Jiao Hui, Xiong Hui, Zhang Yan-zhi, Wang Shuo, Yang Yan-ling, Wu Xi-ru
Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2011 Oct;28(5):481-4. doi: 10.3760/cma.j.issn.1003-9406.2011.05.001.
To study the clinical feature of a Chinese family with muscle-eye-brain disease (MEB) and the mutation of protein O-linked-mannose beta-1, 2-N-acetylglucosaminyltransferase 1 gene (POMGNT1).
Clinical data of the proband and his family members were collected. Genomic DNA from the patient and his parents was extracted using standard procedures from the peripheral blood leukocytes. Polymerase chain reaction and DNA direct sequencing were employed to analyze all of the exons to determine the mutation, and the relationship between genotype and phenotype was analyzed.
The proband was diagnosed as floppy baby, presented with delayed psychomotor development and myopathic face. His serum creatine kinase (CK) level elevated moderately and brain MRI showed cerebral and cerebellar gyrus abnormalities with white matter signal intensity changes, cerebellar cysts and cerebellar and brain stem hypoplasia, consistent with congenital muscular dystrophy with eye brain disorder. Further test with DNA detected a compound heterozygous mutation of c.1896 1 G to C before exon 22 which may induce splicing error, and missense mutation c.1319T to G, p.L440R in exon 16. Both parents had a heterozygous mutation at the mutation sites.
According to our study, the family is diagnosed as MEB. The proband carried compound heterozygous mutations in the POMGNT1 gene, and his parents are heterozygous carriers, which is consistent with autosomal recessive inheritance. The child is definitely diagnosed as having muscle eye brain disease.
研究一个患有肌肉-眼-脑疾病(MEB)的中国家系的临床特征及蛋白O-连接甘露糖β-1,2-N-乙酰葡糖胺基转移酶1基因(POMGNT1)的突变情况。
收集先证者及其家庭成员的临床资料。采用标准程序从外周血白细胞中提取患者及其父母的基因组DNA。运用聚合酶链反应和DNA直接测序分析所有外显子以确定突变情况,并分析基因型与表型之间的关系。
先证者被诊断为松软儿,表现为精神运动发育迟缓及肌病面容。其血清肌酸激酶(CK)水平中度升高,脑部磁共振成像(MRI)显示大脑和小脑脑回异常伴白质信号强度改变、小脑囊肿以及小脑和脑干发育不全,符合先天性肌营养不良伴眼脑障碍。进一步的DNA检测发现外显子22之前存在c.1896 1 G>C的复合杂合突变,可能导致剪接错误,以及外显子16中的错义突变c.1319T>G,p.L440R。父母在突变位点均有杂合突变。
根据本研究,该家系被诊断为MEB。先证者在POMGNT1基因中携带复合杂合突变,其父母为杂合携带者,符合常染色体隐性遗传。该患儿被明确诊断为患有肌肉-眼-脑疾病。