Phenotypical characteristics of idiopathic infantile nystagmus with and without mutations in FRMD7
Phenotypical characteristics of idiopathic infantile nystagmus with and without mutations in FRMD7
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DOI：
10.1093/brain/awn046
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发表时间：
2008-05-01
期刊：
影响因子：
14.5
通讯作者：
Gottlob, Irene
中科院分区：
文献类型：
--
作者：
Thomas, Shery;Proudlock, Frank A.;Gottlob, Irene
特发性婴儿眼震（IIN）是由眼睛的不自主振荡。家族型最常见的是X连锁。我们最近发现了一个新的基因FRMD7（Xq26.2）的突变，这提供了一个机会，调查一个遗传定义和同质组的眼震患者。我们比较了90例基因突变受试者（FRMD7组）与48例无突变但具有临床IIN的受试者（非FRMD7组）的临床特征和眼动记录。还调查了58名女性专性突变携带者。两组的中位视力（VA）均为0.2 logMAR（Snellen等效值6/9），大多数患者具有良好的立体视觉。斜视的患病率也相似（FRMD 7：7.8，非FRMD 7：10）。在非FRMD7组中，异常头部姿势（AHP）的存在显著更高（P <0.0001）。与非FRMD7组（P = 0.83）相比，FRMD7组的眼震幅度更强烈地依赖于注视方向，在初始位置较低（P <0.0001）。在FRMD 7组中，摆动性眼震波形也更常见（P = 0.003）。53%的FRMD7突变的女性携带者在临床上受到影响。受累女性的VA略好于受累男性（P = 0.014）。亚正常视动反应被发现在一个亚组的专性未受影响的运营商，这可能被解释为亚临床表现。FRMD7是X连锁IIN的主要原因。FRMD7组和非FRMD7组的大多数临床和眼球运动特征相似，大多数患者具有良好的VA和立体视觉，斜视发生率较低。FRMD7组中较少的患者发生AHPs，他们的眼震振幅在初始位置较低。我们的研究结果有助于IIN的临床识别和眼球震颤患者的遗传咨询。
Idiopathic infantile nystagmus (IIN) consists of involuntary oscillations of the eyes. The familial form is most commonly X-linked. We recently found mutations in a novel gene FRMD7 (Xq26.2), which provided an opportunity to investigate a genetically defined and homogeneous group of patients with nystagmus. We compared clinical features and eye movement recordings of 90 subjects with mutation in the gene (FRMD7 group) to 48 subjects without mutations but with clinical IIN (non-FRMD7 group). Fifty-eight female obligate carriers of the mutation were also investigated. The median visual acuity (VA) was 0.2 logMAR (Snellen equivalent 6/9) in both groups and most patients had good stereopsis. The prevalence of strabismus was also similar (FRMD7: 7.8, non-FRMD7: 10). The presence of anomalous head posture (AHP) was significantly higher in the non-FRMD7 group (P < 0.0001). The amplitude of nystagmus was more strongly dependant on the direction of gaze in the FRMD7 group being lower at primary position (P < 0.0001), compared to non-FRMD7 group (P = 0.83). Pendular nystagmus waveforms were also more frequent in the FRMD7 group (P = 0.003). Fifty-three percent of the obligate female carriers of an FRMD7 mutation were clinically affected. The VAs in affected females were slightly better compared to affected males (P = 0.014). Subnormal optokinetic responses were found in a subgroup of obligate unaffected carriers, which may be interpreted as a sub-clinical manifestation. FRMD7 is a major cause of X-linked IIN. Most clinical and eye movement characteristics were similar in the FRMD7 group and non-FRMD7 group with most patients having good VA and stereopsis and low incidence of strabismus. Fewer patients in the FRMD7 group had AHPs, their amplitude of nystagmus being lower in primary position. Our findings are helpful in the clinical identification of IIN and genetic counselling of nystagmus patients.