel GLRA1 mutation in a recessive hyperekplexia pedigree.

We report the identification of a novel Y228C mutation within the M1 trans-membrane domain of the GLRA1 subunit of the glycine receptor responsible for a severe recessive hyperekplexia phenotype in a Kurdish pedigree.     

GLRA1 基因突变致过度惊吓反应症1 例临床及遗传学分析

目的总结GLRA1基因突变致过度惊吓反应症的临床及遗传学特点。方法回顾性分析2019年7月就诊的1例过度惊吓反应症患儿的临床资料。结果患儿男性,2个月29天,新生儿期起在突然的外界刺激后出现过度惊吓反应,全身僵硬、四肢肌张力增高;点鼻反射阳性。同期脑电图未见发作期图形。实验室及神经影像学检查均无特殊。全外显子测序证实患儿GLRA1基因(NM_000171.3),c.920AG杂合错义突变,其父母均未见突变,为新生突变。该错义突变目前国际上未见报道,根据美国医学遗传学与基因组学学会(ACMG)指南该变异为疑似致病。患儿经氯硝西泮口服治疗后症状较前明显改善,但四肢肌张力仍偏高。结论该患儿为GLRA1基因变异而致过度惊吓反应症,基因分析有助早期诊断及治疗。     

氯硝西泮治疗GLRA基因突变致过度惊吓反应征1例

目的：总结1例新生儿过度惊吓反应征的临床诊疗及遗传学特点,提高对该病的认识。方法：对2019年7月就诊于我院的1例过度惊吓反应征患儿临床诊疗、随访过程进行总结,并在CNKI、PubMed及万方数据库等检索查询时限建库起至2020年2月,对国内外过度惊吓反应征伴GLRA基因突变病例进行总结分析。结果：患儿,男,因“生后肌张力增高,哭声尖锐、单调、伴惊跳”收治,症状每日持续存在。查体见点鼻试验阳性,肌张力增高;实验室检查、脑电图及神经影像学检查均无明显异常,诊断过度惊吓反应征,基因分析回报GLRA1基因变异,患儿为新发变异。予口服氯硝西泮治疗,经治疗2周后患儿上述症状缓解。末次随访年龄为7月余,哭声同正常同龄儿童,未再出现惊跳及全身僵硬症状,生长发育同正常同龄儿。结论：点鼻试验阳性对过度惊吓反应征初筛重要,基因检测可用于进一步确诊     

Identification of the microdeletion breakpoint in a GLRA1null allele of Turkish hyperekplexia patients

Hyperekplexia (startle disease) is a hereditary motor disease caused by mutations within the GLRA1 gene (Chr. 5q33.1), which encodes the alpha1 subunit of the inhibitory glycine receptor (GlyR). While most patients are diagnosed with dominant hyperekplexia associated with point mutations within or adjacent to the channel pore, recessive hyperekplexia is less frequent. Here, we report five new pedigrees of recessive hyperekplexia in apparently unrelated families of Kurdish origin associated with a deletion of exons 1-7 of the GLRA1 gene. The deletion was identical in all families, encompassing 329 Kb of genomic sequence. No other known functional genes were involved, indicating that the GLRA1null allele is distinct from the 5q syndrome. Analysis of the DNA sequence flanking the proximal and distal breakpoint revealed no significant homology of sequences immediately adjacent to the breaks. Consensus sites for Toposiomerase II were detected close to the breakpoint compatible with an illegitimate recombination event. No heterozygous carriers of the deletion allele were detected by screening of 500 individuals from the southeastern Mediterranean region belonging to four different ethnic groups. Hence, the identical nature of the breakpoint junction in all patients and carriers suggests a founder mutation in an ethnic population originating from Turkey.     

Effects of functional knock-out of alpha 1 glycine-receptors on breathing movements in oscillator mice

The effects of a deficiency of glycinergic inhibition deriving from mutations of the glycine-receptor gene Glra1 on the breathing pattern of oscillator mice were studied. We compared the development of breathing frequency, tidal volume and minute ventilation from control mice (wild type- and heterozygous oscillator mice) with those of homozygous oscillator mice during early postnatal periods from p9 until p21. The changes of ventilation were correlated with body-weight and changes in blood-pH. During the second to third weeks of postnatal development, breathing frequency increased from 310 to 445.4 mm-1 in control mice. Oscillator mice reached a maximal value of 313.3 min-1 at p18 followed by a fast decrease to 233.0 min-1. This decrease is caused by a prolongation of expiratory duration. Tidal volume showed a steady increase from 6.6 to 15.1 microliters in control animals. In comparison, oscillator mice showed significant lower values after p14. After p15, minute ventilation of oscillator mice declined as compared with control animals leading to respiratory acidosis at p20.