Mental retardation,seizures and language delay caused by new SETD1B mutations:Three case reports

BACKGROUND The SETD1B gene is instrumental in human intelligence and nerve development.Mutations in the SETD1B gene have been linked in recent studies to neurodevelopmental disorders,seizures,and language delay.CASE SUMMARY This study aimed to analyze the clinical manifestations and treatment of three patients suffering from mental retardation,epilepsy,and language delay resulting from a new mutation in the SETD1B gene.Three individuals with these symptoms were selected,and their clinical symptoms,gene test results,and treatment were analyzed.This article discusses the impact of the SETD1B gene mutation on patients and outlines the treatment approach.Among the three patients(two females and one male,aged 8,4,and 1,respectively),all exhibited psychomotor retardation,attention deficit,and hyperactivity disorder,and two had epilepsy.Antiepileptic treatment with sodium tripolyvalproate halted the seizures in the affected child,although mental development remained somewhat delayed.Whole exome sequencing revealed new mutations in the SETD1B gene for all patients,specifically with c.5473C>T(p.Arg1825trp),c.4120C>T(p.Gln1374*,593),c.14_15insC(p.His5Hisfs*33).CONCLUSION Possessing the SETD1B gene mutation may cause mental retardation accompanied by seizures and language delay.Although the exact mechanism is not fully understood,interventions such as drug therapy,rehabilitation training,and family support can assist patients in managing their symptoms and enhancing their quality of life.Furthermore,genetic testing supplies healthcare providers with more precise diagnostic and therapeutic guidance,informs families about genetic disease risks,and contributes to understanding disease pathogenesis and drug research and development.

Mutational landscape of TP53 and CDH1 in gastric cancer

In this editorial we comment on an article published in a recent issue of the World J Gastrointest Surg.A common gene mutation in gastric cancer(GC)is the TP53 mutation.As a tumor suppressor gene,TP53 is implicated in more than half of all tumor occurrences.TP53 gene mutations in GC tissue may be related with clinical pathological aspects.The TP53 mutation arose late in the progression of GC and aided in the final switch to malignancy.CDH1 encodes E-cadherin,which is involved in cell-to-cell adhesion,epithelial structure maintenance,cell polarity,differentiation,and intracellular signaling pathway modulation.CDH1 mutations and functional loss can result in diffuse GC,and CDH1 mutations can serve as independent prognostic indicators for poor prognosis.GC patients can benefit from genetic counseling and testing for CDH1 mutations.Demethylation therapy may assist to postpone the onset and progression of GC.The investigation of TP53 and CDH1 gene mutations in GC allows for the investigation of the relationship between these two gene mutations,as well as providing some basis for evaluating the prognosis of GC patients.

Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures

Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.

CHCHD2 Thr61Ile mutation impairs F1F0-ATPase assembly in in vitro and in vivo models of Parkinson's disease

Mitochondrial dysfunction is a significant pathological alte ration that occurs in Parkinson's disease(PD),and the Thr61lle(T61I)mutation in coiled-coil helix coiled-coil helix domain containing 2(CHCHD2),a crucial mitochondrial protein,has been reported to cause Parkinson's disease.FIFO-ATPase participates in the synthesis of cellular adenosine triphosphate(ATP)and plays a central role in mitochondrial energy metabolism.However,the specific roles of wild-type(WT)CHCHD2 and T611-mutant CHCHD2 in regulating F1FO-ATPase activity in Parkinson's disease,as well as whether CHCHD2 or CHCHD2 T61I affects mitochondrial function through regulating F1FO-ATPase activity,remain unclea r.Therefore,in this study,we expressed WT CHCHD2 and T61l-mutant CHCHD2 in an MPP^(+)-induced SH-SY5Y cell model of PD.We found that CHCHD2 protected mitochondria from developing MPP^(+)-induced dysfunction.Under normal conditions,ove rexpression of WT CHCHD2 promoted F1FO-ATPase assembly,while T61I-mutant CHCHD2 appeared to have lost the ability to regulate F1FO-ATPase assembly.In addition,mass spectrometry and immunoprecipitation showed that there was an interaction between CHCHD2 and F1FO-ATPase.Three weeks after transfection with AAV-CHCHD2 T61I,we intraperitoneally injected 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into mice to establish an animal model of chronic Parkinson's disease and found that exogenous expression of the mutant protein worsened the behavioral deficits and dopaminergic neurodegeneration seen in this model.These findings suggest that WT CHCHD2 can alleviate mitochondrial dysfunction in PD by maintaining F1F0-ATPase structure and function.

Assessment of pathogenicity and functional characterization of APPL1 gene mutations in diabetic patients

BACKGROUND Adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 1(APPL1)plays a crucial role in regulating insulin signaling and glucose metabolism.Mutations in the APPL1 gene have been associated with the development of maturity-onset diabetes of the young type 14(MODY14).Currently,only two mutations[c.1655T>A(p.Leu552*)and c.281G>A p.(Asp94Asn)]have been identified in association with this disease.Given the limited understanding of MODY14,it is imperative to identify additional cases and carry out comprehensive research on MODY14 and APPL1 mutations.AIM To assess the pathogenicity of APPL1 gene mutations in diabetic patients and to characterize the functional role of the APPL1 domain.METHODS Patients exhibiting clinical signs and a medical history suggestive of MODY were screened for the study.Whole exome sequencing was performed on the patients as well as their family members.The pathogenicity of the identified APPL1 variants was predicted on the basis of bioinformatics analysis.In addition,the pathogenicity of the novel APPL1 variant was preliminarily evaluated through in vitro functional experiments.Finally,the impact of these variants on APPL1 protein expression and the insulin pathway were assessed,and the potential mechanism underlying the interaction between the APPL1 protein and the insulin receptor was further explored.RESULTS A total of five novel mutations were identified,including four missense mutations(Asp632Tyr,Arg633His,Arg532Gln,and Ile642Met)and one intronic mutation(1153-16A>T).Pathogenicity prediction analysis revealed that the Arg532Gln was pathogenic across all predictions.The Asp632Tyr and Arg633His variants also had pathogenicity based on MutationTaster.In addition,multiple alignment of amino acid sequences showed that the Arg532Gln,Asp632Tyr,and Arg633His variants were conserved across different species.Moreover,in in vitro functional experiments,both the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were found to downregulate the expression of APPL1 on both protein and mRNA levels,indicating their pathogenic nature.Therefore,based on the patient’s clinical and family history,combined with the results from bioinformatics analysis and functional experiment,the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were classified as pathogenic mutations.Importantly,all these mutations were located within the phosphotyrosinebinding domain of APPL1,which plays a critical role in the insulin sensitization effect.CONCLUSION This study provided new insights into the pathogenicity of APPL1 gene mutations in diabetes and revealed a potential target for the diagnosis and treatment of the disease.

转录因子HNF1α基因c.493T>C位点突变对其蛋白质水平的影响

肝细胞核因子1α(hepatocyte nuclear factor 1α,HNF1α)作为一种转录因子在维持胰腺β细胞功能、肝脏脂质代谢等过程中发挥着重要的调控作用。该基因突变是导致青少年起病的成人型糖尿病(maturity onset diabetes of the young,MODY)3型的致病原因,目前已报道的该基因的突变位点众多,如P291fsinsC、P112L等常见的突变位点,但其具体的分子机制尚不清楚。本研究对前期工作中发现的1例携带有HNF1α基因c.493T>C位点突变的MODY3患者,通过应用Mutation Surveyor软件分析突变位点的致病性,构建HNF1α野生型和突变型真核表达质粒,采用Western blot检测两种质粒表达的HNF1α蛋白质的量和稳定性变化,结果发现Mutation Surveyor软件分析提示c.493T>C位点突变可能为致病性变异基因,Western blot显示突变型真核质粒表达的HNF1α蛋白质的量和稳定性均明显降低,差异均具有统计学意义(P<0.05)。上述结果表明c.493T>C(p.Trp165Arg)变异显著影响HNF1α的表达量及稳定性,可能为其导致疾病发生的原因,为后续深入探究MODY3的分子致病机制提供了新的方向。

转录因子HNF1A、HNF4A和FOXA2调节肝细胞蛋白质N-糖基化

Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells.

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.

HNF1β在输卵管妊娠黏膜中的表达及意义

目的 检测输卵管妊娠中输卵管上皮HNF1β的蛋白表达情况,初步探讨HNF1β在输卵管妊娠发生机制中的作用。方法选取34例输卵管妊娠组织,以20例育龄期女性正常输卵管组织及14例正常增殖期子宫内膜作为对照,应用免疫组织化学方法分别检测各组标本中HNF1β的表达情况。结果 正常输卵管上皮不表达HNF1β蛋白,而在输卵管妊娠中出现异常表达(P<0.01);输卵管妊娠时,输卵管上皮HNF1β表现出与正常子宫内膜相似的表达模式。结论 HNF1β的异常表达可能是输卵管妊娠的重要分子事件。输卵管妊娠中输卵管上皮可能模拟正常子宫内膜的调控机制。

Mutational separation and clinical outcomes of TP53 and CDH1 in gastric cancer

BACKGROUND Gastric cancer(GC)is a deadly tumor with the fifth highest occurrence and highest global mortality rates.Owing to its heterogeneity,the underlying mechanism of GC remains unclear,and chemotherapy offers little benefit to individuals.AIM To investigate the clinical outcomes of TP53 and CDH1 mutations in GC.METHODS In this study,202 gastric adenocarcinoma tumor tissues and their corresponding normal tissues were collected.A total of 490 genes were identified using target capture.Through t-test and Wilcoxon rank-sum test,somatic mutations,microsatellite instability,and clinical statistics,including overall survival,were detected,compared,and calculated.RESULTS The mutation rates of 32 genes,including TP53,SPEN,FAT1,and CDH1 exceeded 10%.TP53 mutations had a slightly lower overall occurrence rate(33%).The TP53 mutation rate was significantly higher in advanced stages(stage Ⅲ/Ⅳ)than that in early stages(stage Ⅰ/Ⅱ)(P<0.05).In contrast,CDH1 mutations were significantly associated with diffuse GC.TP53 is related to poor prognosis of advanced-stage tumors;nevertheless,CDH1 corresponds to a diffuse type of cancer.TP53 is exclusively mutated in CDH1 and is primarily affected by two distinct GC mechanisms.CONCLUSION Different somatic mutation patterns in TP53 and CDH1 indicate two major mechanisms of GC.

Co-existing squamous cell carcinoma and chronic myelomonocytic leukemia with ASXL1 and EZH2 gene mutations:A case report

BACKGROUND Chronic myelomonocytic leukemia(CMML),a rare clonal hematopoietic stem cell disorder characterized by myelodysplastic syndrome and myeloproliferative neoplasms,has a generally poor prognosis,and easily progresses to acute myeloid leukemia.The simultaneous incidence of hematologic malignancies and solid tumors is extremely low,and CMML coinciding with lung malignancies is even rarer.Here,we report a case of CMML,with ASXL1 and EZH2 gene mutations,combined with non-small cell lung cancer(lung squamous cell carcinoma).CASE SUMMARY A 63-year-old male,suffering from toothache accompanied by coughing,sputum,and bloody sputum for three months,was given a blood test after experiencing continuous bleeding resulting from a tooth extraction at a local hospital.Based on morphological results,the patient was diagnosed with CMML and bronchoscopy was performed in situ to confirm the diagnosis of squamous cell carcinoma in the lower lobe of the lung.After receiving azacitidine,programmed cell death protein 1,and platinum-based chemotherapy drugs,the patient developed severe myelosuppression and eventually fatal leukocyte stasis and dyspnea.CONCLUSION During the treatment and observation of CMML and be vigilant of the growth of multiple primary malignant tumors.

Major depressive disorder is correlated with the mitochondrial ND1 T3394C mutation in two Han Chinese families:Two case reports

BACKGROUND Major depressive disorder(MDD)is the most frequent reason of disabled people in the world,as reported by the World Health Organization.However,the diagnosis of MDD is mainly based on clinical symptoms.CASE SUMMARY The clinical,genetic,and molecular characteristics of two Chinese families with MDD are described in this study.There were variable ages of onset and severity in depression among the families.Both Chinese families had a very low prevalence of MDD.The mitochondrial genomes of these pedigrees were sequenced and indicated a homoplasmic T3394C(Y30H)mutation,with the polymorphism located at a highly conserved tyrosine at position 30 of ND1.The analysis also revealed unique sets of mitochondrial DNA(mtDNA)polymorphisms originating from haplogroups M9a3 and M9a.CONCLUSION This finding of the T3394C mutation in two unrelated depressed patients provides strong evidence that this mutation may have a part in the etiology of MDD.However,In these two Chinese families having the T3394C mutation,no functional mt DNA mutation was observed.Therefore,T3394C mutations are related with MDD,and the phenotypic manifestation of these mutations may be affected by changes in nuclear genes or environmental factors.

CDKN1C gene mutation causing familial Silver–Russell syndrome:A case report and review of literature

BACKGROUND Cyclin-dependent kinase inhibitor 1C(CDKN1C)is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest.CDKN1C mutations can lead to IMAGe syndrome(CDKN1C allele gain-of-function mutations lead to intrauterine growth restriction,metaphyseal dysplasia,adrenal hypoplasia congenital,and genitourinary malformations).We present a Silver-Russell syndrome(SRS)pedigree that was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).The affected family members had an SRS phenotype but did not have limb asymmetry or adrenal insufficiency.The amino acid changes in this specific region were located in a narrow functional region that contained mutations previously associated with IMAGe syndrome.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.CASE SUMMARY We describe the case of an 8-year-old girl who initially presented with short stature.Her height was 91.6 cm,and her weight was 10.2 kg.Physical examination revealed that she had a relatively large head,an inverted triangular face,a protruding forehead,a low ear position,sunken eye sockets,and irregular cracked teeth but no limb asymmetry.Family history:The girl’s mother,greatgrandmother,and grandmother’s brother also had a prominent forehead,triangular face,and severely proportional dwarfism but no limb asymmetry or adrenal insufficiency.Exome sequencing of the girl revealed a new heterozygous CDKN1C(NM_000076.2)c.836G>A mutation,resulting in a variant with a predicted evolutionarily highly conserved arginine substituted by histidine(p.Arg279His).The same causative mutation was found in both the proband’s mother,great-grandmother,and grandmother’s brother,who had similar phenotypes.Thus far,we found an SRS pedigree,which was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).Although the SRS-related CDKN1C mutation is in the IMAGe-related mutation hotspot region[the proliferating cell nuclear antigen(PCNA)domain],no adrenal insufficiency was reported in this SRS pedigree.The reason may be that the location of the genomic mutation and the type of missense mutation determines the phenotype.The proband was treated with recombinant human growth hormone(rhGH).After 1 year of rhGH treatment,the height standard deviation score of the proband increased by 0.93 standard deviation score,and her growth rate was 8.1 cm/year.No adverse reactions,such as abnormal blood glucose,were found.CONCLUSION Functional mutations in CDKN1C can lead to familial SRS without limb asymmetry,and some patients may have glucose abnormalities.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.

Novel HNF1A gene mutation in maturity-onset diabetes of the young:A case report

BACKGROUND Maturity-onset diabetes of the young 3(MODY3),caused by mutations in the HNF1A gene,is the most common subtype of MODY.The diagnosis of MODY3 is critical because a low dose of sulfonylurea agents can achieve glucose control.CASE SUMMARY We describe a patient with MODY3 involving a novel splicing mutation,in whom low-dose gliclazide was sufficient to control clinically significant hyperglycemia.Sanger sequencing identified a splicing HNF1A mutation in 12q24 NM_000545.5 Intron5 c.1108-1G>A.Glycemic control has been maintained without insulin therapy for 28 mo after the diagnosis of diabetes.CONCLUSION This case report highlights a novel HNF1A gene mutation in MODY3 that is responsive to sulfonylurea therapy.

HNF1A mutation in a Thai patient with maturity-onset diabetes of the young: A case report

BACKGROUND Maturity-onset diabetes of the young(MODY)is the most common form of monogenic diabetes.The disease is transmitted in autosomal dominant mode and diabetes is usually diagnosed before age 25 year.MODY 3 is caused by mutation of hepatocyte nuclear factor(HNF)1A genes and is the most common MODY subtype.Diagnosis of MODY 3 is crucial since glycemic control can be accomplished by very low dose of sulfonylurea.In this report we described a Thai MODY 3 patient who had excellence plasma glucose control by treating with glicazide 20 mg per day and insulin therapy can be discontinued.CASE SUMMARY A 31-year-old woman was diagnosed diabetes mellitus at 14 years old.The disease was transmitted from her grandmother and mother compatible with autosomal dominant inheritance.Sanger sequencing of proband’s DNA identified mutation of HNF1A at codon 203 which changed amino acid from arginine to cysteine(R203C).This mutation was carried only by family members who have diabetes.The patient has been treated effectively with a combination of oral hypoglycemic agents and must include a very low dose of glicazide(20 mg/d).Insulin therapy was successfully discontinued.CONCLUSION We demonstrated a first case of pharmacogenetics in Thai MODY 3 patient.Our findings underscore the essential role of molecular genetics in diagnosis and guidance of appropriate treatment of diabetes mellitus in particular patient.

乳腺癌组织中HNF1α⁃AS1和HNF4α⁃AS1水平及临床意义

目的探讨乳腺癌组织的HNF1α反义RNA 1(HNF1α-AS1)和HNF4α反义RNA 1(HNF4α-AS1)水平及临床意义。方法采用实时定量PCR检测2020年1月至2021年12月手术切除的106对乳腺癌组织和癌旁组织的HNF1α-AS1、HNF4α-AS1水平,分析组织两者水平与乳腺癌临床病理特征的关系,Kaplan-Meier Plotter数据库在线分析乳腺癌RNAseq数据中2976例患者的HNF1α-AS1、HNF4α-AS1水平与预后的关系。结果HNF1α-AS1水平为5.245±0.202,高于癌旁组织的1.436±0.044,而HNF4α-AS1水平为0.836±0.035,低于癌旁组织的1.337±0.048,差异有统计学意义(P<0.05),进一步分析显示乳腺癌组织的HNF1α-AS1和HNF4α-AS1水平呈负相关(r=-0.453,P<0.001)。组织HNF1α-AS1水平与TNM分期、组织学分级和Nottingham预后指数(NPI)有关(P<0.05),而组织HNF4α-AS1水平与肿瘤大小、淋巴结转移、TNM分期、组织学分级、HER-2表达和NPI有关(P<0.05)。Kaplan-Meier Plotter在线分析显示,HNF1α-AS1水平与乳腺癌的总生存期(OS)无关(HR=1.28,95%CI:0.99~1.64,P=0.056),而HNF4α-AS1水平与乳腺癌的OS有关,其中高水平者的中位OS优于低水平组(HR=0.75,95%CI:0.59~0.96,P=0.020)。结论HNF1α-AS1在乳腺癌中高表达而HNF4α-AS1为低表达,两者异常表达在乳腺癌恶性进展发挥作用,有望成为乳腺癌防治的靶点。

A novel NF1 frame-shift mutation c.703＿704delTA in a Chinese pedigree with neurofibromatosis type 1

We analyzed the clinical features and NF1 gene mutation in a Chinese pedigree of neurofibromatosis type 1（NF1）. Three members of this family were NF1 patients presenting with different clinical phenotypes and the others were asymptomatic. Exons of NF1 were amplified by polymerase chain reaction, sequenced, compared with a reference database. One novel NF1 frame-shift mutation c.703_704delTA, which resulted in a premature stop signal at codon 720 and the synthesis of truncated, was revealed. This mutation segregated with the NF1 members is likely responsible for the pathogenesis of NF1 in the family.

Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature

Steroid 5β-reductase [aldo-keto reductase family 1 member D1(AKR1D1)] is essential for bile acid biosynthesis. Bile acid deficiency caused by genetic defects in AKR1D1 leads to life-threatening neonatal hepatitis and cholestasis. There is still limited experience regarding the treatment of this disease. We describe an infant who presented with hyperbilirubinemia and coagulopathy but normal bile acid and γ-glutamyltransferase. Gene analysis was performed using genomic DNA from peripheral lymphocytes from the patient, his parents, and his elder brother. The patient was compound heterozygous for c.919C>T in exon 8 and exhibited a loss of heterozygosity of the AKR1D1 gene, which led to an amino acid substitution of arginine by cysteine at amino acid position 307(p.R307C). Based on these mutations, the patient was confirmed to have primary 5β-reductase deficiency. Ursodeoxycholic acid(UDCA) treatment did not have any effect on the patient. However, when we changed to chenodeoxycholic acid(CDCA) treatment, his symptoms and laboratory tests gradually improved. It is therefore crucial to supplement with an adequate dose of CDCA early to improve clinical symptoms and to normalize laboratory tests.

The R1947X mutation of NF1 causing autosomal dominant neurofibromatosis type 1 in a Chinese family

Neurofibromatosis type 1 is a common autosomal dominant disorder with a high rate of penetrance. It is caused by the mutation of the tumor suppressor gene NF1, which encodes neurofibromin. The main function of neurofibromin is down-regulating the biological activity of the proto-oncoprotein Ras by acting as a Ras-specific GTPase activating protein. In this study, we identified a Chinese family affected with neurofibromatosis type 1. The known gene NF1 associated with NF1 was studied by linkage analysis and by direct sequencing of the entire coding region and exon-intron boundaries of the NF1 gene. The R1947X mutation of NF1 was identified, which was co-segregated with affected individuals in the Chinese family, but not present in unaffected family members. This is the first report, which states that the R1947X mutation of NF1 may be one of reasons for neurofibromatosis type 1 in Chinese population.

Distinctive Drug-resistant Mutation Profiles and Interpretations of HIV-1 Proviral DNA Revealed by Deep Sequencing in Reverse Transcriptase

Objective To investigate distinctive features in drug-resistant mutations （DRMs） and interpretations for reverse transcriptase inhibitors （RTIs） between proviral DNA and paired viral RNA in HIV-l-infected patients. Methods Forty-three HIV-l-infected individuals receiving first-line antiretroviral therapy were recruited to participate in a multicenter AIDS Cohort Study in Anhui and Henan Provinces in China in 2004. Drug resistance genotyping was performed by bulk sequencing and deep sequencing on the plasma and whole blood of 77 samples, respectively. Drug-resistance interpretation was compared between viral RNA and paired proviral DNA. Results Compared with bulk sequencing, deep sequencing could detect more DRMs and samples with DRMs in both viral RNA and proviral DNA. The mutations M1841 and M2301 were more prevalent in proviral DNA than in viral RNA （Fisher＇s exact test, P〈0.05）. Considering ＇majority resistant variants＇, 15 samples （19.48%） showed differences in drug resistance interpretation between viral RNA and proviral DNA, and 5 of these samples with different DRMs between proviral DNA and paired viral RNA showed a higher level of drug resistance to the first-line drugs. Considering ＇minority resistant variants＇, 22 samples （28.57%） were associated with a higher level of drug resistance to the tested RTIs for proviral DNA when compared with paired viral RNA. Conclusion Compared with viral RNA, the distinctive information of DRMs and drug resistance interpretations for proviral DNA could be obtained by deep sequencing, which could provide more detailed and precise information for drug resistance monitoring and the rational design of optimal antiretroviral therapy regimens.