Complex heterozygous mutations in hereditary spherocytosis:A case report

BACKGROUND The aim of this study was to investigate the complex heterozygous mutations of ANK1 and SPTA1 in the same individual and improve our understanding of hereditary spherocytosis(HS)in children.We also hope to promote the application of gene detection technology in children with HS,with the goals of identifying more related gene mutations,supporting the acquisition of improved molecular genetic information to further reveal the pathogenesis of HS in children,and providing important guidance for the diagnosis,treatment,and prevention of HS in children.CASE SUMMARY A 1-year and 5-month-old patient presented jaundice during the neonatal period,mild anemia 8 months later,splenic enlargement at 1 year and 5 months,and brittle red blood cell permeability.Genetic testing was performed on the patient,their parents,and sister.Swiss Model software was used to predict the protein structure of complex heterozygous mutations in ANK1 and SPTA1.Genetic testing revealed that the patient harbored a new mutation in the ANK1 gene from the father and a mutation in the SPTA1 gene from the mother.Combined with the clinical symptoms of the children,it is suggested that the newly discovered complex heterozygous mutations of ANK1 and SPTA1 may be the cause,providing important guidance for revealing the pathogenesis,diagnosis,treatment,and promotion of gene detection technology in children with HS.CONCLUSION This case involves an unreported complex heterozygous mutation of ANK1 and SPTA1,which provides a reference for exploring HS.

Novel compound heterozygous GPR56 gene mutation in a twin with lissencephaly:A case report

BACKGROUND Lissencephaly(LIS)is a malformation of cortical development with broad gyri,shallow sulci and thickened cortex characterized by developmental delays and seizures.Currently,20 genes have been implicated in LIS.However,GRP56-related LIS has never been reported.GRP56 is considered one of the causative genes for bilateral frontoparietal polymicrogyria.Here,we report a twin infant with LIS and review the relevant literature.The twins both carried the novel compound heterozygous GPR56 mutations.CASE SUMMARY A 5-mo-old female infant was hospitalized due to repeated convulsions for 1 d.The patient had a flat head deformity that manifested as developmental delays and a sudden onset of generalized tonic-clonic seizures at 5 mo without any causes.The electroencephalography was normal.Brain magnetic resonance imaging revealed a simple brain structure with widened and thickened gyri and shallow sulci.The white matter of the brain was significantly reduced.Patchy long T1 and T2 signals could be seen around the ventricles,which were expanded,and the extracerebral space was widened.Genetic testing confirmed that the patient carried the GPR56 gene compound heterozygous mutations c.228delC(p.F76fs)and c.1820_1821delAT(p.H607fs).The unaffected father carried a heterozygous c.1820_1821delAT mutation,and the unaffected mother carried a heterozygous c.228delC mutation.The twin sister carried the same mutations as the proband.The patient was diagnosed with LIS.CONCLUSION This is the first case report of LIS that is likely caused by mutations of the GPR56 gene.

Child with adenylosuccinate lyase deficiency caused by a novel complex heterozygous mutation in the ADSL gene:A case report

BACKGROUND Adenylosuccinate lyase(ADSL)deficiency is a rare autosomal-recessive defect of purine metabolism caused by mutation of the ADSL gene.It can cause severe neurological impairment and diverse clinical manifestations,including epilepsy.CASE SUMMARY Here,we describe a 3-year-old Chinese boy who had both psychomotor retardation and refractory epilepsy.Magnetic resonance imaging showed myelin hypoplasia.Electroencephalography findings supported a diagnosis of epilepsy.Whole-exon sequencing revealed the presence of a novel complex heterozygous mutation in the ADSL gene:The splicing mutation c.154-3C>G and the missense mutation c.71C>T(p.Pro24Leu).Considering the patient’s clinical presentation and genetic test results,the complex heterozygous mutation was predicted to prevent both ADSL alleles from producing normal ADSL,which may have led to ADSL deficiency.Finally,the child was diagnosed with ADSL deficiency.CONCLUSION We identified a novel complex heterozygous mutation in the ADSL gene associated with ADSL deficiency,thus expanding the known spectrum of pathogenic mutations that cause ADSL deficiency.Additionally,we describe epilepsy that occurs in patients with ADSL deficiency.

Characteristics and Clinical Implication of UGT1A1 Heterozygous Mutation in Tumor

Background:The literature recommends that reduced dosage of CPT-11 should be applied in patients with UGT1 A1 homozygous mutations,but the impact of UGT1 A1 heterozygous mutations on the adverse reactions of CPT-11 is still not fully clear.Methods:A total of 107 patients with UGT1 A1 heterozygous mutation or wild-type,who were treated with CPT-11 from January 2018 to September 2021 in Peking University Third Hospital,were retrospectively enrolled.The adverse reaction spectra of patients with UGT1 A1*6 and UGT1 A1*28 mutations were analyzed.Adverse reactions were evaluated according to National Cancer Institute Common Terminology Criteria for Adverse Events(NCI-CTCAE) 5.0.The efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors(RECIST) 1.1.The genotypes of UGT1 A1*6 and UGT1 A1*28 were detected by digital fluorescence molecular hybridization.Results:There were 43 patients with UGT1 A1*6 heterozygous mutation,26 patients with UGT1 A1*28 heterozygous mutation,8 patients with UGT1 A1*6 and UGT1 A1*28 double heterozygous mutations,61 patients with heterozygous mutation at any gene locus of UGT1 A1*6 and UGT1 A1*28.Logistic regression analysis showed that the presence or absence of vomiting(P=0.013) and mucositis(P=0.005) was significantly correlated with heterozygous mutation of UGT1 A1*28,and the severity of vomiting(P<0.001) and neutropenia(P=0.021) were significantly correlated with heterozygous mutation of UGT1 A1*6.In colorectal cancer,UGT1 A1*6 was significantly correlated to diarrhea(P=0.005),and the other adverse reactions spectrum was similar to that of the whole patient cohort,and efficacy and prognosis were similar between patients with different genotypes and patients treated with reduced CPT-11 dosage or not.Conclusion:In clinical use,heterozygous mutations of UGT1 A1*6 and UGT1 A1*28 are related to the risk and severity of vomiting,diarrhea,neutropenia and mucositis in patients with Pan-tumor and colorectal cancer post CPT-11 therpy.In colorectal cancer,UGT1 A1*6 is significantly related to diarrhea post CPT-11 use,efficacy and prognosis is not affected by various genotypes or CPT-11 dosage reduction.

Digenic heterozygous mutations in EYS/LRP5 in a Chinese family with retinitis pigmentosa

Dear Editor,I am Dr.Ji-Hong Wu,from the Department of Ophthalmology,Eye＆ENT Hospital of Fudan University,China.I write to present a case report of retinitis pigmentosa（RP）caused by novel digenic heterozygous mutations in a Chinese family.

A novel mutation in FBN1 gene in autosomal dominant Marfan syndrome and macular degeneration in a Chinese consanguineous family

AIM: To report a novel mutation in FBN1 gene in a Chinese consanguineous family with common Marfan syndrome(MFS) phenotype and an unusual bilateral macular degeneration. METHODS: Ophthalmic, cardiovascular and systemic examinations were performed, and genomic DNA extracted from all living family members. The 24-32 exon mutations of FBN1 gene were screened by Sanger Sequencing in all family members and 100 unrelated healthy Chinese individuals. RESULTS: In the four-generation family, classic MFS phenotypes were observed in all 5 patients, 2 of them had peculiar phenotype of bilateral macular degeneration. Mutation screening in FBN1 identified a heterozygous missense mutation(c.3932 A>G, p.Y1311 C) with co-segregation. This mutation was found with the MFS phenotypes in all 5 patients but not in unaffected members or unrelated controls. CONCLUSION: A Chinese consanguineous MFS family with uncommon bilateral macular degeneration and an unreported c.3932 A>G mutation in FBN1 was identified. Our finding expands the FBN1 mutation spectrum and its possible role in the pathogenesis of Marfan syndrome.

Pseudoileus caused by primary visceral myopathy in a Han Chinese patient with a rare MYH11 mutation:A case report

BACKGROUND Chronic intestinal pseudo-obstruction(CIPO)is a syndrome of intestinal motor dysfunction caused by intestinal nerve,muscle,and/or Cajal stromal cell lesions.CIPO is a serious category of gastrointestinal dynamic dysfunction,which can eventually lead to the death of patients with intestinal failure.Due to considerable phenotypic heterogeneity,the estimated incidence of CIPO is 1/476190 and 1/416666 in men and women,respectively.According to the etiology,CIPO can be divided into idiopathic and secondary,of which the latter is the most common,often secondary to tumor,virus infection,connective tissue disease,neurological diseases,and endocrine diseases.Idiopathic CIPO in the intestinal tract is divided into visceral myopathy,neuropathy,and stromal cell lesions according to the location.Surgery is usually not recommended for CIPO,because it often does not benefit patients with CIPO,and postoperative intestinal obstruction is likely to occur,which may even worsen the condition.CASE SUMMARY Here,we describe the case of a 43-year-old male Han Chinese patient with a 15-year history of recurrent abdominal distention with no clear cause.The results of physical,biochemical,and other relevant examinations showed no clear abnormalities.Contrast-enhanced computed tomography(CT)indicated a large duodenum,clear expansion of the intestinal lumen,and CIPO.Whole exome sequencing(WES)of the patient and his mother confirmed the diagnosis of primary familial visceral myopathy type 2 chronic pseudoileus with a rare heterozygous gene mutation in MYH11.This is the second reported case of CIPO with a heterozygous MYH11[NM_001040113.1:c.5819delC(p.Pro1940Hisfs*91)]mutation.CONCLUSION This case report indicates that physicians can perform routine clinical examinations,CT,and WES to achieve a diagnosis and treatment of CIPO in early disease stages.

Crumbs homolog 2 mutation in two siblings with steroid-resistant nephrotic syndrome:Two case reports

BACKGROUND Crumbs homolog 2(CRB2)is a recently discovered gene that is closely related to the maintenance of normal polarity in podocytes;mutations can directly lead to steroid-resistant nephrotic syndrome(SRNS).However,the characteristics of nephrotic syndrome(NS)caused by CRB2 mutations have not been described.CASE SUMMARY We report a novel compound heterozygous mutation of the CRB2 gene in two siblings with SRNS.The two siblings had edema,proteinuria,hypoproteinemia and hyperlipidemia.Both their father and mother had normal phenotypes(no history of NS).Whole exon sequencing(WES)of the family showed a novel compound heterozygous mutation,c.2290(exon 8)C>T and c.3613(exon 12)G>A.Glucocorticoid therapy(methylprednisolone pulse therapy or oral prednisone)and immunosuppressive agents(tacrolimus)had no effect.During a 3-year follow-up after genetic diagnosis by WES,proteinuria persisted,but the patient was healthy.CONCLUSION CRB2 mutations related to SRNS often occur in exons 7,10,and 12.Clinical manifestations of SRNS caused by CRB2 mutations are often less severe than in other forms of SRNS.

Two novel mutations in the VPS33B gene in a Chinese patient with arthrogryposis,renal dysfunction and cholestasis syndrome 1:A case report

BACKGROUND The VPS33B(OMIM:608552)gene is located on chromosome 15q26.1.We found a female infant with autosomal recessive arthrogryposis,renal dysfunction and cholestasis syndrome 1(ARCS1)caused by mutation in VPS33B.The child was diagnosed with ARCS1(OMIM:208085)after the whole exome sequencing revealed two heterozygous mutations(c.96+1G>C,c.242delT)in the VPS33B gene.CASE SUMMARY We report a Chinese female infant with neonatal cholestasis disorder,who was eventually diagnosed with ARCS1 by genetic analysis.Genetic testing revealed two new mutations(c.96+1G>C and c.242delT)in VPS33B,which is the causal gene.The patient was compound heterozygous,and her parents were both heterozygous.CONCLUSION This study extends the mutational spectrum of the VPS33B gene to provide a molecular basis for the etiological diagnosis of ARCS1 and for genetic counseling of the family.

Autosomal recessive spinocerebellar ataxia type 4 with a VPS13D mutation:A case report

BACKGROUND Autosomal recessive spinocerebellar ataxia type 4(SCAR4)is a type of SCA that is a group of hereditary diseases characterized by gait ataxia.The main clinical features of SCAR4 are progressive cerebellar ataxia,pyramidal signs,neuropathy,and macrosaccadic intrusions.To date,many gene dysfunctions have been reported to be associated with SCAR4.CASE SUMMARY Here,we report a novel compound heterozygous mutation,c.3288delA(p.Asp1097-ThrfsTer6),in the VPS13D gene in a young female Chinese patient.The patient found something wrong with her legs about 10 years ago and presented with the typical characteristics of SCAR4 when she came to the hospital,including ataxia,neuropathy,and positive pyramidal signs.She was then diagnosed with SCAR4 and went home with symptomatic schemes.CONCLUSION SCAR4 is a hereditary disease characterized by ataxia,pyramidal signs,neuropathy,and macrosaccadic intrusions.We report a novel compound heterozygous mutation,c.3288delA(p.Asp1097ThrfsTer6),in the VPS13D gene,which enriches the gene mutation spectrum and provides additional information about SCAR4.

Compound heterozygous mutation in two unrelated cases of Chinese spinal muscular atrophy patients

Background Infantile proximal spinal muscular atrophy （SMA） is a common autosomal recessive neuromuscular disorder. Approximately 90-95% cases of SMA result from homozygous deletion of survival motor neuron gene 1（SMN1） and 5% cases are caused by compound heterozygous mutation （a SMN1 deletion on one allele and a subtle mutation on the other allele）.Methods In this research, two unrelated patients were clinically diagnosed according to the criteria of proximal SMA. Genetic diagnosis was performed to detect the homozygous deletion of exon 7 of SMN1 by PCR-restriction fragment length polymorphism （RFLP） and genomic sequencing. Multiplex ligation-dependent probe amplification （MLPA） analysis was carried out to measure copy numbers of SMN1, SMN2 and neuronal apoptosis inhibitor protein （NAIP） in the patients. Further sequencing of SMN1allele-specific PCR （AS-PCR） and SMN1 clones were also performed to analyze the point mutation of SMN1 gene. Additionally,the pedigree analysis of these two families was carried out to identify the transmission of the mutation.Results The inconsistent results using PCR-RFLP and genomic sequencing showed homozygous deletion of exon 7 of SMN1 and heterozygous deletion accompanied with a suspicious mutation in SMN1 gene, respectively. MLPA analysis of these two cases exhibited one SMN1 copy deletion. One identical c.863G〉T （p. Arg288Met） mutation was found in two cases by sequencing the SMN1 clones, which confirmed that both cases were SMA compound heterozygotes. One case showed partial conversion to form hybrid SMN （SMN2 17/SMN1 E8） identified by clones sequencing and another case carrying 3 SMN2 implied complete conversion from SMN1 to SMN2.Conclusion p. Arg288Met is more a disease-causing mutation than a polymorphism variation, and children with this mutation may have more severe phenotypes.

1例罕见α-地中海贫血产前诊断与家系分子遗传学分析

目的 对1例疑似携带罕见地中海贫血(简称地贫)的产前诊断胎儿进一步测序分析,对先证者进行家系分子遗传学分析。方法 运用血常规和血红蛋白电泳进行地贫筛查,采用gap-PCR法和PCR-RDB法检测24种地贫突变,对疑似罕见地贫进行基因测序分析。结果 先证者为--~(SEA)地贫与α2基因IVS-Ⅱ-119地贫双重杂合子,其IVS-Ⅱ-119地贫基因遗传自母方,--~(SEA)地贫基因遗传自父方。结论 --~(SEA)/α~(IVS-Ⅱ-119)α HbH地贫患儿的诊断,为罕见地贫的遗传咨询和产前诊断提供科学理论依据。

LRP5基因突变导致骨质疏松症-假性胶质瘤综合征一例报告

报告一例常染色体隐性遗传发病的骨质疏松症-假性胶质瘤综合征。先证者女性,23岁,父母非近亲结婚,出生后发现双目失明,婴儿期因发现右眼视网膜母细胞瘤行右眼球摘除术,9岁开始反复发生轻微外力骨折,诊断为成骨不全。查体发现脊柱侧凸畸形、胸廓畸形、双上肢肘外翻、四肢关节韧带松弛。双能X线吸收检测仪(dual energy X-ray absorptiometry,DXA)骨密度明显低于同龄人,腰椎1-4骨密度Z值-5,左髋骨密度Z值-1.8。X线摄片示全身骨小梁稀疏。Sanger测序显示低密度脂蛋白受体相关蛋白-5(lowdensity lipoprotein receptor-related protein 5,LRP5)基因的6号外显子和23号外显子发生复合杂合突变,导致p.Pro382Leu+p.Cys1611LeufsX33。本文通过文献复习对该病的临床表现和诊疗特点进行讨论及总结,以期帮助临床医生提高对这一疾病的认识。

KIF12基因新复合杂合突变导致进行性家族性肝内胆汁淤积1例报告

目的鉴定导致1例进行性家族性肝内胆汁淤积8(PFIC 8)患儿的KIF 12基因变异及其对功能的影响。方法分析1例PFIC 8患儿的临床资料,对患儿及其父母进行全外显子组测序,变异用一代测序进行验证。通过免疫荧光染色、细胞模型、实时定量聚合酶链式反应和蛋白质免疫印迹反应研究变异对基因功能的影响。同时对已报道的17例PFIC 8患儿的临床资料和基因变异进行文献复习。结果患儿,男,1个月14天,临床表现以发热和黄疸为主。全外显子组测序发现,患儿的KIF 12基因存在c.539G>A+c.928C>T复合杂合突变,此前未见报道。免疫荧光结果显示患儿肝细胞的KIF12蛋白的细胞内定位发生改变。在293T细胞中,c.539A、c.928T和c.539A+c.928T均可以使KIF12的mRNA表达减少,c.928T和c.539A+c.928T可使KIF12的蛋白水平表达降低(P<0.05)。文献回顾显示,已有7个KIF 12的纯合突变和1个复合杂合突变(c.538C>T+c.539G>A)被报道。在已报道的病例中,KIF 12的突变类型和PFIC 8患儿的肝外临床表型无关。结论在1例PFIC 8患儿中发现1种新的KIF 12复合杂合突变。在已发现的9个突变中,其类型与PFIC8肝外临床表型可能无关。

15例遗传性凝血因子V缺陷症先证者的临床特征与基因突变分析

目的分析15个遗传性凝血因子V(FV)缺陷症先证者的临床特征与基因突变类型,初步探讨其可能的分子致病机制。方法采用一期凝固法和ELISA法分别检测FV活性(FV:C)和FV抗原(FV:Ag)。用PCR扩增患者F5基因的25个外显子及其侧翼序列,并直接测序。利用蛋白质模型分析其可能的分子机制。结果在5例FV:C大于10%的先证者中,仅有1例出现轻微出血症状;在10例FV:C小于10%的先证者中,7例表现出各种出血症状。15例先证者共检出12个基因突变位点(其中8个为新的突变,1个为致病的多态性)。蛋白质模型分析表明,所有6种错义突变都会导致FV蛋白的构象改变,其中2种(p.Ser1781Arg和p.Asp96His)会减少氢键数量,从而导致局部蛋白质结构不稳定。结论这些遗传性FV缺陷症先证者的FV水平与各自的F5基因突变有关,其FV水平与出血症状具有较强的相关性。

First cases of MPV17 related mitochondrial DNA depletion syndrome with compound heterozygous mutations in p.R50Q/p.R50W:a case report

Mutations in MPV17 lead to severe mitochondrial DNA depletion syndrome(MTDPS).All known p.R50W variants in MPV17 are lethal.The homozygous variant p.R50Q in MPV17 among patients with Navajo neurohepatopathy is known to allow longer survival,although heterozygous variants p.R50Q have not been reported.This is the first clinical report in compound heterozygosity MPV17 mutation(p.R50W/p.R50Q).Three siblings were admitted due to multiple hepatic nodules;none presented neurological abnormalities.However,they suffered from severe hypoglycemia and cyclic vomiting.The diagnosis of MPV17-related MTDPS was confirmed by detection of a compound heterozygous MPV17 mutation(p.R50W/p.R50Q),and striking reduction of hepatic mitochondrial DNA.One patient developed pediatric-onset of hepatocellular carcinoma.Notably,all patients survived for extended periods,including two patients who received liver transplantation,which contrasted the high mortality rate associated with p.R50W mutations,as previously reported.The p.R50Q mutation might be associated with longer survival and improved liver transplantation outcomes.

肝豆状核变性患者的临床表型和ATP7B基因变异分析

目的:分析我国北方部分地区肝豆状核变性(wilson disease,WD)患者的临床特征及ATP7B基因变异情况。方法:以2018年11月至2022年4月期间在河南大学附属郑州颐和医院确诊的50例WD患者为研究对象,提取患者外周血基因组DNA,采用PCR扩增后用Sanger法对患者ATP7B基因外显子/内含子连接区进行序列分析。结果:50例WD患者根据临床症状分为肝型14例、脑型28例和其他型8例。50例WD患者中ATP7B基因变异结果:纯合子3例,复合杂合子32例和单一杂合突变13例,三处杂合突变1例,四处杂合子突变1例。共检测到30种不同的ATP7B基因突变,突变频率比较高的为p.Arg778Leu,p.Pro992Leu,p.Ala874Val,p.Arg919Trp,p.Val1106Ile。结论:本研究发现肝型WD患者发病早期主要表现为转氨酶升高,血清铜蓝蛋白降低,且以幼儿为主。p.Arg778Leu和p.Pro992Leu为ATP7B基因常见的突变,共发现30种ATP7B基因突变,为WD的早期确诊、家系筛查及产前诊断提供科学依据。

ALOXE3基因突变致轻型常染色体隐性先天性鱼鳞病一例

目的:检测1例常染色体隐性先天性鱼鳞病家系的基因突变情况。方法:提取患者及其父母、100名健康对照外周血DNA,对患者DNA行高通量测序,确定突变位点,再用Sanger测序法对患者和其父母的DNA进行双向验证。结果:在患者DNA中检测到ALOXE3基因c.1208A>G(p.His403Arg)及c.1131del(p.Ile378Sfs*70)复合杂合突变;母亲检出c.1208A>G(p.His403Arg)杂合变异,父亲检出c.1131del(p.Ile378Sfs*70)杂合变异。在检出的2个突变中,移码突变c.1131del为首次报道的突变。100名健康对照者均未见相同突变。结论:本例患者检测到ALOXE3基因c.1208A>G及c.1131del复合杂合突变,推测错义突变c.1208A>G的存在可能是患者临床表现较轻的原因。新报道的突变(c.1131del)丰富了该病基因突变谱。

早发型球形细胞脑白质营养不良1例

对GALC基因复合杂合变异引起早发型球形细胞脑白质营养不良(Krabbe病)1例患儿进行回顾性分析。患儿,女,4月龄,因“无明显诱因出现拒奶,精神差,嗜睡,抽搐,发热”入院。头颅MRI显示双侧小脑半球、双侧内囊后肢及双侧侧脑室旁对称性异常信号,胼胝体菲薄,髓鞘化形成进程落后于同龄儿水平。高通量测序结果显示患儿GALC基因存在复合杂合突变(NM_000153.4):c.[908+1G>A];[194G>A],分别来源于患儿父亲和母亲,c.908+1G>A已见报道,c.194G>A为首次报告。应用高通量测序技术可高效、精准的确诊Krabbe病,协助临床对该病进行鉴别及诊断。

酪氨酸羟化酶基因新型突变所致多巴反应性肌张力障碍1例

多巴反应性肌张力障碍临床罕见,发病率低。本文报告1例酪氨酸羟化酶(tyrosine hydroxylase,TH)基因新型突变致多巴反应性肌张力障碍患者的临床资料,为临床诊治提供参考。患者为29岁女性,肢体震颤伴手足姿势异常19年,儿童期急性起病,慢性加重,主要表现为四肢震颤,行走时足尖着地及双手肌肉痉挛,症状存在昼夜波动性特点。查体可见双上肢轻微姿势性及静止性震颤。基因检测提示患者TH基因EXON9 C.943G>A错义突变(遗传自父亲)及TH基因EXON8 C.851A>G错义突变(遗传自母亲)的杂合突变,C.851A>G位点既往未见报告。予小剂量左旋多巴治疗,患者症状明显改善。分析该病例特点及文献回顾表明,多巴反应性肌张力障碍患者诊断主要依赖于基因检测,且不同的临床表型对左旋多巴反应不同。