Analysis of genotype-phenotype correlation in patients with α-thalassemia from Fujian province, Southeastern China

Background

There is a high carrying rate of α‐thalassemia in Fujian province. However, there are few large‐scale studies on the correlation between genotype and phenotype in Fujian province. The purpose of this study was to analyze the phenotype and genotype in a cohort of 2923 patients with α‐thalassemia in Fujian province, so as to provide reference data for screening and diagnosis of α‐thalassemia in Fujian province.

Methods

The genotype of α‐thalassemia was detected by PCR reverse dot blot assay, gap‐PCR, single PCR, nested PCR, and sequencing. Clinical and hematological indices of 2923 patients were collected, and the correlation between genotype and phenotype was analyzed.

Results

Among 10,350 patients, 2923 cases were found with α‐thalassemia, with a detection rate of 28.24%. Among them, ‐‐^SEA/αα was the most common genotype, accounting for 64.80%. In addition, rare α‐thalassemia genotypes were detected in Fujian province, including ‐‐^THAI/αα (0.41%), HKαα/‐‐^SEA (0.03%), and the novel α‐thalassemia gene mutation CD5 (GCC>ACC) (HGVS named HBA1: c.16G>A) (0.03%). Patients with deletional genotypes of α‐thalassemia were found to have higher RBC and lower Hb, MCV, MCH, and HbA2 than patients with non‐deletional genotypes of α‐thalassemia (p < 0.05).

Conclusion

The clinical phenotype of α‐thalassemia is influenced by molecular mechanisms. HBA1: c.16G>A mutation is a novel mutation that was first reported in Fujian province, which enriches the human hemoglobin mutation spectrum.

Successful Management of a Young Athlete with Type 2 Long QT Syndrome by Genotype-specific Risk Stratification and Bridging Therapy with a Wearable Cardioverter Defibrillator

We herein report a 14-year-old boy with repetitive nocturnal syncope related to medication-refractory long QT syndrome (LQTS). Although the use of an implantable cardioverter-defibrillator (ICD) was inevitable to prevent sudden cardiac death, he refused immediate implantation in order to play in a baseball competition six weeks away. Given his genetic diagnosis of type 2 LQTS, which is associated with cardiac events unrelated to exercise, we prescribed a wearable cardioverter defibrillator (WCD) to be donned at night, without limiting his exercise participation. An ICD was implanted after the competition. We successfully performed the preplanned treatment while maximizing the patient's quality-of-life with a WCD and genotype-specific risk stratification.

Combinations of Ghd7, Ghd8, and Hd1 determine strong heterosis of commercial rice hybrids in diverse ecological regions

Heterosis of grain yield is closely associated with heading date in crops. Gene combinations of the major heading date genes Ghd7, Ghd8, and Hd1 play important roles in enhancing grain yield and adaptation to ecological regions in rice. However, the predominant three-gene combinations for a specific ecological region remain unclear in both three-line and two-line hybrids. In this study, we sequenced these three genes of 50 cytoplasmic male sterile/maintainer lines, 31 photo-thermo-sensitive genic male sterile lines, and 109 restorer lines. Sequence analysis showed that hybrids carrying strong functional alleles of Ghd7 and Hd1 and non-functional Ghd8 are predominant in three-line hybrids and are recommended for rice production in the subtropics around 30°N/S. Hybrids carrying strong functional Ghd7 and Ghd8 and non-functional Hd1 are predominant in two-line hybrids and are recommended for low latitude areas around 23.5°N/S rich in photothermal resources. Hybrids carrying strong functional Ghd7 and Ghd8 and functional Hd1 were not identified in commercial hybrids in the middle and lower reaches of the Yangtze River, but they have high yield potential in tropical regions because they have the strongest photoperiod sensitivity. Based on these findings, two genic sterile lines, Xiangling 628S and C815S, whose hybrids often head very late, were diagnosed with these three genes, and Hd1 was targeted to be knocked out in Xiangling 628S and replaced with hd1 in C815S. The hybrids developed from both modified sterile lines in turn had appropriate heading dates and significantly improved grain yield. This study provides new insights for breeding design to develop hybrids for various regions.

Current Study of the Detection and Treatment Targets of Spinal Tuberculosis

Spinal tuberculosis is a common manifestation of extrapulmonary tuberculosis and osteoarticular tuberculosis. Common clinical manifestations include constitutional symptoms, back pain, spinal tenderness, paraplegia, and spinal deformities. They are the common causes of paralysis and could increase the mortality in patients. Most cases of spinal tuberculosis remaining undiagnosed, and early clinical symptoms and imaging manifestations lack specificity, which explained the reason why it is difficult to identify from atypical spinal metastases, brucellosis and other diseases. The rate of missed diagnosis and misdiagnosis for spinal tuberculosis is high. If spinal tuberculosis diagnostic targets could be early detected, the therapeutic targets can be effectively treated, which can not only control the progress of the disease and shorten the course of treatment, but also reduce the economic pressure and avoid spinal deformity. Therefore, early diagnosis should be our focus. Comprehensive use of a variety of diagnostic targets can improve the early diagnosis rate of spinal tuberculosis. Here, we review the progress of laboratory, imaging and gene detection in the diagnosis of spinal tuberculosis in recent years.

A Designed Experiment: Polymorphism Analysis of Angiotensin-Converting Enzyme Gene from Human Buccal Epithelial Cells

For medical students, we combine the laboratory practice with clinical applications by developing biochemical and molecular biology experiments. In this experiment, students first collect their own buccal epithelial cells by a noninvasive mouthwash method. Then, they extract genomic DNA and perform polymerase chain reaction (PCR) to amplify angiotensin-converting enzyme (ACE) gene using genomic DNA as a template. Finally, the polymorphism of ACE gene is observed by electrophoresis. Students not only learn the techniques but also acquire knowledge of the ACE gene polymorphism. By establishing the relationship among ACE polymorphism and high blood pressure and myocardial hypertrophy, students should be able to understand the gene polymorphism and its association with susceptibility to disease. This laboratory practice teaching can also stimulate desire to do scientific research. Experimental results from many individuals can help us determine and analyze the fractions of ACE gene types in Chinese cohorts. Such an experiment strongly activates students and provides a solid foundation for the medical students' future research and clinical application. © 2019 International Union of Biochemistry and Molecular Biology, 47(2): 168-174, 2019.

Application of Next-Generation Sequencing Following Tandem Mass Spectrometry to Expand Newborn Screening for Inborn Errors of Metabolism: A Multicenter Study

This study explored the effectiveness of expanding newborn screening (NBS) by tandem mass spectrometry (TMS) and gene diagnosis by next-generation sequencing (NGS). First, we described the characteristics of gene variants in Jiangsu Province. We collected clinical data from three NBS centers. All infants followed a unified screening and diagnosis process. After obtaining informed consent, dried blood spots (DBSs) were collected and analyzed by TMS. If the results fell outside of the cut-off value, repeat analysis was performed. If the re-test results remained abnormal, the infant was recalled for further assessment. We performed targeted sequencing using the extended edition panel of inborn errors of metabolism (IEM) to detect 306 genes using the Illumina HiSeq 2500 platform. A total of 536,008 babies underwent NBS by TMS in three NBS centres. In total, 194 cases were eventually diagnosed with various types of inherited metabolic diseases, with an overall incidence of 1/2763. There were 23 types of diseases, including ten amino acid disorders (43.5%), eight organic acidaemias (34.8%) and five fatty acid oxidation defects (21.7%). In these infants, we clearly identified variants of disease-causing genes by next-generation sequencing (NGS). Most had two variants and others had one or three variants: 88% of gene variants were heterozygous and 12% were homozygous. There is a certain incidence of IEM in Jiangsu Province and it is necessary to carry out screening for 27 diseases. Meanwhile, NGS combined with TMS offers an enhanced plan for NBS for IEM.

[The clinical application of gene diagnosis and genetic counseling on hereditary hearing loss]

Objective:To summarize the clinic procedure and experience about gene diagnosis and genetic counseling on hereditary hearing loss, and explore the strategy and principle about gene diagnosis and genetic counseling on hereditary hearing loss.Method:A retrospective analysis was used on the clinical data of 151 cases who aim at genetic counseling. The all cases were divided into 5 groups according to the purpose of genetic counseling, such as the occurrence risk of hearing loss, the etiological analysis, the choice of the intervention way, the examination guidance, the prevention of hearing loss and the usage requirement of Aminogly cosides drugs. The counseling procedure includes the investigation of the etiology and family history, drawing the family pedigree, general physical examination, auditory examination and genetic analysis. Sanger sequencing analysis and/or Targeted nextgeneration sequencing was utilized to detect the deaf-gene mutations. At last, the genetic counseling, fertility guidance and prenatal diagnosis will be made on the basis of the results of gene detection. Result:There are 33 newborns who did not pass the deafgene screening, 9 of them could be diagnosed definitely as hereditary hearing loss, and the other 24 were the carriers of deafgene mutation. Eighty of 104 deaf patients were diagnosed definitely as hereditary hearing loss and the related gene mutation was found. Six objects in the 10 patients with auditory neuropathy are diagnosed as OTOF or SLC17A8 gene mutations before cochlear implantation. Three of 7 reproductive age objects who had family history were recessive deaf-gene carriers, 2 of them carried the same target gene with the mate who receive our fertility guidance and prenatal diagnose. The other 1 object carried the dominant genetic mutation(incomplete dominant heredity). There were 4 pregnant women who did not pass the deaf-gene screening, 1 of them carry the same target gene with the mate. The populations who want to use Aminoglycosides drugs were not diagnosed as carrying any related mitochondrial gene mutation. We carried out the genetic counseling according to the results of gens detection and clinical phenotype.Conclusion:Genetic counseling is based on the different purpose. The analysis of gene diagnosis should be considered to combine with the clinical phenotype. The principle of choosing the objects to make a gene diagnosis includes: ①the all deaf-genes sequencing was applied for the deaf patients. ② the screening target gene sequencing was used for the newborns who did not pass the deaf-gene screening and the mate whose pregnant wife did not pass the deafgene screening. ③the specific target gene sequencing could be used for the patients who has a clear family history or specific phenotype.

Genetic diagnosis for X-linked hypohidrotic ectodermal dysplasia family with a novel Ectodysplasin A gene mutation

AIM

To make a gene diagnosis for a family with Ectodysplasin A (EDA) gene mutation as well as prenatal diagnosis, and report a novel EDA gene mutation.

METHODS

All coding sequences and flanking sequences of EDA gene were analyzed by Sanger sequencing in the proband, and then, according to EDA gene mutation in the proband, the EDA gene sequencing was performed on the family members. Based on the results above, the pathogenic mutation in EDA gene was finally identified, which was used for making prenatal diagnosis.

RESULTS

Sanger sequencing revealed c.302_303delCC [p.Pro101HisfsX11] mutation in EDA gene of the proband. This mutation induced EDA gene frame shift mutation which led to early termination of EDA gene translation because there was a termination codon TAA at the 11th codon behind the mutational site. Heterozygous deletion mutation (CC/--) at this locus was observed in the proband's mother and proband's grandmother, but the proband's aunt had no mutation at this locus. The analyses of amniotic fluid samples indicated negative sex-determining region on Y (SRY), and c.302_303delCC heterozygous deletion mutation.

CONCLUSION

We identified a pathogenetic mutation in EDA gene for the X-linked hypohidrotic ectodermal dysplasia family, made a prenatal diagnosis for the female carrier, and reported a novel EDA gene mutation.

Reduced expression of circRNA hsa_circ_0003159 in gastric cancer and its clinical significance

BACKGROUND

Circular RNAs (circRNAs) play a crucial role in the occurrence of several diseases including cancers. However, little is known about circRNAs' diagnostic values for gastric cancer, one of the worldwide most common diseases of mortality.

METHODS

The hsa_circ_0003159 levels in 108 paired gastric cancer tissues and adjacent non-tumorous tissues from surgical patients with gastric cancer were first detected by real-time quantitative reverse transcription-polymerase chain reaction. Then, the relationships between hsa_circ_0003159 expression levels in gastric cancer tissues and the clinicopathological factors of patients with gastric cancer were analyzed. Finally, its diagnostic value was evaluated through the receiver operating characteristic curve.

RESULTS

Compared with paired adjacent non-tumorous tissues, hsa_circ_0003159 expression was significantly down-regulated in gastric cancer tissues. What is more, we found that hsa_circ_0003159 expression levels were significantly negatively associated with gender, distal metastasis, and tumor-node-metastasis stage.

CONCLUSIONS

All of the results suggest that hsa_circ_0003159 may be a potential cancer marker of patients with gastric cancer.

Different types of glomerulonephritis associated with the dysregulation of the complement alternative pathway in 2 brothers: A case report

RATIONALE

C3 glomerulonephritis (C3GN) and complement-mediated hemolytic uremic syndrome (HUS) both result from the abnormal regulation of the complement system. A significant number of patients with C3GN or complement-mediated HUS have mutations of more than 1 complement protein. This discovery has had a major impact on identifying the underlying cause of familial C3GN or complement-mediated HUS.

PATIENT CONCERNS

We report the cases of 2 brothers (herein referred to as patient II-1 and patient II-9), both with complement disorders that differed in their clinical and genetic features.

DIAGNOSES

Patient II-1 clinically presented with nephrotic syndrome and acute kidney injury and pathologically presented with C3GN combined with thrombotic microangiopathy (TMA) and subacute tubulointerstitial nephritis. Meanwhile, patient II-9 clinically presented with HUS and pathologically presented with TMA combined with acute severe tubular injury.

INTERVENTIONS

Screenings for genetic mutations contributed to complement system dysregulation were performed on patient II-1.

OUTCOMES

The genome sequencing identified that patient II-1 had a heterozygous mutation in the C3 gene (c.C1774T/p.R592W). Nine other relatives of the brothers were checked for this C3 mutation and only the daughter of patient II-1 (herein referred to as patient III-2) carried it, but so far, she does not have any clinical manifestations of kidney disease.

LESSIONS

Family members with a dysregulation of the complement alternative pathway may differ in its clinical and genetic features.

Genetic characteristics of the couple with non-syndromic sensorineural hearing loss and fertility guidance

PURPOSE

We aim to report a genetic testing and fertility guidance for the deaf through analyzing pedigree and molecular genetic characteristics of the couple who have non-syndromic sensorineural hearing loss (NSHL).

METHODS

One of hospitalized congenial deaf couple and family members were included in this study. The wife was twin pregnant woman and her gestational age was 31(+5) pregnant weeks. The DNA was extracted from peripheral blood and umbilical vein blood, respectively. Mutation screening of common deafness genes was performed in pregnant women and other family members. Nine common mutations in four major deafness genes, GJB2 (35delG, 176del16, 235delC, 299delAT), GjB3 (C538T), SLC26A4 (IVS7-2A>G, A2168G) and Mitochondrial 12S rRNA (A1555G, C1494T), were detected simultaneously with a microarray based method. SLC26A4 whole genome sequencing was carried out for the results of the DNA microarray. According to the test results, the couple chose abortion termination of pregnancy twins, and after one year obtained singleton pregnancy by artificial insemination by donor (AID). In week 16 of pregnancy, amniocentesis had been done to collect fetal somatic cell and extract DNA, and then the above tests had been repeated.

RESULTS

The couple had SLC26A4 combined heterozygous mutation. Both parents had SLC26A4 single heterozygous mutation. Twin fetuses had SLC26A4 combined heterozygous mutation. The probability of naturally being pregnant and bearing deaf children for the pregnant women was 100%. Fetus obtained by AID had SLC26A4 single heterozygous mutation. After the birth of the baby, her hearing has been normal.

CONCLUSIONS

To reduce children with congenital deafness, screening high mutation sites by microarray, combined with pedigree analysis and gene sequencing is effective, and should be used as a routine inspection item for the deaf before marriage and pregnancy. On the basis of genetic testing for the couple with hearing loss, human assisted reproductive technology is a viable option to avoid the birth of infant with hereditary deafness.