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Objective:To identify disease-causing variation in a Chinese family with Axenfeld-Rieger syndrome (ARS) through the analysis of clinical symptoms and hereditary information.Methods:The method of pedigree investigation was adopted.A Chinese ARS family including 15 family members of 3 generations was recruited in the Second Affiliated Hospital of Harbin Medical University in 2018.There were 3 patients in the family.The family history and clinical data were collected.Ophthalmic and general examinations were carried out in all the members included.DNA and RNA were extracted from collected peripheral venous blood samples of 2-5 ml from each member.Whole exome sequencing was used to screen the variations in the proband.Suspected variations screened through searching population databases and bioinformatics analysis were verified by Sanger sequencing and real-time quantitative PCR.Conservation analysis and deleteriousness prediction of suspected variations were conducted.The pathogenecity of candidate rare variations were evaluated according to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines.This study followed the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Harbin Medical University (No.KY2019-231).Written informed consent was obtained from each subject or custodian prior to entering the study cohort.Results:The 3 patients all had typical ARS clinical features in eyes, teeth and umbilicus, and carried the same heterozygous variant, c.525delC (p.Asp175Glufs *) in the PITX2 gene, which were not found in other members, indicating co-segregation.The relative expression of PITX2 mRNA was 0.672±0.063 in the patients, which was significantly lower than 1.015±0.179 in the healthy controls ( t=8.847, P<0.001).This variant was not recorded in dbSNP, 1000G, gnomeAD, ExAC, Korea1K and EVS databases, and it was labelled as deleterious by MutationTaster.The affected conservative amino acid sequences were found in 9 species.The variant was determined as pathogenic according to the ACMG standards and guidelines. Conclusions:The c.525delC (p.Asp175Glufs *) mutation of PITX2 gene is pathogenic in the pedigree.This is the first time that this mutation has been reported in Chinese family with ARS.
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@#AIM: To analyze the clinical characteristics of patients with Peters' anomaly(PA)in Chinese, and to study the variation of PITX2 and PAX6 genes in patients with PA, so as to provide basis for clinical diagnosis and pathogenesis of this rare ophthalmopathy.<p>METHODS: Fifteen patients with PA were selected from 2016 to 2019 in Changzhou No. 2 People's Hospital and Changzhou No. 3 People's Hospital, and the detailed clinical data were collected. Genomic DNA was prepared from venous leukocytes after obtaining the consent of the patients and their family members. The coding regions and the flanking exon-intron junctions of the PITX2 and PAX6 genes were amplified by polymerase-chain reaction(PCR)and subsequently analyzed by direct sequencing. Variations detected were further evaluated in any unaffected member and 80 normal controls by HA-SSCP. Analyzing and comparing the mutation of PITX2 and PAX6 genes and the related phenotypes in Chinese patients with PA.<p>RESULTS:Sequence analysis of the PITX2 gene revealed one novel mutation c.296delG(P.R99fsx56)in fifteen patients with PA. Nucleotide sequence analysis showed that this mutation led to the functional abnormal of this gene. The clinical characteristics of the mutant patient were analyzed, the right eye of the patient was diagnosed as Axenfeld-Rieger syndrome(ARS), and the left eye was diagnosed as Peters'anomaly. However, the mutation was not found in the family members of the patient's parents and unrelated normal controls, and therefore it was a de novo mutation. No mutation was found in PAX6 gene mutation screening.<p>CONCLUSION: A novel PITX2 gene mutation was detected in 15 patients with PA, which was the first report of PITX2 gene mutation in a patient with Peters'anomaly complicated with ARS in China. The results enrich the mutation spectrum of PITX2 gene and further clarify the clinical characteristics of PA complicated with ARS. All these will be useful foundations for clinical diagnosis and pathogenesis. Furthermore, it enriches our knowledge of genotype-phenotype relationship of PA. In addition, our results may provide basis for the functional and genomic study of the pathogenesis of the disease in the future.
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Objective To screen the neonatal malrotation with PITX2 gene exon 2 and 5 gene mutation through the study on molecular genetics.Methods From January 201 2 to December 201 4,1 5 cases of neonatal malro-tation infants(experimental group)and 25 healthy newborn infants(healthy control group)were selected as the research subjects from the First Affiliated Hospital of Shihezi University Medical College.The experimental group included 1 5 ca-ses of volvulus,4 cases of volvulus with duodenal atresia and 3 cases of volvulus with jejunal atresia.The clinical fea-tures were recorded and 3 mL peripheral venous blood from each subject was collected.After ethylenediamine tetraacetic acid (EDTA)anticoagulation,genomic DNA was extracted.Polymerase chain reaction (PCR)was used to amplify the exon 2 and exon 5 of PITX2 gene,and the direct sequencing method was used to screen whether there were mutations in these 2 loci.Results According to the findings of the matching gene,PITX2 gene exon 2 and exon 5 mutations were not detected in 15 cases with intestinal malrotation of the experimental group and 25 healthy newborns in the healthy control group.Conclusions Polymorphisms is not detected in PITX2 gene exon 2 and exon 5 in small groups of newborn,but this does not exclude the possibility the gene caused newborns suffering from intestinal malrotation by other means.