目的 对1例Canavan病(CD)患儿进行临床表型及遗传学分析。 方法 选取1例因"发现竖头不稳2个月,四肢肌张力高1周"于2021年4月9日就诊于山东大学附属儿童医院的患儿进行高通量全外显子组测序检测,并对候选变异进行Sanger测序家系验证。 结果 测序结果显示患儿ASPA基因存在父源c.556_559dupGTTC(p.L187Rfs*5)和母源c.919delA(p.S307Vfs*24)复合杂合变异。根据美国医学遗传学与基因组学学会变异相关指南,二者均被评级为致病性变异(PVS1+PM2_Supporting+PM3)。 结论 ASPA基因c.556_559dupGTTC(p.L187Rfs*5)和c.919delA(p.S307Vfs*24)复合杂合变异可能是该CD患儿的致病原因。 Objective To analyze the clinical phenotype and genetic characteristics for a child with Canavan disease. Methods A child who was admitted to the Children's Hospital Affiliated to Shandong University on April 9, 2021 for inability to uphold his head for 2 months and increased muscle tone for one week was subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing. Results Genetic testing revealed that the child has harbored compound heterozygous variants of the ASPA gene, including a paternally derived c. 556_559dupGTTC (p. L187Rfs*5) and a maternally derived c.919delA (p. S307Vfs*24). Based on the guidelines from the American College of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+ PM2_Supporting+ PM3). Conclusion The c. 556_559dupGTTC (p.L187Rfs*5) and c. 919delA (p.S307Vfs*24) compound heterozygous variants of the ASPA gene probably underlay the pathogenesis of Canavan disease in this child.
Clinical and genetic analysis of a child with Canavan disease due to compound heterozygous variants ofASPA gene
Objective To analyze the clinical phenotype and genetic characteristics for a child with Canavan disease. Methods A child who was admitted to the Children's Hospital Affiliated to Shandong University on April 9, 2021 for inability to uphold his head for 2 months and increased muscle tone for one week was subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing. Results Genetic testing revealed that the child has harbored compound heterozygous variants of the ASPA gene, including a paternally derived c. 556_559dupGTTC (p. L187Rfs*5) and a maternally derived c.919delA (p. S307Vfs*24). Based on the guidelines from the American College of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+ PM2_Supporting+ PM3). Conclusion The c. 556_559dupGTTC (p.L187Rfs*5) and c. 919delA (p.S307Vfs*24) compound heterozygous variants of the ASPA gene probably underlay the pathogenesis of Canavan disease in this child.