Same-sex twins have a high incidence of congenital hypothyroidism and a high probability to be missed at newborn screening.

BACKGROUND: We estimated the incidence of CH in twins, analyse the clinical features of CH cases in twins and further evaluate the CH screening strategy and recall procedures for twins. METHODS: A retrospective investigation of the screening results and confirmed cases in 724,791 newborns was conducted from 2015 to 2017 in Guangzhou. Clinical features were compared between twins with CH and singletons with CH. In addition, the twins were further divided into same-sex twins and different-sex twins to analyse the characteristics and incidence of CH and to compare differences in the confirmed cases in the 2 groups. RESULTS: The incidence of CH in same-sex twins was 1/593, which was much higher than the incidence of CH in singletons (1/1323) and different-sex twins (1/3060). Of the 20 twins diagnosed with CH, 17 were same-sex twins and 3 were different-sex twins. Among the six pairs of same-sex twins with CH, four had TSH inconsistency, which reached 67%. Eight of the 17 cases of same-sex twins diagnosed with CH had negative results at the first screening. CONCLUSIONS: Distinguishing same-sex twins from different-sex twins during newborn screening is more feasible. The incidence of CH in same-sex twins is much higher than that in the general population and the risk of transient CH is relatively high. In positive cases in same-sex twins, the simultaneous recall of the twin can effectively avoid a missed diagnosis. The screening center should properly evaluate the recall strategy and screening procedure for twins, especially twins of the same-sex.

[Characteristics of DUOXA2 gene mutation in children with congenital hypothyroidism].

OBJECTIVE: To investigate the characteristics of DUOXA2 gene mutation and the genotype-phenotype relationship in children with congenital hypothyroidism (CH) in Guangzhou, China. METHODS: A total of 20 CH patients with suspected thyroid dyshormonogenesis who had no DUOX2 gene mutation were enrolled. These patients who were born between 2011 and 2012 were screened and diagnosed with CH in the Guangzhou Newborn Screening Center. PCR and direct sequencing were used to analyze DUOXA2 gene mutation. RESULTS: Among the 20 patients, 2 had p.Y246X/p.Y246X homozygous mutation; 4 had monoallelic heterozygous mutation, among whom 2 carried the known pathogenic mutation c.413-414insA, 1 carried p.Y246X, and 1 carried a novel mutation, p.G79R. Reevaluation was performed at the age of 2-3 years, and the results showed that the two patients with p.Y246X/p.Y246X homozygous mutation were manifested as transient and mild permanent CH, respectively. Among the four patients with monoallelic heterozygous mutation, the one who carried p.Y246X mutation was manifested as typical permanent CH, and the other three were manifested as transient CH. CONCLUSIONS: DUOXA2 gene mutation is a common molecular pathogenic basis for CH children with suspected thyroid dyshormonogenesis in Guangzhou, and most of them are manifested as transient CH. There is no association between DUOXA2 genotypes and phenotypes. The novel mutation p.G79R is probably a pathogenic mutation.

Transcriptome de novo assembly and analysis of differentially expressed genes related to cytoplasmic male sterility in cabbage.

Cytoplasmic male sterility (CMS) is a maternally inherited trait producing abnormal pollen during anther development. To identify the critical genes and pathways that are involved in the sterility and to better understand the underlying mechanisms, cabbage anthers at different developmental stages were cytologically examined and the transcriptomes were analyzed in CMS line and its maintainer line using the next-generation sequencing (NGS) technology. Microscopy showed that anther development in the CMS line was abnormal in the tetrad stage and failed to produce fertile pollen. We obtained 55,663,594 and 54,801,384 raw transcriptome reads from the sterile and maintainer lines, respectively, and assembled these reads into 68,851 unigenes with an average size of 1028 bp. By using the fragments assigned per kilobase of target per million mapped reads (FPKM) method, 5592 differentially expressed genes were identified, consisting of 3403 up- and 2089 down-regulated genes. Furthermore, there were 1011 and 45 genes specifically expressed in the maintainer or sterile line, respectively. Gene Ontology (GO) functional annotation and enrichment analysis of metabolic pathways were performed to map and analyze the candidate genes that may be involved in male sterility. Expression of eighteen genes was examined using qRT-PCR and their expression patterns were found to be same as the sequencing data. A clear cytological difference exists between the sterile and maintainer lines. The differentially expressed genes are associated with carbohydrate and energy metabolisms, or encode transcription factors, heat shock proteins and other stress proteins. Identification of these candidate genes provides a comprehensive understanding of the mechanism underlying CMS in cabbage.

Human cytomegalovirus UL49 encodes an early, virion-associated protein essential for virus growth in human foreskin fibroblasts.

Despite recent results of deletion experiments showing that open reading frame (ORF) UL49 of human cytomegalovirus (HCMV) is essential, the expression, function and functional location of its encoded protein remain unknown. We generated an antibody specific for pUL49 to investigate the protein product encoded by the UL49 ORF and identified its function in HCMV-infected host foreskin fibroblasts. A bacterial artificial chromosome (BAC) of HCMV strain Towne (pRV-Towne) and the UL49-deleted mutant pRV-delUL49Towne were used to observe virus growth by plaque assay. Using a UL49-protein-binding antibody, we located pUL49 in the fibroblast cytoplasm. pUL49 exhibited expression kinetics resembling those of the class ß-2 proteins and was detected in the virion tegument. Following deletion of UL49 ORF, the virus failed to replicate, but it could be recovered by addition of pUL49 from pCDNA3.1 (+)-UL49. Our findings indicate that UL49 ORF is essential for HCMV replication in host foreskin fibroblasts.