Pathogenesis Of Two Genetic Diseases

Study on the pathogenesis of a family with mental retardationBackground and purposeIntellectual Disability(ID)is one of the most common neuropsychiatric disorders in children and adults.It refers to diseases with significant cognitive impairment and social adaptability at the stages of development(before the age of 18)The intelligence level(The score less or equal than 70)ID also known as mental retardation,mental retardation(Mental Retardation,MR),mostly over 5 years of children,because the IQ(IQ)has been already reliable and stable.Developmental delay(DD)refers to infants and preschool children who are under 5 years of age.Mental retardation(MR)refers to cognitive and social adaptation before the age of 18.The 25%?50%MR is due to genetic factors,including chromosomal abnormalities,gene copy number abnormalities and individual gene mutations.Method:Collect all the members of the peripheral venous blood,phenol/chloroform extraction of DNA,collecting members of the family members of the clinical data.The chromosomal karyotype analysis was performed using peripheral blood lymphocytes to analyze whether the patient's chromosomes were abnormal.The whole genome deletion or replication of some patients was detected by microarray comparison genomic hybridization(arrary CGH).Compared to the OMIM database,according to the database of genetic information to select the functional gene.Using the NCBI and oligo7 software to design primers for 16 genes screened on OMIM,the CDS region of the human mRNA of the corresponding gene was amplified.According to GeneCards,the expression levels of these 16 genes in different tissues were found.RNA from human blood or other tissues was extracted with TRIZOL and reverse transcribed into cDNA.The above gene was cloned into the expression vector PCS2,the single enzyme was linear,and the mRNA was synthesized in vitro using the SP6 kit.The two groups were introduced into the zebrafish fertilized eggs by microinjection.After 4.25 hpf,the zebrafish was observed with a stereomicroscope and photographed.The width and body length of the zebrafish were measured in a computer.difference between.Differentiated groups were individually introduced into zebrafish fertilized eggs to find genes that led to changes in the size of the zebrafish.Result:Chromosome karyotype analysis was performed on some members of the family(patients and normal subjects),and the results of the karyotype analysis were all normal.(IV-10)and other similar symptoms(IV-14),the chromosome 2 appeared 2.2Mb 2q terminal deletion,and chromosome 4 appeared 4.6Mb 4p terminal duplication.The phenotype is opposite,the stature is short,the development of slow IV-18,chromosome 2 shows 2.2Mb 2q terminal duplication,chromosome 4 shows 4.6Mb 4p terminal deletion.The zebrafish overexpression mRNA was found to be less than the DEPC group in the zebrafish head width compared with the injection of STK25 and SEPT2,PPP1R7 and OTOS.Conclusion:According to the research,the candidate region of the pathogenic gene was located at 2.2Mb2q terminal and 4.6Mb4p terminal through chromosome karyotype analysis and comparative genomic hybridization technique.Among them,Wolf-Hirschhom showed growth retardation and mental retardation.Overexpression the genes of chromosome 2 to Zebrafish,the STK25 and SEPT2,PPP1R7 and OTOS had an effect on the width of zebrafish head.A novel OCRL mutation causes Lowe syndrome in a Chinese familyBackground and Purpose:Lowe syndrome(oculo-cerebro-renal syndrome)is a rare X-linked recessive hereditary disease characterized by congenital cataracts,mental retardation,and proximal renal tubular dysfunction.In this study,we investigated the OCRL gene mutation in a Chinese Han family with Lowe syndrome and study the pathogenesis of the mutation with OCRL gene.Methods:Clinical manifestations with eyes,brain and kidneys were used for clinical diagnosis.Peripheral blood was taken from the family members.Polymerase chain reaction(PCR)was used for amplifying the OCRL gene and then analyzed with Sanger sequencing.The novel mutation of the pathogenesis was analyzed by bioinformatics,real-time PCR,subcellular localization and Western blot.Results:Proband and his brother were diagnosed with Lowe syndrome.The Sanger sequencing showed a novel mutation c.13 83 del A in exon 14 of the OCRL gene.Their parents had no obvious clinical symptoms,only the mother carried the mutation site.The frameshift mutation generated a truncated protein that was expressed in transfected Human embryonic kidney(HEK)293T cells.Subcellular localization experiments showed that GFP-tagged of wild-type and mutant OCRL protein were located on the cytoplasm of HEK-293T cells.Western blot analyzed that the protein expression of Co-transfection in HEK293T cells with mutant expression plasmids was significantly lower than wild type protein.Conclusion:Our study suggests that the novel frameshift mutation(c.1383delA)of OCRL gene leads to a truncated protein and involves in Lowe syndrome pathogenesis with loss of function of protein and Nonsense-Mediated mRNA Decay.These findings expand the mutation spectrum of OCRL gene,and provide theoretical basis for the treatment and genetic counseling of the Lowe syndrome family.