Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China.
Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, China.
J Clin Lab Anal. 2020 Jan;34(1):e23012. doi: 10.1002/jcla.23012. Epub 2019 Sep 8.
Idiopathic infantile nystagmus (IIN) is a high genetically heterogeneous ophthalmic disease and is often associated with pathogenic mutations in FRMD7 and GPR143, respectively. Idiopathic infantile nystagmus manifests as involuntary periodic rhythmic oscillation of the eyes in the very early life, which decreases visual acuity and affects the quality of life.
The aim of our study was to reveal a possible pathogenic variant through the investigation of a Chinese Han family with IIN with an implementation of a next-generation sequencing method. Isolated DNA analysis was followed by Sanger sequencing validation. We also performed the detailed ophthalmological examination of family members.
We identified a novel frameshift variant in FRMD7 (NM_194277.2: c.1419_1422dup, p.Tyr475fs), which leads to a frameshift mutation since tyrosine (Tyr) at 475 codon of FRMD7 protein (p.Tyr475fs) and co-segregates with IIN phenotype in this family.
We found a novel frameshift FRMD7 variant in a Chinese Han family, which may be causative variant for IIN and can further enrich the mutation spectrum and uncover the etiology of IIN.
特发性婴儿性眼球震颤（IIN）是一种高度遗传异质性的眼科疾病，分别常与 FRMD7 和 GPR143 的致病突变相关。特发性婴儿性眼球震颤表现为婴儿早期眼睛不由自主的周期性节律性摆动，降低了视力，并影响了生活质量。
我们的研究目的是通过对一个患有 IIN 的中国汉族家庭进行下一代测序方法的研究，揭示一个可能的致病变体。对分离的 DNA 进行分析，然后进行 Sanger 测序验证。我们还对家庭成员进行了详细的眼科检查。
我们在 FRMD7 中发现了一个新的移码变异（NM_194277.2: c.1419_1422dup, p.Tyr475fs），导致移码突变，因为 FRMD7 蛋白的 475 位密码子的酪氨酸（Tyr）（p.Tyr475fs）发生了改变，并且与这个家系中的 IIN 表型共分离。
我们在中国汉族人群中发现了一个新的 FRMD7 移码变异，它可能是 IIN 的致病变异，可以进一步丰富突变谱，揭示 IIN 的病因。
