Department of Neurology, China-Japan Union Hospital of Jilin University, No 126, Xiantai Street, Changchun, Jilin, China.
Medicine (Baltimore). 2021 Dec 17;100(50):e28008. doi: 10.1097/MD.0000000000028008.
Spinocerebellar ataxia (SCA) is a common neurogenetic disease that mainly manifests as ataxia of posture, gait, and limbs, cerebellar dysarthria, and cerebellar and supranuclear eye movement disorders. SCA has been found to include many subtypes, which are mainly mapped to 2 genetic patterns: autosomal dominant cerebellar ataxia and autosomal recessive cerebellar ataxia. Molecular genetic diagnosis functions as a necessity in its clinical diagnosis and treatment. In preliminary clinical work, we identified a family of SCA28 with rare gene mutation.
There are 5 patients in this family. The proband is a 32 year-old male, he mainly manifest unsteady steps for more than 7 months. The daughter of his younger maternal uncle gradually had unsteady steps and unclear speech for 5 years. The proband's mother, uncle and grandfather had similar symptoms, but they all died.
After Brain magnetic resonance imaging, whole exome sequencing and Sanger validation, the patients presented a c.1852A > G missense mutation in the exon region of AFG3L2 gene. The other family members revealed no AFG3L2 mutations. SCA28 is the one uniquely caused by a pathogenic variation in the mitochondrial protein AFG3L2. Combined with the clinical manifestations, auxiliary examinations and sequencing results of the patients (III-3 and III-5), the diagnosis of SCA28 was suspected.
The patients did not receive any drug treatment and the proband receive rehabilitation treatment.
The symptoms of ataxia were still progressively aggravated.
Molecular genetic diagnosis is necessary for ataxia. We here report the case and review the literature.
脊髓小脑共济失调（SCA）是一种常见的神经遗传性疾病，主要表现为姿势、步态和四肢共济失调、小脑性构音障碍以及小脑和核上性眼球运动障碍。已发现 SCA 包括许多亚型，主要映射到 2 种遗传模式：常染色体显性小脑共济失调和常染色体隐性小脑共济失调。分子遗传学诊断是其临床诊断和治疗的必要条件。在初步临床工作中，我们鉴定了一个 SCA28 家系，该家系存在罕见的基因突变。
该家系共有 5 位患者。先证者为 32 岁男性，主要表现为不稳步态 7 个月余。其舅舅的小女儿逐渐出现步态不稳和言语不清 5 年。先证者的母亲、舅舅和爷爷均有类似症状，但均已去世。
颅脑磁共振成像、外显子组测序和 Sanger 验证后，患者在 AFG3L2 基因外显子区域存在 c.1852A > G 错义突变。其他家族成员未发现 AFG3L2 突变。SCA28 是由线粒体蛋白 AFG3L2 上的致病性变异引起的独特疾病。结合患者（III-3 和 III-5）的临床表现、辅助检查和测序结果，疑诊 SCA28。
患者未接受任何药物治疗，仅予先证者康复治疗。
目前患者的共济失调症状仍逐渐加重。
对共济失调患者进行分子遗传学诊断是必要的。我们在此报告病例并复习文献。
