RDH12-associated retinal degeneration caused by a homozygous pathogenic variant of 146C>T and literature review

AIM:To describe the clinical,electrophysiological,and genetic features of an unusual case with an RDH12 homozygous pathogenic variant and reviewed the characteristics of the patients reported with the same variant.METHODS:The patient underwent a complete ophthalmologic examination including best-corrected visual acuity,anterior segment and dilated fundus,visual field,spectral-domain optical coherence tomography(OCT)and electroretinogram(ERG).The retinal disease panel genes were sequenced through chip capture high-throughput sequencing and Sanger sequencing was used to confirm the result.Then we reviewed the characteristics of the patients reported with the same variant.RESULTS:A 30-year male presented with severe early retinal degeneration who complained night blindness,decreased visual acuity,vitreous floaters and amaurosis fugax.The best corrected vision was 0.04 OD and 0.12 OS,respectively.The fundus photo and OCT showed bilateral macular atrophy but larger areas of macular atrophy in the left eye.Autofluorescence shows bilateral symmetrical hypo-autofluorescence.ERG revealed that the amplitudes of a-and b-wave were severely decreased.Multifocal ERG showed decreased amplitudes in the local macular area.A homozygous missense variant c.146C>T(chr14:68191267)was found.The clinical characteristics of a total of 13 patients reported with the same pathologic variant varied.CONCLUSION:An unusual patient with a homozygous pathogenic variant in the c.146C>T of RDH12 which causes late-onset and asymmetric retinal degeneration are reported.The clinical manifestations of the patient with multimodal retinal imaging and functional examinations have enriched our understanding of this disease.

Iron Metabolism Abnormalities in Children with Homozygous Sickle Cell Disease in Brazzaville

Introduction: Sickle cell disease is the most common genetic disease in the world, particularly in sub-Saharan Africa. It is a protean condition with multiple complications including disturbed iron metabolism. Objectives: To determine the prevalence of iron metabolism abnormalities in children with homozygous sickle cell disease, to describe the epidemiological, clinical and paraclinical characteristics of children with these abnormalities and to identify associated factors. Patients and Methods: This was a cross-sectional analytical study conducted over 9 months in the mother-child consultation unit of the Brazzaville University Hospital, the National Reference Centre for Sickle Cell Disease and the paediatric department of the Blanche Gomes mother-child hospital. It concerned children aged between 3 months and 15 years followed up for homozygous sickle cell disease. The study was based on a haemogram, iron metabolism test, LDH, transaminases and CRP. Results: The overall prevalence of iron metabolism abnomalities was 40.7%. Of the 145 children included, 35.9% had iron overload and 4.8% iron deficiency. Iron overload was associated with infections, undernutrition, iron supplementation and number of blood transfusions. Iron deficiency was not significantly associated with any factor but recurrent infections were relatively more frequent. Conclusion: Abnormalities of iron metabolism in sickle cell patients are relatively frequent, which justifies monitoring during follow-up for early detection and better management. .

Development of homozygous tetraploid potato and whole genome doubling-induced the enrichment of H3K27ac and potentially enhanced resistance to cold-induced sweetening in tubers

Polyploid plants typically display advantages on some agronomically important traits over their diploid counterparts.Extensive studies have shown genetic,transcriptomic,and epigenetic dynamics upon polyploidization in multiple plant species.However,few studies have unveiled those alternations imposed only by ploidy level,without any interference from heterozygosity.Cultivated potato is highly heterozygous.Thus,in this study,we developed two homozygous autotetraploid lines and one homozygous diploid line in parallel from a homozygous diploid potato.We confirmed their ploidy levels using chloroplast counting and karyotyping.Oligo-FISH and genome re-sequencing validated that these potato lines are nearly homozygous.We investigated variations in phenotypes,transcription,and histone modifications between two ploidies.Both autotetraploid lines produced larger but fewer tubers than the diploid line.Interestingly,each autotetraploid line displayed ploidy-related differential expression for various genes.We also discovered a genomewide enrichment of H3K27ac in genic regions upon whole-genome doubling(WGD).However,such enrichment was not associated with the differential gene expression between two ploidies.The tetraploid lines may exhibit better resistance to cold-induced sweetening(CIS)than the diploid line in tubers,potentially regulated through the expression of CIS-related key genes,which seems to be associated with the levels of H3K4me3 in cold-stored tubers.These findings will help to understand the impacts of autotetraploidization on dynamics of phenotypes,transcription,and histone modifications,as well as on CIS-related genes in response to cold storage.

Correlation between Pubertal Delay in Adolescents with Homozygous Sickle Cell Disease and Socio-Demographic, Clinical Factors

Introduction: Pubertal development is a process leading to the acquisition of reproductive capacities. Among the factors that inhibit pubertal development are chronic diseases including sickle cell anemia, which is a public health problem. Objectives: Describe the sociodemographic and clinical characteristics of adolescents with sickle cell disease. Report the prevalence of abnormalities of pubertal development. Identify associated factors that delay pubertal development. Patients and Methods: This was a multicenter analytical cross-sectional study over 7 months at the National Reference Center for Sickle Cell Disease and, at the Brazzaville University Hospital. It concerned adolescents with sickle cell disease aged between 10 to 19 years. The study focused on the sociodemographic characteristics of adolescents, the natural history of sickle cell anemia and the evaluation of secondary sexual characteristics using the Tanner classification. Nutritional status was assessed by calculating body mass index (BMI) and height/age and weight/age ratios. Results: Of the 347 adolescents included, the average age of the adolescents was 15.1 ± 2.5 years, 56.5% had normal puberty, 42.6% had delayed puberty and 0.9% had impuberty. The associated factors were under-nutrition with less than 3 meals/day (p = 0.0000), social status with more marked pubertal delay in orphans (p = 0.00127), more than 5 hospitalizations per year (p = 0.0013), pubertal delay was statistically significant in adolescents who had more than 3 vaso-occlusive crises (p = 0.0000), and those who had more than 5 blood transfusions since the discovery of the disease (p = 0.0127). Conclusion: The factors that hinder pubertal development in sickle cell patients are intrinsic (sickle cell anemia with its complications) and extrinsic (environmental: diet, social status). The appearance of secondary sexual characteristics is delayed on average by two years compared to the general population.

Homozygous Hemoglobinosis CC: A Series of 3 Cases and a Review of the Literature

Hemoglobinosis C occurs mainly in Africa and America with a high frequency in West Africa. In Senegal, homozygous hemoglobinopathy CC constitutes a very rare profile of which only 3 cases are followed in the clinical hematology department of Dakar. The 1st case is a 49-year-old female patient, with notion of 1st degree consanguinity, and a long history of abdominal pain who presented a poorly tolerated anemic syndrome and splenomegaly. The biological assessment showed moderate anemia (7.6 g/dL) with microcytic hypochromia and a CC profile (HbC = 99.2%;HbA2 = 0.8%) on hemoglobin electrophoresis. The second case was a 22-year-old female patient with a notion of 2nd degree consanguinity who presented a Chauffard triad. The haemogram showed mild anaemia (11 g/dL), microcytic and hypochromic. Hemoglobin electrophoresis confirmed a CC profile (HbC = 95.3%;HbA2 = 4.7%). The third patient was 27 years old, with a history of diffuse abdominal pain and 2nd degree consanguinity. The haemogram and haemoglobin electrophoresis confirmed the CC profile (HbC = 94.6%;HbA2 = 5.4%). The negativity of the Emmel test in front of this presentation suggestive of sickle cell disease means that this type of hemoglobinopathy is diagnosed late in our regions. We therefore recommend the systematic performance of hemoglobin electrophoresis in the presence of any chronic hemolytic anemia.

Hearing analysis in heterozygous and homozygous klotho gene deficient mice

Objective: To understand the crucial role of the klotho gene in hearing development in mouse models.Methods: PCR was used to identify CBA mice with different genotypes, i.e. WT, heterozygous(klotho +/-)or homozygous(klotho-/-). Mice phenotype and weight were recorded postnatal 25 days(P-25) and auditory brainstem responses(ABR) were used to determine auditory function at P-60.Results: klotho-/-mice tended to have smaller size, lighter weight and higher ABR thresholds at P-60,showing early onset age-related hearing loss(ARHL).Conclusion: Heterozygous and homozygous klotho deficient mice exhibit different degrees of hearing loss at young age, with homozygous mice(klotho-/-) showing more severe hearing loss. Our results indicate that persisted expression of klotho protein in the inner ear may potentially delay the onset of ARHL and play an important role in the protection of auditory function.

Minor modifications in obtainable Arabidopsis floral dip method enhances transformation efficiency and production of homozygous transgenic lines harboring a single copy of transgene

Many researchers have developed various methods for in-planta or floral dip transformation of Arabidopsis thaliana, one of the simple protocol and widely used to produce transgenic Arabidopsis. As the efficiency and ease of getting a transformant is very much time consuming effort and less number of the transformants people get, we have developed a little modified transformation protocol to avoid the disparities. Four types of inoculums (inoculum1, inoculum2, inoculum3 and inoculum4) were used to check the transformation efficiency out of which Inoculum3 showed the highest rate of transformation among the four types. 0.07% Twin-20 also acts in same manner as silwet L-77 to increase the rate of transformation efficiency and glucose instead of sucrose can be used in inoculum to transform Arabidopsis. After vacuum infiltration keeping the Agrobacterium infected plants for 7-8 hrs horizontally in low light at 280C temperature condition, considered best to get an increased number of transformed seeds. Modified protocol produced ~12-14% increase in transformants. Selection pots (kanamycin supplemented soil filled pots) in place of selection plates (Kanamycin supplemented Murashige and Skoog agar plates) proved beneficial as no MS medium and no aseptic condition is required for selection of transformed plants. This increase in transformation efficiency consequently increased the percentage of homozygous and single copied stable transgenic lines.

Selection of Homozygous Cotton Lines Transformed with Two Insect-Resistant Genes

A plant expression vector containing a chimeric Bt29K gene coding for the activated Cry1Ac protein and the arrowhead proteinase inhibitior gene API B were introduced into the cotton cultivar Jihe321 mediated by Agrobactertium tumefaciens. Based on the results of kanamycin resistant testing, PCR detection for both foreign genes and insect bioassay using Heliethis armigera , nine transgenic homozygous cotton lines with insect resistance of more than 90% and better agronomic traits were bred through six generations from the original transgenic plants. Results from insect bioassay and sequence analysis of the PCR products of plants from some homozygous lines indicated that the chimeric Bt29K gene was stably inherited in these transgenic cotton lines. The main agronomic characters of these homozygous cotton lines, such as boll productivity and fibre strength, were better than that of the original cotton cv. Jihe321.

Gitelman syndrome caused by a rare homozygous mutation in the SLC12A3 gene:A case report

BACKGROUND Gitelman syndrome(GS)is an unusual,autosomal recessive salt-losing tubulopathy characterized by hypokalemic metabolic alkalosis,hypomagnesemia and hypocalciuria.It is caused by mutations in the solute carrier family 12 member 3(SLC12A3)gene resulting in disordered function of the thiazidesensitive NaCl co-transporter.To date,many types of mutations in the SLC12A3 gene have been discovered that trigger different clinical manifestations.Therefore,gene sequencing should be considered before determining the course of treatment for GS patients.CASE SUMMARY A 55-year-old man was admitted to our department due to hand numbness and fatigue.Laboratory tests after admission showed hypokalemia,metabolic alkalosis and renal failure,all of which suggested a diagnosis of GS.Genome sequencing of DNA extracted from the patient’s peripheral blood showed a rare homozygous mutation in the SLC12A3 gene(NM_000339.2:chr16:56903671,Exon4,c.536T>A,p.Val179Asp).This study reports a rare homozygous mutation in SLC12A3 gene of a Chinese patient with GS.CONCLUSION Genetic studies may improve the diagnostic accuracy of Gitelman syndrome and improve genetic counseling for individuals and their families with these types of genetic disorders.

Rare large homozygous CFTR gene deletion in an Iranian patient with cystic fibrosis

Cystic fibrosis, a common autosomal recessive genetic disorder among Caucasians, is caused by defects in the transmembrane conductance regulatory(CFTR) gene. The analysis of CFTR gene mutations is useful to better characterize the disease, and for preconceptional screening, prenatal and preimplantation genetic diagnosis. Here we report the results of a genetic analysis in a 16-year-old boy from southwestern Iran diagnosed as having cystic fibrosis in infancy based on gastrointestinal and pulmonary manifestations, with positive sweat chloride tests. He lacked both normal and mutant forms of the fragment corresponding to the F508 allele in initial genetic studies. Multiplex ligationdependent probe amplification-based testing revealed a homozygous deletion spanning exons 4 to 10 of the CFTR gene. We predict an in-frame deletion removing 373 amino acids based on our sequencing results. Determining CFTR gene mutations in patients and their family members would be helpful to prevent the occurrence of new cases, especially in populations in which consanguinity is common.

Delivery Outcome in Women with Major Sickle Cell Syndrome: A Comparative Study of the Homozygous Forms “SS” versus the Heterozygous “SC”

Objectives: To determine the prevalence of women who delivered in the two major sickle cell syndromes, “SS” and “SC”, and to identify maternal and early neonatal prognosis inherent to each form. Material and Methods: This is a comparative, descriptive and retrospective cross-sectional study of 226 files of women carrying major sickle cell syndrome (66 cases of “SS” form versus 160 cases of “SC” form), collected from May 2008 to May 2013 at the Gynecology and Obstetrics Clinic of the Sylvanus Olympio’s University Hospital of Lomé. Data were processed by Epi Info 6 software. For comparison of variables, the Chi-2 test of Fisher with significance as p < 0.05 has been used, so is the calculation of Odds Ratio with its confidence interval at 95%. Results: Carriers of the two major sickle cell syndromes represent 0.8% of all the deliveries during the study period. Caesarean section, especially prophylactic one, was the dominant mode of delivery. The SS forms have been exposed to have more vaso-occlusive crises (22.7% vs. 13.1%;p = 0.04, OR = 0.31), more blood transfusion (57.6% vs. 29.4%;p = 7 × 10-5, OR = 3.2) and more puerperal infections (p < 0.05). Acute chest syndrome was not related to any of the two forms of sickle cell disease (13.6% vs. 8.1%;p = 0.15). The maternal mortality rate and the perinatal mortality among SS form against SC form were not significant (respectively 15.1% vs. 8.7%;20.9% vs. 17.1%). Conclusion: Maternal and fetal complications were present in both forms of major sickle cell syndrome but the "SS" form gave exposure to greater maternal morbidity. Resuscitative measures in adults and newborns should be reinforced at the delivery time of these “at-risk-pregnancies”.

Characterization of coronary atherosclerotic plaques in a homozygous familial hypercholesterolemia visualized by optical coherence tomography

Familial hypercholesterolemia(FH)is an autosomal dominant genetic disorder,which resulted in severe elevations in low-density lipoprotein cholesterol(LDL-C)and a markedly increased risk of early-onset coronary disease.[1]t is most frequently caused by loss-of-function mutations in genes affecting the LDL receptor,which clears LDL particles from plasma.

The Mesenteric-Caval Fistula: First Results of a New Technique in a Transperitoneal Reconstruction of the Caval Vein by Fulminant Thrombosis of the Inferior Vena Cava Based on Homozygous Antithrombin III-Deficiency

Recurrent thrombotic occlusions are one major problem in patients with thrombosis of the inferior vena cava. Due to this, we report a new surgical strategy for the construction of aorto-caval (mesenteric-caval) fistula in a patient with homozygous Antithrombin III (ATIII)-Deficiency. The patient survived postoperatively and only surgical complications grade I and II (Clavien-Dindo classification) were reported after short-term and one year follow-up. After one year, the CT-angiography did not show any caval thrombosis or stenosis and no restriction or occlusion of the fistula. Thus, the mesenteric-caval fistula could be safely performed and resulted in a satisfactory patency.

Detection of Homozygous Deletions and Mutations in the CDKN2A Gene in Hydatidiform Moles

OBJECTIVE To investigate homozygous deletions and mutations in the CDKN2A gene(p16 INK4a and p14 ARF gene)in hydatidiform moles. METHODS A total of 38 hydatidiform mole samples and 30 villi samples were examined for homozygous deletions in the CDKN2A gene by PCR and for mutations by DHPLC. RESULTS i)Among 38 hydatidiform mole samples, homozygous deletions in the p16 INK4a exon 1 were identified in 5 cases(13.2%),while no homozygous deletions were found in the p16I NK4aexon 1 of 30 early-pregnancy samples.The rates of those deletions in hydatidiform compared to early-pregnancy villi samples was statistically significant(P=0.036).ii)No homozygous deletions in the p14 ARF exon 1 or p16 INK4a exon 2 were found in any of the hydatidiform moles or early-preganancy samples.iii) In all hydatidiform moles and early-pregnancy villi samples,no mutations were detected by DHPLC. CONCLUSION We suggest there may be a close correlation between homozygous deletions in the CDKN2A gene and occurrence of hydatidiform moles variation in the CDKN2A gene is mainly caused by homozygous deletions,while mutations may be not a major cause.

门控心肌灌注显像预测纯合子家族性高胆固醇血症患者主要心脏不良事件的研究

目的:通过负荷+静息门控心肌灌注显像(gated myocardial perfusion imaging,G-MPI)评价纯合子家族性高胆固醇血症(homozygous familial hypercholesterolemia,HoFH)患者主要心脏不良事件(major adverse cardiovascular events,MACE)的预测价值。方法:对经临床和基因诊断确诊HoFH,在2010年6月至2022年3月,于我院行负荷+静息G-MPI检查的患者进行回顾性随访。图像分析采用17节段5分法,获得左心室心肌血流灌注及功能参数。随访患者MACE,采用Cox回归分析与MACE有关的预测因子。通过ROC分析预测因子的效能,采用Kaplan-Meier法和Log-rank检验比较不同组HoFH患者MACE发生率的差异。结果:共入选59例HoFH患者,中位随访时间6(4,9)年。随访期间20例(20/59,33.9%)患者出现MACE。G-MPI参数负荷灌注总积分(summed stress score,SSS)、静息灌注总积分(summed rest score,SRS)、总积分差值(summed difference score,SDS)、负荷左心室收缩末期容积(stress end-systolic volume,SESV)、负荷左心室射血分数(stress ejection fraction,SEF)、静息左心室收缩末期容积(rest end-systolic volume,RESV)、静息左心室射血分数(rest ejection fraction,REF)在MACE组与无MACE组,差异有统计学意义(P<0.05)。Cox回归分析显示SSS(HR=1.18,95%CI:1.088~1.279,P<0.001)是与HoFH患者出现MACE的独立预测因子。通过ROC分析确定预测HoFH患者出现MACE的SSS最佳截断值为5.5(AUC=0.813,95%CI:0.682~0.945,P<0.001),SSS≥5.5组MACE发生率明显高于SSS<5.5组(69.2%vs.15.0%,χ^(2)=27.085,P<0.001)。结论:负荷+静息G-MPI是对HoFH患者进行MACE评估的重要影像学手段,参数SSS是预测患者出现MACE的重要因素。

Asb14a 基因在斑马鱼肌间骨发育中的作用

为进一步研究肌间骨(intermuscular bone)发育的分子机制,利用CRISPR/Cas9打靶技术、茜素红染色及实时荧光定量PCR方法,研究了斑马鱼(Danio rerio)Asb14a基因敲除后肌间骨的发育情况。结果表明:本研究中成功构建了插入2 bp和缺失50 bp的Asb14a基因敲除纯合斑马鱼品系;茜素红染色显示,成年Asb14a^(-/-)突变体与野生斑马鱼相比,肌间骨数量显著减少了35%(P<0.0001),说明敲除Asb14a基因会减少斑马鱼肌间骨的数量;实时荧光定量PCR结果显示,骨骼发育相关基因(bmp6、sp7、sox6、alpl、collala、sox6和smad1)在Asb14a^(-/-)突变体中的表达水平发生了显著性变化,从分子角度验证了Asb14a基因与肌间骨发育间的关联性。研究表明,Asb14a基因参与了斑马鱼肌间骨发育,敲除该基因会影响斑马鱼肌间骨的生成,这一发现为进一步研究肌间骨发育的分子机制提供了重要线索。

亚甲基四氢叶酸还原酶纯合突变的颅内静脉窦血栓一例并文献复习

目的总结亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR)纯合突变致同型半胱氨酸(homocystine,Hcy)升高、诱发颅内静脉窦血栓形成(cerebral venous sinus thrombosis,CVST)的临床特点和诊疗过程。方法选取2023年1月3日解放军总医院第八医学中心的CVST患者1例,回顾性分析患者的临床、实验室资料,并复习既往相关文献。结果患者男,18岁,因“头痛伴恶心呕吐2 d”就诊,临床表现为头部持续胀痛,伴恶心呕吐,Hcy异常升高,影像学示上矢状窦、右侧横窦、乙状窦血栓形成,基因测序结果为MTHFR纯合突变。既往文献显示,MTHFR纯合突变与CVST无直接因果关系,但可导致Hcy水平升高,并间接增加CVST的风险。结论应重视CVST患者的Hcy检测,如发现Hcy无明显诱因的异常升高,应进一步完善CVST相关遗传因素的基因检测,尽早针对病因进行治疗。

Hif-1α在斑马鱼吞噬细胞迁移及发育中的生物学功能

探究斑马鱼低氧诱导因子-1α(Hif-1α)基因在中性粒细胞和巨噬细胞的发育和迁移中所起的作用。将斑马鱼分为野生对照组和Hif-1α基因突变组。使用CRISPR/Cas9技术对斑马鱼的Hif-1α基因进行突变。随后,通过苏丹黑B染色法观察了野生对照组和Hif-1α基因突变组中性粒细胞的染色情况,以及通过中性红染色法观察了巨噬细胞的染色情况并对结果进行了统计分析。结果显示成功构建缺失8个碱基的斑马鱼Hif-1α基因突变体,且Hif-1α基因突变的斑马鱼幼鱼发育3 d后,中性粒细胞迁移到急性损伤部位的数量显著减少,突变型斑马鱼后脑室中的小胶质巨噬细胞数量比野生型显著增多。综上,本研究成功构建了斑马鱼Hif-1α基因纯合突变体,同时表明Hif-1α基因具有抑制中性粒细胞向炎症区域迁移的作用,并促进脑室巨噬细胞的生长发育,为后续研究急性损伤模型提供基础。

Development of a single transcript CRISPR/Cas9 toolkit for efficient genome editing in autotetraploid alfalfa

Alfalfa(Medicago sativa.L.)is a globally significant autotetraploid legume forage crop.However,despite its importance,establishing efficient gene editing systems for cultivated alfalfa remains a formidable challenge.In this study,we pioneered the development of a highly effective ultrasonic-assisted leaf disc transformation system for Gongnong 1 alfalfa,a variety widely cultivated in Northeast China.Subsequently,we created a single transcript CRISPR/Cas9(CRISPR_2.0)toolkit,incorporating multiplex gRNAs,designed for gene editing in Gongnong 1.Both Cas9 and gRNA scaffolds were under the control of the Arabidopsis ubiquitin-10 promoter,a widely employed polymeraseⅡconstitutive promoter known for strong transgene expression in dicots.To assess the toolkit’s efficiency,we targeted PALM1,a gene associated with a recognizable multifoliate phenotype.Utilizing the CRISPR_2.0 toolkit,we directed PALM1 editing at two sites in the wild-type Gongnong 1.Results indicated a 35.1%occurrence of editing events all in target 2 alleles,while no mutations were detected at target 1 in the transgenic-positive lines.To explore more efficient sgRNAs,we developed a rapid,reliable screening system based on Agrobacterium rhizogenes-mediated hairy root transformation,incorporating the visible reporter MtLAP1.This screening system demonstrated that most purple visible hairy roots underwent gene editing.Notably,sgRNA3,with an 83.0%editing efficiency,was selected using the visible hairy root system.As anticipated,tetra-allelic homozygous palm1 mutations exhibited a clear multifoliate phenotype.These palm1 lines demonstrated an average crude protein yield increase of 21.5%compared to trifoliolate alfalfa.Our findings highlight the modified CRISPR_2.0 system as a highly efficient and robust gene editing tool for autotetraploid alfalfa.

DSG2基因p.Phe531Cys纯合突变所致致心律失常性右心室心肌病家系的临床表型和遗传学分析

目的对桥粒芯糖蛋白2(DSG2)基因p.Phe531Cys罕见纯合突变所致致心律失常性右心室心肌病(ARVC)一个家系的基因型-表型进行分析,并对突变位点进行生物信息学分析。方法临床观察性研究。收集2022年7月于南京医科大学附属江宁医院心血管内科住院的1例确诊为ARVC的先证者及其家系成员的临床资料进行评估。采集静脉血进行二代测序,并用Sanger测序验证。从美国国家生物技术信息中心(NCBI)数据库获取DSG2基因野生型氨基酸序列,通过人工编辑获得突变型氨基酸序列,对DSG2蛋白二级及三级结构进行预测分析。结果先证者(Ⅲ2)符合ARVC诊断标准,其余家系成员均不符合。先证者为DSG2基因p.Phe531Cys纯合突变,先证者女儿(Ⅳ1)携带DSG2基因杂合突变。生物信息学分析提示,该突变位点在脊椎动物中保守性较好,氨基酸突变后蛋白质稳定性降低。突变型DSG2及野生型DSG2蛋白质二级结构无明显差异,三级结构突变位点处的折叠角度发生变化。结论DSG2基因p.Phe531Cys纯合突变可导致ARVC,不同的基因型可导致不同的临床表现。