Advances in the study of POAG-related genes and central nervous system diseases / 国际眼科杂志(Guoji Yanke Zazhi)

@#In recent years, considerable progress has been made in the study of glaucoma, especially primary open angle glaucoma(POAG). A series of POAG genes has been identified through genetic linkage analysis and genome-wide association studies(GWAS), which significantly advanced the study of glaucoma genetics. The latest perspective suggests that glaucoma is a disease of the central nervous system(CNS). A large number of basic clinical studies have demonstrated the close association between CNS disease and glaucoma. Among these studies, discoveries related to genetics are of prominence.

Preimplantation genetic diagnosis for infertile males with autosomal dominant polycystic kidney disease / 中华男科学杂志

<p><b>Objective</b>Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic renal diseases, which may cause oligoasthenospermia and azoospermia and result in male infertility. This study aimed to analyze the outcomes of preimplantation genetic diagnosis (PGD) in male patients with ADPKD-induced infertility.</p><p><b>METHODS</b>We retrospectively analyzed the clinical data on 7 male patients with ADPKD-induced infertility undergoing PGD from April 2015 to February 2017, including 6 cases of oligoasthenospermia and 1 case of obstructive azoospermia, all with the PKD1 gene heterozygous mutations. Following intracytoplasmic sperm injection (ICSI), we performed blastomere biopsy after 5 or 6 days of embryo culture and subjected the blastomeres to Sureplex whole-genome amplification, followed by haplotype linkage analysis, Sanger sequencing, array-based comparative genomic hybridization to assess the chromosomal ploidy of the unaffected embryos, and identification of the unaffected euploid embryos for transfer.</p><p><b>RESULTS</b>One PGD cycle was completed for each of the 7 patients. Totally, 26 blastocysts were developed, of which 12 were unaffected and diploid. Clinical pregnancies were achieved in 6 cases following 7 cycles of frozen embryo transplantation, which included 5 live births and 1 spontaneous abortion.</p><p><b>CONCLUSIONS</b>For males with ADPKD-induced infertility, PGD may contribute to high rates of clinical pregnancy and live birth and prevent ADPKD in the offspring as well. This finding is also meaningful for the ADPKD patients with normal fertility.</p>

Mutation analysis of a Chinese pedigree of Leber hereditary optic neuropathy with only male patients / 中华实验眼科杂志

Background Leber hereditary optic neuropathy (LHON) is a maternally inherited disorder characterized by a bilateral acute or subacute painless central visual loss in young adults,predominately in males.So far no one theory can completely explain all clinical manifestations of LHON.Objective This study was to investigate whether there is a linkage between X-chromosomal and mitochondrial mutation in the inheritance of a Chinese LHON pedigree with only male patients.Methods This study was approved by Ethic Committee of Affiliated First Hospital of Zhengzhou University and followed by Declaration of Helsinki.A Chinese LHON pedigree was included in Anyang city from January 2008 to August 2016.Periphery blood of 5-10 ml was collected from 4 sufferers,13 maternal members and 10 non-maternal members for DNA extraction and PCR sequencing.The gene scanning and genotyping analysis were performed by ABI-PRISM 3100 genetic analyzer and Genotyper 3.7 software,and linkage analysis was carried out with Linkage software for the calculation of logarithm of odds (LOD).Mitochondrial DNA (mtDNA) sequence,fluorescence-based Genescan for X-chromosomal sequence were analyzed in the propositus and haplotype was evaluated.Results A total of 5 generations and 71 families were included in the pedigree,with 6 male sufferers,30 maternal members and 41 non-maternal members.The visual acuity was ≤0.10,and the central visual field defection,the optic nerve flushing was found in the acute phase,different levels of the optic nerve fibers atrophy were found in the chronic phase;visual evoked potential (VEP) amplitude was low and peak latency were found in the male patients,and no any ocular abnormality was seen in the maternal members,meeting a maternally inherited characteristics,with the penetranee of 20％.The three primnary mutations were not been found in this family bv PCR sequencing,mtDNA sequencing appeared 31 variation of loci in the proband,including a known G3635A mutation,as well as an unknown ND5 A12340G missense mutation and ND4 T11809C synonymous mutation as well as 28 polymorphism of locus,and the proband was mitochondrial haplotype F1.The maternal families were mutation carriers of G3635A and AI2340G loci,while the same mutation was not found in the normal family members and 107 controls.The maximum two point parametric LOD score was 1.46(θ=0.0) for marker DXS1060,1oeated at Xp22.3,and the two-point and multipoint non-parametric linkage analysis were significant (all at P＞0.05).Conclusions The ND5 A12340G and ND1 G3635A mutations coexist in this LHON family,and the ND5 A12340G mutation is a newly reported mutation.There is no evidence for an X-linked modifiers loci in this Chinese LHON family.

Gene mapping in Avellino corneal dystrophy pedigree / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To point the susceptible gene in Avellino corneal dystrophy family with autosomal dominant inheritance. ●METHODS: Genomic DNA was extracted from the peripheral blood samples of all individuals of the pedigree. Several microsatellite makers were selected for gene scan in the hot regions of mutation. Linkage analysis was carried out using a Linkage software package. The haplotype data were processed using Cyrillic software to define the region of the disease gene. ●RESULTS: ln our pedigree, significant evidence of linkage was obtained at marker D5S396 and D5S393 [LOD score (Z)=3. 01, recombination fraction (θ)=0. 00]. The haplotype analysis of our pedigree was located between the microsatellite markers D5S808 and D5S638. ●CONCLUSION:The pathogenic gene of the Avellino corneal dystrophy pedigree is traced to a 11. 2 cM region in the chromosome 5q.

PKD2 mutation in an Iranian autosomal dominant polycystic kidney disease family with misleading linkage analysis data

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic renal disorder caused by mutation in 2 genes PKD1 and PKD2. Thus far, no mutation is identified in approximately 10% of ADPKD families, which can suggest further locus heterogeneity. Owing to the complexity of direct mutation detection, linkage analysis can initially identify the responsible gene in appropriate affected families. Here, we evaluated an Iranian ADPKD family apparently unlinked to both PKD1 and PKD2 genes. This is one of the pioneer studies in genetic analysis of ADPKD in Iranian population. METHODS: Linkage reanalysis was performed by regenotyping of flanking microsatellite markers in 8 individuals of the ADPKD family. Direct mutation analysis was performed by Sanger sequencing. RESULTS: Mutation analysis revealed a pathogenic mutation (c.1094+1G>A) in the PKD2 gene in the proband. Analyzing 2 healthy and 4 clinically affected members confirmed the correct segregation of the mutation within the family and also ruled out the disease in 1 suspected individual. Misinterpretation of the linkage data was due to the occurrence of 1 crossing over between the PKD2 intragenic and the nearest downstream marker (D4S2929). Homozygosity of upstream markers caused the recombination indistinguishable. CONCLUSION: Although analysis of additive informative polymorphic markers can overcome the misleading haplotype data, it is limited because of the lack of other highly polymorphic microsatellite markers closer to the gene. Direct mutation screening can identify the causative mutation in the apparently unlinked pedigree; moreover, it is the only approach to achieve the confirmed diagnosis in individuals with equivocal imaging results.

Prenatal genetic diagnosis of retinoblastoma – clinical correlates on follow‑up.

Retinoblastoma is the most common malignant intraocular tumor in pediatric age group if undetected leads to ocular mortality. Prenatal diagnosis is an emerging technology to detect fatal diseases in utero such that subsequent management is planned to reduce the ocular morbidity. We describe a case demonstrating the importance of prenatal diagnosis in a child with a strong family history of retinoblastoma and importance of a long‑term clinical follow‑up in these cases.

Application of genetic methods in family-based association study of congenital heart disease / 国际儿科学杂志

Congenital heart disease (CHD) is the most common survivable birth defect in newborns.Pathogenesis of CHD is thought to be associated with environmental and hereditary factors.However,the etiology of most CHD remains unclear.Familial resurgence presents a classic pattern of CHD and data from reviews showed a higher incidence rate in first-degree relatives.Analysis of large multigenerational families could improve the identification of numerous genes and inheritance model in CHD patients.Recent genetic breakthroughs allowed specific evaluation of genetic abnormalities in large families with CHD patients.Next-generation sequencing technologies,genetic linkage analysis and candidate gene analysis have all been applied in the research of family-based CHD.With the development of genetic research technologies, analyses of nuclear famihies or distantly corresponding sporadic cases have generated more progress in CHD studies.Thus, this review will focus on the application of genetic methods in family-based association study of congenital heart disease.

Linkage study of DFNB3 responsible for hearing loss in human.

BACKGROUND: Hearing disorders represent a significant health problem worldwide. Recessive inherited cases of the deafness are more prevalent in Pakistan due to consanguineous marriages. Deafness caused by DFNB3 is due to mutation in the gene MYO XVA and its prevalence among Pakistani population is about 5%. MATERIALS AND METHODS: Families with at least two or more individual affected with deafness were selected from different areas of District Okara of Pakistan. Six consanguineous families of different ethnic groups having deaf individuals were studied. All these families had three or more deaf individuals in either two or more sib ships. Family history was taken to minimize the chances of other abnormalities. Pedigrees drawn by using Cyrillic software (version 2.1) showed that all the marriages were consanguineous and the families have recessive mode of inheritance. Three STR markers were selected and amplified on all the samples of six families through PCR. The PCR products were then genotyped on non denaturing polyacrylamide gel electrophoresis (PAGE). Haplotypes were constructed to determine the pattern of inheritance and also to determine whether a family was linked or unlinked with known DFNB3 locus. RESULTS: One out of six families showed linkage to the DFNB3 while rest of the families remained unlinked. Carriers of deafness genes were identified and information was provided to the families on request. CONCLUSION: Knowledge about the genetic causes of deafness provide insight into the variable expression of genes involved in this hereditary problem and may allow the prediction and prevention of associated health problems.

Advances in molecular genetic study of primary open angle glaucoma / 中华实验眼科杂志

Primary open angle glaucoma (POAG) is a group of disorders characterized by loss of retinal ganglion cells (RGCs) associated with optic nerve degeneration and visual field damage.With the application of molecular biology in ophthalmology,at least 20 chromosome loci have been identified to be linked to POAG.Only 3 causative genes were identified from these loci,i.e.myocilin (MYOC),optineurin (OPTN) and WD repeat domain 36 (WDR36),which altogether account for less than 10％ of POAG.Only a portion of POAG Complies with Mendelian inheritance,and a considerable fraction results from a large number of variants in multiple genes,each contributing less effects.The main technological approaches include family linkage analysis,genome-wide scan,casecontrol association study,etc.Association studies found at least 16 genes to be related to POAG,but reports on glaucoma-causing effects of these genes are conflicting.In this article,we reviewed the POAG related genes,especially the four well known causative genes of MYOC,OPTN,WDR36,and CA V1/CA V2,in terms of their locations,structures,functions,and mutations.

A high resolution genetic mapping of the faded (fe) gene to a region between D10mit156 and D10mit193 on mouse chromosome 10 / 한국실험동물학회지

The C57BL/6J-fe/fe mouse is a coat color mutant. The coat color of the homozygote mouse becomes progressively lighter with advancing age. The faded gene (fe) of C57BL/6J-fe/fe was mapped in a 2.0 cM distal to D10mit191 by our group. To make a high-resolution map, we used the Korean wild mouse (KWHM) for a backcross panel, which was captured in 1995 and has been maintained as an inbred line by our laboratory. In the inter-specific backcross panel (N=400), the fe gene was mapped to 1.0 cM distal to D10mit156. The gene order was defined: centromere -D10mit3/85 (1.3+/-0.6 cM)-D10mit155 (1.3+/-0.6 cM)-D10mit191 (2.0+/-0.7 cM)-D10mit156 (1.0+/-0.5 cM)-fe-D10mit193 (1.3+/-0.6 cM)-D10mit54 (1.0+/-0.5 cM)-D10mit44 (8.5+/-1.4 cM)-D10mit42 (10.0+/-1.5 cM). The measured distance between D10mit191 and D10mit 44 differed in both inter-specific (DBA/2) and intra-specific (KWHM) backcross panels (14.2 vs 13.8 cM). Taken together, our high-resolution linkage map of the fe locus from an intra-specific backcross panel will provide a good entry point to isolate the fe gene.

Compound Heterozygosity for Two Novel SLC26A4 Mutations in a Large Iranian Pedigree with Pendred Syndrome

OBJECTIVES: The aim of this study was to detect the genetic cause of deafness in a large Iranian family. Due to the importance of SLC26A4 in causing hearing loss, information about the gene mutations can be beneficial in molecular detection and management of deaf patients. METHODS: We investigated the genetic etiology in a large consanguineous family with 9 deaf patients from Fars province of Iran with no GJB2 mutations. Initially, linkage analysis was performed by four DFNB4 short tandem repeat markers. The result showed linkage to DFNB4 locus. Following that, DNA sequencing of all 21 exons, their adjacent intronic sequences and the promoter of SLC26A4 was carried out for mutation detection. RESULTS: Two novel mutations (c.863-864insT and c.881-882delAC) were identified in exon 7 of the gene, in both homozygous and compound heterozygous state in patients. CONCLUSION: Our results supported the importance of the SLC26A4 mutations in the etiology of hearing loss among the Iranian patients and therefore its mutation screening should be considered after GJB2 in the molecular diagnostics of hearing loss, especially when enlarged vestibular aqueduct or goiter is detected.

The study of gene GJB2/DFNB1 causing deafness in humans by linkage analysis from district Peshawar.

Families with at least 2 or more individuals having hereditary hearing loss were enrolled from different areas of Khyber Pakhtoonkhwa, mainly from district Peshawar. Detailed history was taken from each family to minimize the presence of other abnormalities and environmental causes for deafness. Families were questioned about skin pigmentation, hair pigmentation, and problems relating to balance, vision, night blindness, thyroid, kidneys, heart, and infectious diseases like meningitis, antibiotic usage, injury, and typhoid. The pedigree structures were based upon interviews with multiple family members, and pedigrees of the enrolled families were drawn using Cyrillic program (version 2.1). All families showed recessive mode of inheritance. I studied 8 families of these 10. For linkage analyses, studies for DFNB1 locus, 3 STR markers (D13S175, D13S292, and D13S787) were genotyped using polyacrylamide gel electrophoresis (PAGE) and haplotypes were constructed to determined, linkage with DFNB1 locus. From a total of 8 families, a single family-10 showed linkage to DFNB1 locus.

Linkage analysis and mutation screening of candidate gene in a Han Nationality family with autosomal dominant retinitis pigmentosa / 中华实验眼科杂志

BackgroundRetinitis pigmentosa (RP) has the genetic and phenotype heterogeneity.To determine the disease-causing gene is a foundation of gene therapy.Objective This study was to localize the pathogenic gene and screen the gene mutation associated with Han Nationality autosomal dominant retinitis pigmentosa (ADRP) in a Chinese family.MethodsTwenty-one families enrolled this study,including 12 patients with ADRP and 9 individuals with normal phenotype.Perimetry,fundus examination,electrooculogram ( EOG ) and electroretinogram (ERG) were performed in 12 patients.Genetic linkage analysis was performed on the subjects in all known genetic loci related to ADRP with a panel of microsatellite markers.Subsequently,the mutation screening of rhodopsin gene was screened by direct DNA sequencing.This study was approved by Ethic Committee of Zhongnan Hospital of Wuhan University.Informed consent was obtained from each subject.ResultsThe fundus appearance of the proband was in accordance with the ADRP,and the EOG and ERG showed undetectable.Contractive visual field also was exhibited in the proband.Linkage analysis showed that the maximum logarithm of the odds(LOD) score reached 3.6671 at marker D3S1292 at recombination fraction θ =0.0.The results of direct DNA sequencing revealed a C→ G transversion mutation at codon 53 in exon 1 of rhodopsin gene,which resulted in a proline to arginine change (Pro53Arg) in 12 patients.However,no similar mutation was found in the unaffected members of this family.ConclusionsThe missence mutation Pro53Arg in rhodopsin gene cosegregate with the RP disease.It is determined to be a pathogenic factor of this ADRP family.

Molecular investigation of mental retardation locus gene PRSS12 by linkage analysis.

The present study was carried out to determine the prevalence of families having mental retardation in Pakistani population. We enrolled seven mentally retarded (MR) families with two or more affected individuals. Family history was taken to minimize the chances of other abnormalities. Pedigrees were drawn using the Cyrillic software (version 2.1). The structure of pedigrees shows that all the marriages are consanguineous and the families have recessive mode of inheritance. All the families were studied by linkage analysis to mental retardation locus (MRT1)/gene PRSS12. Three STR markers (D4S191, D4S2392, and D4S3024) in vicinity of mental retardation (MR) locus (MRT1)/gene PRSS12 were amplified on all the sample of each family by PCR. The PCR products were then genotyped on non denaturing polyacrylamide gel electrophoresis (PAGE). The Haplotype were constructed to determine the pattern of inheritance and also to determine that a family was linked or unlinked to gene PRSS12. One out of the seven families was potentially linked to gene PRSS12, while the other six families remain unlinked.

Mapping of the Faded (fe) Gene to a Region between D10mit191 and D10mit44 on Mouse Chromosome 10 / 한국실험동물학회지

The faded mouse is a coat color mutant that shows faded coat color and age-related loss of pigmentation. This mutation is transmitted by an autosomal recessive gene with 100% penetrance. In the present study, we carried out linkage analysis of the faded (fe) gene using intra-specific backcross panels. Affected faded mice were carefully confirmed by their faded coat color at about 4 weeks of age. In the intra-specific backcross between faded and CBA mice (n=198), the fe gene was mapped to a region 2.1 cM distal to D10mit191. Therefore, the gene order was defined as follows: centromere-D10mit51 (12.4+/-2.4 cM)-D10mit191 (2.1+/-1.0 cM)-fe-D10mit44 (13.3+/-2.4 cM)-D10mit42 (14.4+/-2.5 cM). This linkage map of the fe locus will provide a good entry point to isolate the fe gene. Since the faded mouse has pigmentary abnormalities, this mutant may be a useful model for studies of pigmentary abnormalities in humans.

Linkage analysis of one Chinese family with autosomal dominant congenital cataract / 中华实验眼科杂志

Background About one third of congenital cataract is associated with inheriting factor.The inherited heterogeneity has been found in congenital cataract.To seek the pathogenic gene is essential for the gene therapy. Objective Present study was to map and identify the causal gene for autosomal dominant congenital cataract (ADCC) in a Chinese family. Methods The clinical features of all affected members in this family were examined.Blood samples were collected from eleven family members for genetic linkage analysis.Polymorphic microsatellite markers were selected from the regions which harbor all known loci linked with ADCC.Universal fluorescent-labeled M13 primer was used in linkage analysis.Direct genomic sequencing was used to evaluate the candidate gene for example CRYBB2 gene.This study followed Helsinki Declaration and was proved by Tianjin City Ethic Committee.Written informed consent was obtained from each SUbject before any medical procees. Results The maximum two-point LOD score of 1.20 was obtained for marker D22S315 (θ=0).The LOD score of 0.6 was obtained for marker D16S3068.No mutation in all exons of CRYBB2 gene was found in the family. Conclusion CRYBB2 gene associated with ADCC was excluded from the family.A genome-wide linkage screening should be conducted.Genotyping with microsatellite markers using Universal fluorescent-labeled M13 primer can decrease the cost and obtain the same result.

Directed Causal Network Construction Using Linkage Analysis with Metabolic Syndrome-Related Expression Quantitative Traits

In this study, we propose a novel, intuitive method of constructing an expression quantitative trait (eQT) network that is related to the metabolic syndrome using LOD scores and peak loci for selected eQTs, based on the concept of gene-gene interactions. We selected 49 eQTs that were related to insulin resistance. A variance component linkage analysis was performed to explore the expression loci of each of the eQTs. The linkage peak loci were investigated, and the "support zone" was defined within boundaries of an LOD score of 0.5 from the peak. If one gene was located within the "support zone" of the peak loci for the eQT of another gene, the relationship was considered as a potential "directed causal pathway" from the former to the latter gene. SNP markers under the linkage peaks or within the support zone were searched for in the database to identify the genes at the loci. Two groups of gene networks were formed separately around the genes IRS2 and UGCGL2. The findings indicated evidence of networks between genes that were related to the metabolic syndrome. The use of linkage analysis enabled the construction of directed causal networks. This methodology showed that characterizing and locating eQTs can provide an effective means of constructing a genetic network.

Exclusive Gene Mapping in an Congenital Hyperthyroidism Family / 华中科技大学学报(医学版)

Objective Gene linkage would be processed in order to make sure if an autosomal dominant congenital hyperthyroidism family has genetic linking relationship with the known hyperthyroidism disease genes,TSHR or THRB.Methods Microsatellite marked gene linkage was done with the use of three microsatellite markers,D14S74,D3S2338 and D3S1266,whose chromosomal locations were very close to TSHR or THRB gene,and the results were analyzed by Genemapper 3.5 Software.Results LOD scores of the three markers were all less than 1,revealing that there were no linking relationships between TSHR or THRB gene and this hyperthyroidism family,further reflecting this family might have a new disease gene other than TSHR and THRB.Conclusion There might be new disease genes responsible for autosomal dominant congenital hyperthyroidism.

Genetic and Audiological Characteristics of a Chinese Family with Autosamal Dominant Hereditary Non-syndromic Low-frequency Sensorineural Hearing Loss / 听力学及言语疾病杂志

Objective To investigate the phenotype and genetic characteristics of a Chinese family with an autosomal-dominant inherited sensorineural hearing loss.Methods A Chinese pedigree associated with an autosomal-dominant inherited low-frequency sensorineural hearing loss (LFSNHL) was investigated.After obtaining informed consent from all study participants medical and audiological examination were used to rule out any syndromic hearing impairment.Five patients were tested with DPOAE and ABR,while two patients were tested with vestibular function and computed tomography scan of the temporal bone to exclude auditory neuropathy and other possible aural disorders.Twenty-one loci and twenty-three genes of DFNA screening had been done by using microsatellite markers and linkage analysis.Results Proband of the family had been diagnosed with low-frequency sensorineural hearing loss.A Chinese family BJ-L046 with non-syndromic autosomal dominant hearing loss was ascertained.Hearing impairment in the affected members in family BJ-L046 occured from 10 to 20 years of age and mainly affected the low frequencies,causing an upsloping audiogram.Higher frequencies were getting involved with increasing age,thus causing a flat-type audiogram.No positive result was found in twenty-one loci and twenty-three genes of DFNA screening.Conclusion A Chinese family with late-onset low-frequency sensorineural hearing loss was clinically studied.No positive result was found by linkage analysis,and twenty-one loci and twenty-three genes of DFNA were preliminary excluded.

Genetic Factors in Bronchial Asthma / 대한내과학회지

Bronchial asthma is a chronic inflammatory disease of the airways in which there isincreased responsiveness to various stimuli, resulting in wheezing, shortness of breath, and coughing. Interactions between environmental and genetic factors may modify both the susceptibility to and severity of the disease. In recent years, much progress has been made in improving our understanding of the genetic basis of bronchial asthma, which has led to the identification of several genetic factors. This review is an update of genetic studies of bronchial asthma and recent findings.