BACKGROUNDWaardenburg syndrome type I (WS1) is an autosomal dominant disorder characterized by sensorineural hearing loss, pigmental abnormalities of the eye, hair and skin, and dystopia canthorum. The gene mainly responsible for WS1 is PAX3 which is involved in melanocytic development and survival. Mutations of PAX3 have been reported in familiar or sporadic patients with WS1 in several populations of the world except Chinese. In order to explore the genetic background of Chinese WS1 patients, a mutation screening of PAX3 gene was carried out in four WS1 pedigrees.

METHODSA questionnaire survey and comprehensive clinical examination were conducted in four Chinese pedigrees of WS1. Genomic DNA from each patient and their family members was extracted and exons of PAX3 were amplified by PCR. PCR fragments were ethanol-purified and sequenced in both directions on an ABI_Prism 3100 DNA sequencer with the BigDye Terminator Cycle Sequencing Ready Reaction Kit. The sequences were obtained and aligned to the wild type sequence of PAX3 with the GeneTool program.

RESULTSTwo nonsense PAX3 mutations have been found in the study population. One is heterozygous for a novel nonsense mutation S209X. The other is heterozygous for a previously reported mutation in European population R223X. Both mutations create stop codons leading to truncation of the PAX3 protein.

CONCLUSIONSThis is the first demonstration of PAX3 mutations in Chinese WS1 patients and one of the few examples of an identical mutation of PAX3 occurred in different populations.

Codon, Nonsense ; Female ; Humans ; Male ; PAX3 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Waardenburg Syndrome ; genetics

OBJECTIVETo investigate the mutation of PAX6 gene in a Chinese family affected with congenital aniridia.

METHODSBlood samples were drawn from family members, and DNA was analyzed by direct sequencing.

RESULTSA heterozygous mutation (c.151 G>A) was identified in the PAX6 gene in the proband and other patients from the family. The same mutation was not found among unaffected family members and 160 unrelated healthy controls.

CONCLUSIONA novel mutation in the PAX6 gene has been identified in a Chinese family affected with aniridia.

Aniridia ; genetics ; Eye Proteins ; genetics ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Mutation ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Repressor Proteins ; genetics

OBJECTIVETo identify potential mutation of the PAX6 gene in a family affected with congenital aniridia from northeastern China.

METHODSTwo patients were collected from the family and underwent full ophthalmologic examinations. Genomic DNA was extracted from all family numbers and 100 healthy controls. The coding regions and flanking sequence of the PAX6 gene were amplified by PCR amplification and subjected to bidirectional DNA sequencing.

RESULTSA nonsense mutation (c.718 C>T) was identified in exon 9 in both patients but not in other unaffected families or the 100 healthy controls. However, obvious difference was noted in the phenotype between the two patients. One of the patient has presented irregular cornea, which was infrequently reported.

CONCLUSIONA c.718C>T transitional mutation has been found to underlie the aniridia, which showed an autosomal dominant inheritance pattern in this northeastern Chinese family.

Aniridia ; genetics ; Eye Proteins ; genetics ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Mutation ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Repressor Proteins ; genetics

BACKGROUNDMutations in PAX6 gene have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. However, there is no study to do genetic analysis of aniridia, although there are several case reports in China. Here, we describe a mutation analysis of PAX6 in a large Chinese family with aniridia.

METHODSGenomic DNA from venous blood samples was prepared. Haplotype analysis was performed with two genetic markers (D11S904 and D11S935). Fourteen exons of the PAX6 gene were amplified from genomic DNA. Polymerase chain reaction (PCR) products of each exon were analysed by single strand conformational polymorphism (SSCP). The PCR products having an abnormal pattern were sequenced to confirm the mutation.

RESULTSSignificant evidence for allele sharing in affected patients was detected suggesting that PAX6 mutation links to aniridia in this family. An extra band corresponding to exon 9 in PAX6 was found by single strand conformational polymorphism analysis in all the aniridia patients in this family, but not detected in the unaffected members. A mutation of C to T was detected by sequencing at the nucleotide 1080 that converts the Arg codon (CGA) to the termination codon (TGA).

CONCLUSIONSAniridia is caused by a nonsense mutation of PAX6 gene in the large Chinese kindred. Genetic test is important to prevent the transmission of aniridia to their offsprings in the kindred by prenatal diagnosis.

Aniridia ; genetics ; Eye Proteins ; genetics ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Mutation ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; Pedigree ; Repressor Proteins ; genetics

OBJECTIVETo perform genetic analysis for 7 patients with Waardenburg syndrome.

METHODSPotential mutation of MITF, PAX3, SOX10 and SNAI2 genes was screened by polymerase chain reaction and direct sequencing. Functions of non-synonymous polymorphisms were predicted with PolyPhen2 software.

RESULTSSeven mutations, including c.649-651delAGA (p.R217del), c.72delG (p.G24fs), c.185T>C (p.M62T), c.118C>T (p.Q40X), c.422T>C (p.L141P), c.640C>T (p.R214X) and c.28G>T(p.G43V), were detected in the patients. Among these, four mutations of the PAX3 gene (c.72delG, c.185T>C, c.118C>T and c.128G>T) and one SOX10 gene mutation (c.422T>C) were not reported previously. Three non-synonymous SNPs (c.185T>C, c.128G>T and c.422T>C) were predicted as harmful.

CONCLUSIONGenetic mutations have been detected in all patients with Waardenburg syndrome.

Adolescent ; Child ; Female ; Humans ; Male ; Microphthalmia-Associated Transcription Factor ; genetics ; Mutation ; PAX3 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Polymorphism, Single Nucleotide ; SOXE Transcription Factors ; genetics ; Waardenburg Syndrome ; genetics

Aniridia ; genetics ; Base Sequence ; China ; Codon, Nonsense ; genetics ; DNA Mutational Analysis ; methods ; Eye Proteins ; genetics ; Female ; Frameshift Mutation ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Infant ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Pedigree ; Repressor Proteins ; genetics

OBJECTIVEThe PAX6 gene encodes a transcriptional regulator involved in oculogenesis and other developmental processes such as aniridia, a congenital condition characterized by the underdevelopment of the iris of eyes. The function of the PAX6 gene in these two conditions is still poorly defined. The purpose of this study is to identify the mutation of the PAX6 gene in a Chinese family with aniridia.

METHODSTwo aniridia patients collected from the family underwent full ophthalmologic examination. Genomic DNA was prepared from venous leukocytes of the two patients and five healthy individuals in the family, and 100 unrelated healthycontrols. Exons 4-13 and their immediate flanking sequences of the PAX6 gene was analyzed by PCR amplification, direct sequencing, and single-strand conformation polymorphism(SSCP).

RESULTSThe sequencing result revealed a novel PAX6 mutation in the two patients. It was a heterozygous mutation (IVS10+1G>A) at the boundary of exon 10 and intron 10. The mutation was also detected by SSCP analysis. It was not detected in the healthy relatives and unrelated controls.

CONCLUSIONAniridia is an autosomal dominant inheritable disease. A novel PAX6 gene mutation has been identified in the Northeastern Chinese family with aniridia. The genetic analysis suggested that this novel mutation in the PAX6 gene is capable of causing the classic aniridia phenotype.

Aniridia ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Eye Abnormalities ; genetics ; Eye Proteins ; genetics ; Heterozygote ; Homeodomain Proteins ; genetics ; Humans ; Mutation ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Pedigree ; Repressor Proteins ; genetics

OBJECTIVETo identify the mutation in the PAX6 gene in a family with congenital aniridia and cataract.

METHODSTotal genomic DNA was extracted from peripheral blood leukocytes of 12 family members including three living affected members and 96 unrelated healthy controls. The coding exons 4-13 of the PAX6 gene with intronic flanking sequences were amplified by polymerase chain reaction (PCR). By comparing sequences of the affected members with that of normal individuals, the disease-causing mutation was detected by direct DNA sequencing.

RESULTSA PAX6 mutation was identified in the 3 patients, which did not exist in the unaffected members and unrelated healthy individuals. The nonsense mutation of C to T was detected at the nucleotide 1143, which converted the Arg codon (CGA) to a stop codon(TGA) (R261X) in exon 10.

CONCLUSIONThe mutation (R261X) detected in the present study is considered to result in the occurrence of congenital aniridia and cataract in the Chinese family.

Amino Acid Sequence ; Aniridia ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Cataract ; congenital ; genetics ; Codon, Nonsense ; Eye Proteins ; genetics ; Homeodomain Proteins ; genetics ; Humans ; Male ; Molecular Sequence Data ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Pedigree ; Repressor Proteins ; genetics

OBJECTIVETo detect potential mutation in a Chinese family where two individuals were affected with hereditary congenital aniridia.

METHODSPeripheral blood samples were taken for genomic DNA extraction. All of the 15 exons of PAX6 gene were amplified with PCR. The product were purified with gel electrophoresis and sequenced.

RESULTSIn both patients, a novel deletion mutation (c.957-958delCA) in exon 13 of the PAX6 gene was identified, which has produced a terminator codon. The same mutation was not found in healthy controls.

CONCLUSIONA c.957-958delCA mutation of PAX6 gene is probably the cause of aniridia in this Chinese family.

Adult ; Aniridia ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Exons ; Eye Proteins ; genetics ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Molecular Sequence Data ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Pedigree ; Repressor Proteins ; genetics ; Sequence Deletion

OBJECTIVETo study the PAX6 gene mutation in a Chinese pedigree with congenital aniridia.

METHODSLinkage analysis was performed to the Chinese family with congenital aniridia using two microsatellite markers D11S904 and D11S935. Analysis of the PAX6 gene mutation was done by direct sequencing of the whole coding region and exon-intron boundaries of the PAX6 gene in all affected and unaffected individuals in the family.

RESULTSThe significant Lod Score of 3.01 was acquired at D11S935. Direct DNA sequence analysis identified a 1080C to T change in exon 9 of the patients, resulting in an Arginine substitution by a stop codon at codon 240 of the PAX6 gene, which was absent in the unaffected individuals in the family and 100 normal controls.

CONCLUSIONOur results indicate that mutation p.Arg240Ter of the PAX6 is the genetic basis of the Chinese family with congenital aniridia.

Adolescent ; Adult ; Aged ; Aniridia ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Codon, Nonsense ; Eye Proteins ; genetics ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Microsatellite Repeats ; Molecular Sequence Data ; PAX6 Transcription Factor ; Paired Box Transcription Factors ; genetics ; Pedigree ; Repressor Proteins ; genetics