Supplementary Material for: Screening for TSEN54 variant in Egyptian Patients with Ponto-Cerebellar Malformations.

Introduction: Pontocerebellar hypoplasia (PCH): represents a group of rare disorders with the mostly prenatal onset and time-dependent loss of brain parenchyma, predominantly affecting the cerebellum and pons with variable involvement of supratentorial structures. Radiologically and pathologically, they are characterized by small cerebellum and pons. Our study aimed to screen for the TSEN54 in Egyptian patients with PCH for proper counseling and to describe the brain MRI and the clinical phenotype and compare, them to those described in the literature.
Methods: Thirty patients from thirty Egyptian families with a diagnosis of PCH based on neuroimaging findings were selected. Clinical evaluation, radiological findings, and genetic investigations were done for all patients.
Results: The common missense variant c.919G>T (p.A307S) was identified in only six patients from six unrelated families (6/30; 20%) who showed different degrees of pontocerebellar malformations on brain imaging.
Conclusion: The presence of a Dragonfly/butterfly-like pattern in the coronal section of the cerebellum recommends genetic testing of TSEN54 as a first step. For negative cases, whole exome sequencing (WES) is essential to reach a definite diagnosis and determine the etiology.

引言：小脑脑桥发育不良（PCH）是一组罕见疾病，主要表现为产前发病，脑实质随时间推移而逐渐丧失，主要影响小脑和脑桥，并伴有对顶叶结构的不同程度侵犯。在影像学和病理学上，这些疾病以小脑和脑桥的缩小为特征。本研究旨在对埃及PCH患者进行TSEN54基因筛查，以提供适当的咨询，并描述脑部MRI、临床表型和文献中描述的表型进行比较。
方法：从三十个埃及家庭中选取了三十名基于神经影像学检查诊断为PCH的患者。对所有患者进行了临床评估、影像学检查和遗传学检测。
结果：在六个不同家族的六名患者中（6/30；20%），仅在脑部影像学检查中发现了c.919G>T（p.A307S）的常见错义变异，这些患者表现出不同程度的小脑脑桥畸形。
结论：小脑横断面出现类似蜻蜓或蝴蝶的图案，建议将TSEN54基因的遗传检测作为初步步骤。对于阴性病例，全外显子测序（WES）对于确诊和确定病因至关重要。