GBSOT4 Enhances the Resistance of Gossypium barbadense to Fusarium oxysporum f. sp. vasinfectum (FOV) by Regulating the Content of Flavonoid.

Sulfotransferases (SOTs) (EC 2.8.2.-) are sulfate regulatory proteins in a variety of organisms that have been previously shown to be involved in regulating a variety of physiological and biological processes, such as growth, development, adaptation to land, stomatal closure, drought tolerance, and response to pathogen infection. However, there is a lack of comprehensive identification and systematic analysis of SOT in cotton, especially in G. barbadense. In this study, we used bioinformatics methods to analyze the structural characteristics, phylogenetic relationships, gene structure, expression patterns, evolutionary relationships, selection pressure and stress response of SOT gene family members in G. barbadense. In this study, a total of 241 SOT genes were identified in four cotton species, among which 74 SOT gene members were found in G. barbadense. According to the phylogenetic tree, 241 SOT protein sequences were divided into five distinct subfamilies. We also mapped the physical locations of these genes on chromosomes and visualized the structural information of SOT genes in G. barbadense. We also predicted the cis-acting elements of the SOT gene in G. barbadense, and we identified the repetitive types and collinearity analysis of SOT genes in four cotton species. We calculated the Ka/Ks ratio between homologous gene pairs to elucidate the selective pressure between SOT genes. Transcriptome data were used to explore the expression patterns of SOT genes, and then qRT-PCR was used to detect the expression patterns of GBSOT4, GBSOT17 and GBSOT33 under FOV stress. WGCNA (weighted gene co-expression network analysis) showed that GB_A01G0479 (GBSOT4) belonged to the MEblue module, which may regulate the resistance mechanism of G. barbadense to FOV through plant hormones, signal transduction and glutathione metabolism. In addition, we conducted a VIGS (virus-induced gene silencing) experiment on GBSOT4, and the results showed that after FOV inoculation, the plants with a silenced target gene had more serious leaf wilting, drying and cracking than the control group, and the disease index of the plants with the silenced target gene was significantly higher than that of the control group. This suggests that GBSOT4 may be involved in protecting the production of G. barbadense from FOV infection. Subsequent metabolomics analysis showed that some flavonoid metabolites, such as Eupatorin-5-methylether (3'-hydroxy-5,6,7,4'-tetramethoxyflavone, were accumulated in cotton plants in response to FOV infection.

The implication of chromosomal abnormalities in the surgical outcomes of Chinese pediatric patients with congenital heart disease.

Background: Copy number variations (CNVs) have been shown to be overrepresented in children with congenital heart disease (CHD). Genetic evaluation of CHD is currently underperformed in China. We sought to determine the occurrence of CNVs in CNV regions with disease-causing potential among a large cohort of Chinese pediatric CHD patients and investigate whether these CNVs could be the important critical modifiers of surgical intervention. Methods: CNVs screenings were performed in 1,762 Chinese children who underwent at least one cardiac surgery. CNV status at over 200 CNV locus with disease-causing potential was analyzed with a high-throughput ligation-dependent probe amplification (HLPA) assay. Results: We found 378 out of 1,762 samples (21.45%) to have at least one CNV and 2.38% of them were carrying multiple CNVs. The detection rates of ppCNVs (pathogenic and likely pathogenic CNVs) were 9.19% (162/1,762), significantly higher than that of the healthy Han Chinese individuals from The Database of Genomic Variants archive (9.19% vs. 3.63%; P = 0.0012). CHD cases with ppCNVs had a significantly higher proportion of complex surgeries compared to CHD patients with no ppCNVs (62.35% vs. 37.63%, P < 0.001). Duration of cardiopulmonary bypass and aortic cross clamp procedures were significantly longer in CHD cases with ppCNVs (all P < 0.05), while no group differences were identified for complications of surgery and one-month mortality after surgery. The detection rate of ppCNVs in the atrioventricular septal defect (AVSD) subgroup was significantly higher than that in other subgroups (23.10% vs. 9.70%, P = 0.002). Conclusions: CNV burden is an important contributor to Chinese children with CHD. Our study demonstrated the robustness and diagnostic efficiency of HLPA method in the genetic screening of CNVs in CHD patients.

Noninvasive fetal genotyping of single nucleotide variants and linkage analysis for prenatal diagnosis of monogenic disorders.

BACKGROUND: High-cost, time-consuming and complex processes of several current approaches limit the use of noninvasive prenatal diagnosis (NIPD) for monogenic disorders in clinical application. Thus, a more cost-effective and easily implementable approach is required. METHODS: We established a low-cost and convenient test to noninvasively deduce fetal genotypes of the mutation and single nucleotide polymorphisms (SNPs) loci by means of targeted amplification combined with deep sequencing of maternal genomic and plasma DNA. The sequential probability ratio test was performed to detect the allelic imbalance in maternal plasma. This method can be employed to directly examine familial pathogenic mutations in the fetal genome, as well as infer the inheritance of parental haplotypes through a group of selected SNPs linked to the pathogenic mutation. RESULTS: The fetal mutations in 17 families with different types of monogenic disorders including hemophilia A, von Willebrand disease type 3, Duchenne muscular dystrophy, hyper-IgM type 1, glutaric acidemia type I, Nagashima-type palmoplantar keratosis, and familial exudative vitreoretinopathy were identified in the study. The mutations included various forms: point mutations, gene inversion, deletions/insertions and duplication. The results of 12 families were verified by sequencing of amniotic fluid samples, the accuracy of the approach in fetal genotyping at the mutation and SNPs loci was 98.85% (172/174 loci), and the no-call rate was 28.98% (71/245 loci). The overall accuracy was 12/12 (100%). Moreover, the approach was successfully applied in plasma samples with a fetal fraction as low as 2.3%. CONCLUSIONS: We have shown in this study that the approach is a cost-effective, less time consuming and accurate method for NIPD of monogenic disorders.

HER2 copy number quantification in primary tumor and cell-free DNA provides additional prognostic information in HER2 positive early breast cancer.

BACKGROUND: The quantitative relationship between HER2 copy number and prognosis in HER2 positive adjuvant setting remain controversial, and few studies have focused on adjuvant setting to illustrate the potential clinical relevance of HER2 in cfDNA. Our study aim to develop a novel method in HER2 quantification and explore the relationship between HER2 copy number in primary tumors or cfDNA and prognosis in HER2 positive early breast cancer. METHODS: Two hundred and two patients with early breast cancer were prospectively included in a study where primary tumors, matching non-cancer breast tissue, corresponding plasma, and the plasma from 20 healthy volunteers were collected. Cox proportional hazard analysis was employed to determine the prognostic value of HER2 gene copy number in tissue and cfDNA. Tissue based nomograms and time-dependent decision curve analysis were used to evaluate the practicality of HER2 copy number stratification. RESULTS: HER2 amplification by CNVplex demonstrated a robust concordance with FISH (concordance 89.2%). A three-tiered system of tissue and a two-tiered system of cfDNA classification were shown to be independent prognostic factors. A tissue copy number-based nomogram was fitted and further evaluation revealed a good performance in discrimination (c statistic 0.801) and calibration. CONCLUSIONS: We first report CNVplex as a viable alternative for HER2 detection. Quantitative evaluation of HER2 presents tremendous potential for use in risk stratification. We also uncover the potential for using HER2 copy number in cfDNA as a biomarker for prognosis in a HER2 positive adjuvant setting.

A capillary electrophoresis-based multiplex PCR assay for expanded carrier screening in the eastern Han Chinese population.

Expanded carrier screening, a type of reproductive genetic testing for couples, has gained tremendous popularity for assessing the risk of passing on certain genetic conditions to offspring. Here, a carrier screening assay for 448 pathogenic variants was developed using capillary electrophoresis-based multiplex PCR technology. The capillary electrophoresis-based multiplex PCR assay achieved a sensitivity, specificity, and accuracy of 97.4%, 100%, and 99.6%, respectively, in detecting the specific variants. Among the 1915 couples (3830 individuals), 708 individuals (18.5%) were identified as carriers for at least one condition. Of the 708 carriers, 633 (89.4%) were heterozygous for one condition, 71 (10.0%) for two disorders, 3 (0.4%) for three disorders, and 1 (0.1%) for four disorders. Meanwhile, 30 (1.57%) couples were identified as at-risk couples. This study describes an inexpensive and effective method for expanded carrier screening. The simplicity and accuracy of this approach will facilitate the clinical implementation of expanded carrier screening.

Comprehensive copy number analysis of Y chromosome-linked loci for detection of structural variations and diagnosis of male infertility.

Infertility affects about 15% of heterosexual couples and male factors account for ~45-50% of clinical cases. Genetic factors play an important role in male infertility and thus we try to develop a cost-effective method for screening the genetic factors in male infertility. In our retrospective proof-of-concept study, we employed the high-throughput ligation-dependent probe amplification (HLPA) to examine the copy number by 115 genomic loci covering the Y chromosome, and 5 loci covering the X chromosome-specific region. We identified 8 sex chromosome aneuploid people from the low sperm concentration (LSC) group, and Y chromosome-specific microdeletion/duplications in 211 samples from the LSC group, and in 212 samples from the control group. 35 samples showed complete loss of AZFc (BPY2 to CDY1B deletion), which was not observed in controls. Nevertheless, a partial loss of AZFc (BPY2 to BPY2B deletion) was detected at comparable frequencies in both groups (68/211 vs. 108/212, respectively). And we further found structural variations in 28.6 and 26.9% samples from infertility and fertility groups. Moreover, we found that there were lower copy numbers for heterochromatic sequences in men with LSC. Especially, we reported that ultra-low relative copy number (RCN) (<0.5) type and low RCN (0.5 to <0.75) type in Yq12 were more often in the LSC group for the first time. Our results not only shed light on the potential role of low RCN in Yq12 in male infertility but also showed that HLPA can be a powerful and cost-effective tool for clinical screening in male infertility.

High-throughput sequencing-based microsatellite genotyping for polyploids to resolve allele dosage uncertainty and improve analyses of genetic diversity, structure and differentiation: A case study of the hexaploid Camellia oleifera.

Conventional microsatellite (simple sequence repeat, SSR) genotyping methods cannot accurately identify polyploid genotypes leading to allele dosage uncertainty, introducing biases in population genetic analysis. Here, a new SSR genotyping method was developed to directly infer accurate polyploid genotypes. The frequency distribution of SSR sequences was obtained based on deep-coverage high-throughput sequencing data. Corrections were performed accounting for the "stutter peak" and amplification efficiency of SSR sequences. Perl scripts and an online SSR genotyping tool "SSRSeq" were provided to process the sequencing data and output genotypes with corrected allele dosages. Hexaploid Camellia oleifera is the dominant woody oilseed crop in China. Understanding the geographical pattern of genetic variation in wild C. oleifera is essential for the conservation and utilization of genetic resources. Six wild C. oleifera populations were sampled across geographical ranges in subtropical evergreen broadleaf forests of China. Using 35 SSR markers, the high-throughput sequencing-based SSRSeq method was applied to obtain accurate hexaploid genotypes of wild C. oleifera. The results demonstrated that the new method could resolve allele dosage uncertainty and considerably improve genetic diversity, structure and differentiation analyses for polyploids. The genetic variation patterns of wild C. oleifera across geographical ranges agree with the "central-marginal hypothesis", stating that genetic diversity is high in the central population and declines from the central to the peripheral populations, and genetic differentiation increases from the centre to the periphery. This method and findings can facilitate the utilization of wild C. oleifera genetic resources for the breeding of cultivated C. oleifera.

A capillary electrophoresis-based variant hotspot genotyping method for rapid and reliable analysis of the phenylalanine hydroxylase gene in the Chinese Han population.

BACKGROUND AND AIMS: Hyperphenylalaninemia (HPA) is a common autosomal recessive disorder of phenylalanine metabolism, mainly caused by the deficiency of phenylalanine hydroxylase gene (PAH). A simple, fast, and accurate assay to achieve early diagnosis for children with HPA is required. MATERIALS AND METHODS: In the present study, we established a SNaPshot-based assay that allows the simultaneous genotyping of 96 hotspot variants in the PAH gene. First, 18 Chinese HPA patients were analyzed by next generation sequencing (NGS) and SNaPshot in parallel. Then, the SNaPshot assay was performed to analyze the mutational spectrum of the PAH in 4,276 individuals in Eastern China. RESULTS: A total of 36 variants in the PAH gene were successfully identified by NGS, while the SNaPshot assay identified 34 PAH variants in these patients. Thus, the SNaPshot assay achieved the sensitivity and specificity of 91.6% and 100.0%, respectively. Furthermore, the carrier rate was approximately 1 in 58 (1.73%) in 4,276 individuals, and c.728G > A was the most common variant. CONCLUSION: In summary, SNaPshot can accurately and rapidly detect PAH gene variants at a comparable performance and lower cost as compared with NGS. Our results suggest that SNaPshot may serve as a promising approach for a routine genetic test in clinical practice.

Identification of Chromosomal Abnormalities in Early Pregnancy Loss Using a High-Throughput Ligation-Dependent Probe Amplification-Based Assay.

Embryonic chromosomal abnormalities are the major cause of miscarriage. An accurate, rapid, and cheap method of chromosome analysis in miscarriage is warranted in clinical practice. Thus, a high-throughput ligation-dependent probe amplification (HLPA)-based method of detecting aneuploidies and copy number variations in miscarriage was developed. A total of 1060 cases of miscarriage were assessed. Each specimen was subjected to quantitative fluorescence (QF)-PCR/HLPA and chromosomal microarray analysis (CMA) in parallel. All 1060 samples were successfully analyzed using both methods; of these samples, 1.7% (18/1060) were identified as having significant maternal cell contamination. Among the remaining 1042 cases without significant maternal cell contamination, QF-PCR/HLPA reached a diagnostic yield of 59.6% (621/1042), which is comparable to the yield of 60.3% (628/1042) with CMA. Compared with CMA results, the sensitivity and specificity of QF-PCR/HLPA in the identification of total pathogenic chromosomal abnormalities were 98.9% and 100%, respectively. Furthermore, the overall prevalence of chromosomal abnormalities in cases of spontaneous abortion was not significantly different from that in cases of recurrent miscarriage (61.3% versus 58.5%). In summary, QF-PCR/HLPA rapidly and accurately identified chromosomal abnormalities at a comparable performance and lower cost as compared with CMA. Combining simplicity and accuracy with cost-effectiveness, QF-PCR/HLPA may serve as a promising approach to routine genetic testing in miscarriage in clinical practice.

Intronic (TTTGA)n insertion in SAMD12 also causes familial cortical myoclonic tremor with epilepsy.

BACKGROUND: Intronic (TTTCA)n insertions in the SAMD12, TNRC6A, and RAPGEF2 genes have been identified as causes of familial cortical myoclonic tremor with epilepsy. OBJECTIVE: To identify the cause of familial cortical myoclonic tremor with epilepsy pedigrees without (TTTCA)n insertions in SAMD12, TNRC6A, and RAPGEF2. METHODS: Repeat-primed polymerase chain reaction, long-range polymerase chain reaction, and Sanger sequencing were performed to identify the existence of a novel (TTTGA)n insertion. Targeted long-read sequencing was performed to confirm the accurate structure of the (TTTGA)n insertion. RESULTS: We identified a novel expanded intronic (TTTGA)n insertion at the same site as the previously reported (TTTCA)n insertion in SAMD12. This insertion cosegregated with familial cortical myoclonic tremor with epilepsy in 1 Chinese pedigree with no (TTTCA)n insertion. In the targeted long-read sequencing of 2 patients and 1 asymptomatic carrier in this pedigree, with 1 previously reported (TTTCA)n -insertion-carrying patient as a positive control, a respective total of 302, 159, 207, and 50 on-target subreads (predicated accuracy: ≥90%) spanning the target repeat expansion region were generated. These sequencing data revealed the accurate repeat expansion structures as (TTTTA)114-123 (TTTGA)108-116 in the pedigree and (TTTTA)38 (TTTCA)479 in (TTTCA)n -insertion-carrying patient. CONCLUSION: The targeted long-read sequencing helped us to elucidate the accurate structures of the (TTTGA)n and (TTTCA)n insertions. Our finding offers a novel possible cause for familial cortical myoclonic tremor with epilepsy and might shed light on the identification of genetic causes of this disease in pedigrees with no detected (TTTCA)n insertion in the reported causative genes. © 2019 International Parkinson and Movement Disorder Society.

Genetic Study on Small Insertions and Deletions in Psoriasis Reveals a Role in Complex Human Diseases.

Genetic studies based on single-nucleotide polymorphisms have provided valuable insights into the genetic architecture of complex diseases. However, a large fraction of heritability for most of these diseases remains unexplained, and the impact of small insertions and deletions (InDels) has been neglected. We performed a comprehensive screen on the exome sequence data of 1,326 genes using the SOAP-PopIndel method for InDels in 32,043 Chinese Han individuals and identified 29 unreported InDels within 25 susceptibility genes associated with psoriasis. Specifically, we identified 12 common, 9 low-frequency, and 8 rare InDels that explained approximately 1.29% of the heritability of psoriasis. Further analyses identified KIAA0319, RELN, NCAPG, ABO, AADACL2, LMAN1, FLG, HERC5, CCDC66, LEKR1, AFF3, ABCG2, ANXA7, SYTL2,GIPR, METTL1, and FYCO1 as unreported genes for psoriasis. In addition, identified InDels were associated with the following reported genes: IFIH1, ERAP1, ERAP2, LNPEP, UBLCP1, and STAT3; unreported independent associations for exonic InDels were found within GJB2 and ZNF816A. Our study enriched the genetic basis and pathogenesis of psoriasis and highlighted the non-negligible impact of InDels on complex human diseases.

Intronic pentanucleotide TTTCA repeat insertion in the SAMD12 gene causes familial cortical myoclonic tremor with epilepsy type 1.

Familial cortical myoclonic tremor with epilepsy is an autosomal dominant neurodegenerative disease, characterized by cortical tremor and epileptic seizures. Although four subtypes (types 1-4) mapped on different chromosomes (8q24, 2p11.1-q12.2, 5p15.31-p15.1 and 3q26.32-3q28) have been reported, the causative gene has not yet been identified. Here, we report the genetic study in a cohort of 20 Chinese pedigrees with familial cortical myoclonic tremor with epilepsy. Linkage and haplotype analysis in 11 pedigrees revealed maximum two-point logarithm of the odds (LOD) scores from 1.64 to 3.77 (LOD scores in five pedigrees were >3.0) in chromosomal region 8q24 and narrowed the candidate region to an interval of 4.9 Mb. Using whole-genome sequencing, long-range polymerase chain reaction and repeat-primed polymerase chain reaction, we identified an intronic pentanucleotide (TTTCA)n insertion in the SAMD12 gene as the cause, which co-segregated with the disease among the 11 pedigrees mapped on 8q24 and additional seven unmapped pedigrees. Only two pedigrees did not contain the (TTTCA)n insertion. Repeat-primed polymerase chain reaction revealed that the sizes of (TTTCA)n insertion in all affected members were larger than 105 repeats. The same pentanucleotide insertion (ATTTCATTTC)58 has been reported to form RNA foci resulting in neurotoxicity in spinocerebellar ataxia type 37, which suggests the similar pathogenic process in familial cortical myoclonic tremor with epilepsy type 1.

Germline Duplication of SNORA18L5 Increases Risk for HBV-related Hepatocellular Carcinoma by Altering Localization of Ribosomal Proteins and Decreasing Levels of p53.

BACKGROUND & AIMS: Single nucleotide polymorphisms could affect risk for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). We performed a germline copy number variation (CNV)-based genome-wide association study (GWAS) in populations of Chinese ancestry to search for germline CNVs that increase risk of HCC. METHODS: We conducted a CNV-based GWAS of 1583 HCC cases (persons with chronic HBV infection and HCC) and 1540 controls (persons with chronic HBV infection without HCC) in Chinese populations. Identified candidates were expressed in L-02, HepG2, or TP53-/- or wild-type HCT116 cells, and knocked down with short hairpin RNAs in HepG2, Bel-7402, and SMMC-7721 cells; proliferation, colony formation, and apoptosis were measured. Formation of xenograft tumors from cell lines was monitored in nude mice. Subcellular localization of ribosome proteins and levels or activity of p53 were investigated by co-immunoprecipitation, immunofluorescence, and immunoblot analyses. Levels of small nucleolar RNA H/ACA box 18-like 5 (SNORA18L5) were quantified by quantitative reverse transcription polymerase chain reaction. RESULTS: We identified a low-frequency duplication at chromosome 15q13.3 strongly associated with risk of HBV-related HCC (overall P = 3.17 × 10-8; odds ratio, 12.02). Copy numbers of the 15q13.3 duplication correlated with the expression of SNORA18L5 in liver tissues. Overexpression of SNORA18L5 increased HCC cell proliferation and growth of xenograft tumors in mice; knockdown reduced HCC proliferation and tumor growth. SNORA18L5 overexpression in HepG2 and SMMC-7721 cells inhibited p53-dependent cell cycle arrest and apoptosis. Overexpression of SNORA18L5 led to hyperactive ribosome biogenesis, increasing levels of mature 18S and 28S ribosomal RNAs and causing the ribosomal proteins RPL5 and RPL11 to stay in the nucleolus, which kept them from binding to MDM2. This resulted in increased MDM2-mediated ubiquitination and degradation of p53. Levels of SNORA18L5 were increased in HCC tissues compared with nontumor liver tissues and associated with shorter survival times of patients. CONCLUSIONS: In a CNV-based GWAS, we associated duplication at 15q13.3 with increased risk of HBV-related HCC. We found SNORA18L5 at this location to promote HCC cell proliferation and tumor growth in mice. SNORA18L5 increases ribosome biogenesis, facilitates ribosomal RNA maturation, and alters localization of RPL5 and RPL11, allowing for increased MDM2-mediated proteolysis of p53 and cell cycle arrest.

Noninvasive Prenatal Screening of Fetal Aneuploidy without Massively Parallel Sequencing.

BACKGROUND: Noninvasive prenatal screening (NIPS) using plasma cell-free DNA has gained tremendous popularity in the clinical assessment of fetal aneuploidy. Most, if not all, of these tests rely on complex and expensive massively parallel sequencing (MPS) techniques, hindering the use of NIPS as a common screening procedure. METHODS: We have developed and optimized an MPS-independent noninvasive genetic test that can rapidly detect fetal aneuploidy at considerably lower costs. We used the high-throughput ligation-dependent probe amplification (HLPA) assay with standard z score statistics to identify the minute copy number change of targeted chromosomal regions. HLPA was modified from multiplex ligation-dependent probe amplification to allow quantification of up to 200 genomic loci in a single multiplex PCR. As a proof of principle, we conducted Down syndrome screening in 1182 women with singleton pregnancies [maternal age (SD): 32.7 (4.6)] using whole-genome sequencing-based NIPS and our method. RESULTS: Nineteen fetuses with trisomy 21 were detected by both methods and confirmed by karyotyping of amniotic fluid. Overall, our method showed 100.0% sensitivity (19/19) and 99.7% specificity (1076/1079) in trisomy 21 screening, generating a positive predictive value of 86.4% (19/22) and a 7.1% (84/1182) no-call rate. CONCLUSIONS: Our technique potentially opens new avenues for the development of inexpensive, yet effective, prenatal aneuploidy tests. The simplicity and accuracy of this method make it a good candidate for clinical implementation as a standard screening procedure.

A copy number variation genotyping method for aneuploidy detection in spontaneous abortion specimens.

OBJECTIVE: Chromosomal abnormalities such as aneuploidy have been shown to be responsible for causing spontaneous abortion. Genetic evaluation of abortions is currently underperformed. Screening for aneuploidy in the products of conception can help determine the etiology. We designed a high-throughput ligation-dependent probe amplification (HLPA) assay to examine aneuploidy of 24 chromosomes in miscarriage tissues and aimed to validate the performance of this technique. METHODS: We carried out aneuploidy screening in 98 fetal tissue samples collected from female subjects with singleton pregnancies who experienced spontaneous abortion. The mean maternal age was 31.6 years (range: 24-43), and the mean gestational age was 10.2 weeks (range: 4.6-14.1). HLPA was performed in parallel with array comparative genomic hybridization, which is the gold standard for aneuploidy detection in clinical practices. The results from the two platforms were compared. RESULTS: Forty-nine out of ninety-eight samples were found to be aneuploid. HLPA showed concordance with array comparative genomic hybridization in diagnosing aneuploidy. CONCLUSION: High-throughput ligation-dependent probe amplification is a rapid and accurate method for aneuploidy detection. It can be used as a cost-effective screening procedure in clinical spontaneous abortions. © 2016 John Wiley & Sons, Ltd.

Folate deficiency facilitates recruitment of upstream binding factor to hot spots of DNA double-strand breaks of rRNA genes and promotes its transcription.

The biogenesis of ribosomes in vivo is an essential process for cellular functions. Transcription of ribosomal RNA (rRNA) genes is the rate-limiting step in ribosome biogenesis controlled by environmental conditions. Here, we investigated the role of folate antagonist on changes of DNA double-strand breaks (DSBs) landscape in mouse embryonic stem cells. A significant DSB enhancement was detected in the genome of these cells and a large majority of these DSBs were found in rRNA genes. Furthermore, spontaneous DSBs in cells under folate deficiency conditions were located exclusively within the rRNA gene units, representing a H3K4me1 hallmark. Enrichment H3K4me1 at the hot spots of DSB regions enhanced the recruitment of upstream binding factor (UBF) to rRNA genes, resulting in the increment of rRNA genes transcription. Supplement of folate resulted in a restored UBF binding across DNA breakage sites of rRNA genes, and normal rRNA gene transcription. In samples from neural tube defects (NTDs) with low folate level, up-regulation of rRNA gene transcription was observed, along with aberrant UBF level. Our results present a new view by which alterations in folate levels affects DNA breakage through epigenetic control leading to the regulation of rRNA gene transcription during the early stage of development.

Familial Hypercholesterolemia Phenotype in Chinese Patients Undergoing Coronary Angiography.

OBJECTIVE: Familial hypercholesterolemia (FH) is characterized by an elevated low-density lipoprotein cholesterol and increased risk of premature coronary artery disease. However, the general picture and mutational spectrum of FH in China are far from recognized, representing a missed opportunity for the investigation. APPROACH AND RESULTS: A total of 8050 patients undergoing coronary angiography were enrolled. The diagnosis of clinical FH was made using Dutch Lipid Clinic Network criteria, and the information of relatives was obtained by inquiring for the probands or from their own medical records of certain clinics/hospitals. Molecular analysis of FH was performed using target exome sequencing in LDLR (low-density lipoprotein cholesterol receptor gene), APOB (apolipoprotein B gene), and PCSK9 (proprotein convertase subtilisin/kexin type 9 gene). As a result, 3.5% of the patients with definite/probable FH phenotype (definite 1.0% and probable 2.5%) were identified. Women FH had fewer premature coronary artery disease (women <60, or men <55 years of age) when compared with men FH (70.6% versus 82.7%; P<0.001), whereas angiographic extension of coronary artery disease was significantly increased with FH diagnosis in both men and women (P<0.001). Patterns of medication use in definite/probable FH were as follows: nontreated, 20.6%; low intensity, 6.0%; moderate intensity, 68.3%; and high intensity, 5.0%. However, none of them had achieved the low-density lipoprotein cholesterol <100 mg/dL. Additionally, mutational analysis was performed in 245 definite/probable FH cases, and risk variants were identified in 115 patients, giving a detection rate of 46.9%. CONCLUSIONS: We showed firsthand a common identification but poor treatment of patients with FH phenotype in Chinese coronary angiography patients. Genetic data in our FH cases might contribute to update the frequency and spectrum of Chinese FH scenarios.

Head-and-neck squamous cell carcinoma risk in smokers: no association detected between phenotype and AHR, CYP1A1, CYP1A2, or CYP1B1 genotype.

BACKGROUND: Head-and-neck squamous cell carcinoma (HNSCC) differs between smokers and nonsmokers in etiology and clinical presentation. Because of demonstrated unequivocal involvement in smoking-induced cancer in laboratory animals, four candidate genes--AHR, CYP1A1, CYP1A2, and CYP1B1--were selected for a clinical genotype-phenotype association study of HNSCC risk in smokers. Thirty-six single-nucleotide variants (mostly tag-SNPs) within and near these four genes [16 (AHR), 4 (CYP1A1), 4 (CYP1A2), and 12 (CYP1B1)] were chosen. METHODS: Extreme discordant phenotype (EDP) method of analysis was used to increase statistical power. HNSCC patients--having smoked 1-40 cigarette pack-years--represented the "highly-sensitive" (HS) population; heavy smokers having smoked ≥80 cigarette-pack-years without any type of cancer comprised the "highly-resistant" (HR) group. The vast majority of smokers were intermediate and discarded from consideration. Statistical tests were performed on N = 112 HS and N = 99 HR DNA samples from whole blood. CONCLUSIONS: Among the four genes and flanking regions--one haploblock, ACTTGATC in the 5' portion of CYP1B1, retained statistical significance after 100,000 permutations (P = 0.0042); among our study population, this haploblock was found in 36.4% of African-American, but only 1.49% of Caucasian, HNSCC chromosomes. Interestingly, in the 1000 Genomes Project database, frequency of this haplotype (in 1322 African and 1006 Caucasian chromosomes) is 0.356 and 0.003, respectively. This study represents an excellent example of "spurious association by population stratification". Considering the cohort size, we therefore conclude that the variant alleles chosen for these four genes, alone or in combinations, are not statistically significantly associated with risk of cigarette-smoking-induced HNSCC.

AccuCopy quantification combined with pre-amplification of long-distance PCR for fast analysis of intron 22 inversion in haemophilia A.

BACKGROUND: To develop a digitalized intron 22 inversion (Inv22) detection in patients with severe haemophilia A. METHODS: The design included two tests: A genotyping test included two multiplex pre-amplification of LD-PCR (PLP) with two combinations of five primers to amplify wild-type and chimeric int22h alleles; a carrier mosaicism test was similar to the genotyping test except only amplification of chimeric int22h alleles by removing one primer from each of two combinations. AccuCopy detection was used to quantify PLP products. RESULTS: PLP product patterns in the genotyping test allowed identifying all known Inv22. Quantitative patterns accurately represented the product patterns. The results of 164 samples detected by the genotyping test were consistent with those obtained by LD-PCR detection. Limit of detection (LOD) of the carrier mosaicism test was at least 2% of heterozygous cells with Inv22. Performing the test in two obligate mothers with negative Inv22 from two sporadic pedigrees mosaic rates of blood and hair root of the mother from pedigree 1 were 8.3% and >20%, respectively and negative results were obtained in pedigree 2. CONCLUSIONS: AccuCopy quantification combined with PLP (AQ-PLP) method was confirmed to be rapid and reliable for genotyping Inv22 and highly sensitive to carrier mosaicism detection.