Laboratory of Molecular Virology and Biological Chemistry, Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland.
J Med Virol. 2014 Aug;86(8):1421-7. doi: 10.1002/jmv.23906. Epub 2014 Feb 21.
Cytomegalovirus (CMV) is a leading cause of congenital infection and a leading infectious cause of hearing loss in children. The ORF UL75 gene encodes envelope glycoprotein H (gH), which is essential for CMV entry into host cells and the target of the immune response in humans. However, the distribution of gH variants and the relationship between the viral genotype, viral load, and sequelae in children infected with CMV is debated. The UL75 genetic variation of CMV isolates from 42 newborns infected congenitally with CMV and 93 infants with postnatal or unproven congenital CMV infection was analyzed. Genotyping was performed by analysis of PCR-amplified fragments, and the viral load was measured by quantitative real-time PCR. There were no differences in the distribution of gH genotypes in the children infected congenitally and postnatally. Mixed-genotype infections with both gH1 and gH2 variants were detected in approximately 25% of the examined patients. No relationship between UL75 gene polymorphisms and the symptoms at birth was observed. The results suggest that the infection with gH2 genotype diminishes the risk of hearing loss in children (P = 0.010). In addition, sensorineural hearing loss was associated with CMV gH1 genotype infection in infants (P = 0.032) and a high viral load in urine (P = 0.005). In conclusion, it was found that the gH genotype does not predict clinical sequelae in newborn infants following congenital CMV infection. However, these results suggest that the gH genotype might be associated with hearing loss in children.
巨细胞病毒（CMV）是先天性感染的主要原因，也是儿童听力损失的主要感染原因。ORF UL75 基因编码包膜糖蛋白 H（gH），它是 CMV 进入宿主细胞的必需因素，也是人类免疫反应的靶标。然而，CMV 感染儿童中 gH 变体的分布以及病毒基因型、病毒载量和后遗症之间的关系仍存在争议。分析了 42 例先天性 CMV 感染新生儿和 93 例后天性或未经证实的先天性 CMV 感染婴儿的 CMV 分离株的 UL75 基因变异。通过分析 PCR 扩增片段进行基因分型，通过定量实时 PCR 测量病毒载量。先天性和后天性感染儿童的 gH 基因型分布无差异。约 25%的检查患者中检测到 gH1 和 gH2 变体的混合基因型感染。未观察到 UL75 基因多态性与出生时症状之间的关系。结果表明，gH2 基因型感染降低了儿童听力损失的风险（P=0.010）。此外，感觉神经性听力损失与婴儿中 CMV gH1 基因型感染（P=0.032）和尿液中高病毒载量（P=0.005）相关。总之，发现 gH 基因型不能预测先天性 CMV 感染后新生儿的临床后遗症。然而，这些结果表明 gH 基因型可能与儿童听力损失有关。
