Mutation analysis of seven patients with Waardenburg syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform genetic analysis for 7 patients with Waardenburg syndrome.</p><p><b>METHODS</b>Potential 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.</p><p><b>RESULTS</b>Seven 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.</p><p><b>CONCLUSION</b>Genetic mutations have been detected in all patients with Waardenburg syndrome.</p>

Analysis of PAX6 gene mutation in a family affected with congenital aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation of the PAX6 gene in a family affected with congenital aniridia from northeastern China.</p><p><b>METHODS</b>Two 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.</p><p><b>RESULTS</b>A 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.</p><p><b>CONCLUSION</b>A c.718C>T transitional mutation has been found to underlie the aniridia, which showed an autosomal dominant inheritance pattern in this northeastern Chinese family.</p>

Analysis of PAX6 gene mutations in a Chinese family affected with congenital aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mutation of PAX6 gene in a Chinese family affected with congenital aniridia.</p><p><b>METHODS</b>Blood samples were drawn from family members, and DNA was analyzed by direct sequencing.</p><p><b>RESULTS</b>A 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.</p><p><b>CONCLUSION</b>A novel mutation in the PAX6 gene has been identified in a Chinese family affected with aniridia.</p>

DNA methylation in human papillomavirus-infected cervical cells is elevated in high-grade squamous intraepithelial lesions and cancer / 부인종양

OBJECTIVE: DNA methylation has been shown to be a potential biomarker for early cancer detection. The aim of this study was to evaluate DNA methylation profiles according to liquid-based Pap (LBP) test results and to assess their diagnostic value in a Korean population. METHODS: A total of 205 patients with various Papanicolaou test results were enrolled to this study (negative, 26; atypical squamous cells of undetermined significance, 39; low grade squamous intraepithelial lesion, 44; high grade squamous intraepithelial lesion (HSIL), 48; and cancer, 48). DNA methylation analysis of four genes, ADCYAP1, PAX1, MAL, and CADM1, was performed on residual cervical cells from LBP samples using a quantitative bisulfite pyrosequencing method. To evaluate the diagnostic performance of the four methylated genes for cancer detection, receiver operating characteristic (ROC) curves were drawn. Sensitivities and specificities were also tested at cutoffs determined from the ROC curves. RESULTS: Cervical cancer cells showed dramatically increased methylation levels for the four genes analyzed. ADCYAP1 and PAX1 also trended toward elevated methylation levels in HSIL samples, although the levels were much lower than those in cancer cells. The sensitivities of methylated ADCYAP1, PAX1, MAL, and CADM1 for the detection of cancer were 79.2%, 75.0%, 70.8%, and 52.1%, and the specificities were 92.0%, 94.0%, 94.7%, and 94.0%, respectively. Methylated ADCYAP1 and PAX1 demonstrated relatively better discriminatory ability than did methylated MAL and CADM1 (area under the curves 0.911 and 0.916 vs. 0.854 and 0.756, respectively). CONCLUSION: DNA methylation status, especially in the ADCYAP1 and PAX1 genes, showed relatively good specificity, ranging from 90% to 94%. The possible additive and complementary roles of DNA methylation testing with respect to conventional cervical cancer screening programs will need to be validated in prospective population-based studies.

Clinical classification and genetic mutation study of two pedigrees with type II Waardenburg syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular etiology of two pedigrees affected with type II Waardenburg syndrome (WS2) and to provide genetic diagnosis and counseling.</p><p><b>METHODS</b>Blood samples were collected from the proband and his family members. Following extraction of genomic DNA, the coding sequences of PAX3, MITF, SOX10 and SNAI2 genes were amplified with PCR and subjected to DNA sequencing to detect potential mutations.</p><p><b>RESULTS</b>A heterozygous deletional mutation c.649_651delAGA in exon 7 of the MITF gene has been identified in all patients from the first family, while no mutation was found in the other WS2 related genes including PAX3, MITF, SOX10 and SNAI2.</p><p><b>CONCLUSION</b>The heterozygous deletion mutation c.649_651delAGA in exon 7 of the MITF gene probably underlies the disease in the first family. It is expected that other genes may also underlie WS2.</p>

The homeodomain of Eyeless regulates cell growth and antagonizes the paired domain-dependent retinal differentiation function

Pax6 and its Drosophila homolog Eyeless (Ey) play essential roles during eye development. Ey/Pax6 contains two distinct DNA binding domains, a Paired domain (PD) and a Homeodomain (HD). While Ey/Pax6 PD is required for the expression of key regulators of retinal development, relatively little is known about the HD-dependent Ey function. In this study, we used the UAS/GAL4 system to determine the functions of different Ey domains on cell growth and on retinal development. We showed that Ey can promote cell growth, which requires the HD but not the PD. In contrast, the ability of Ey to activate Ato expression and induce ectopic eye formation requires the PD but not the HD. Interestingly, deletion of the HD enhanced Ey-dependent ectopic eye induction while overexpression of the HD only Ey forms antagonizes ectopic eye induction. These studies revealed a novel function of Ey HD on cell growth and a novel antagonistic effect of Ey HD on Ey PD-dependent eye induction. We further show the third helix of the Ey HD can directly interact with the RED subdomain in Ey PD and that deletion of the HD increased the binding of Ey PD to its target. These results suggest that the direct interaction between the HD and the PD potentially mediates their antagonistic effects. Since different Ey splicing forms are expressed in overlapping regions during normal development, we speculate that the expression ratios of the different Ey splice forms potentially contribute to the regulation of growth and differentiation of these tissues.

Expression of carbonic anhydrase IX, PAX2 and PAX8 and their association with clinicopathologic characteristics in renal epithelial tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression of carbonic anhydrase IX (CAIX), PAX2 and PAX8 in different types of renal epithelial tumor and their association with clinicopathologic characteristics.</p><p><b>METHODS</b>Immunohistochemical study by EnVision method was performed in order to assess the expression of CAIX, PAX2 and PAX8 in 155 cases of renal cell carcinoma and 4 cases of metastatic clear cell renal cell carcinoma (CCRCC). Ninety-six cases of non-neoplastic renal parenchymal tissue adjacent to CCRCC, 8 cases of clear cell hepatocellular carcinoma and 2 cases of clear cell hidradenoma were used as controls.</p><p><b>RESULTS</b>CAIX was commonly expressed in CCRCC (94.0%, 63/67), of which 77.8% (49/63) showed strong positivity. CAIX was focally positive in papillary renal cell carcinoma, collecting duct carcinoma and urothelial carcinoma of renal pelvis. It was negative in chromophobe renal cell carcinoma, oncocytoma and adjacent non-neoplastic renal tissue. CAIX was also strongly expressed in the 4 cases of metastatic CCRCC. Focal expression of CAIX was demonstrated in the 8 cases of clear cell hepatocellular carcinoma and 2 cases of clear cell hidradenoma. The expression of CAIX in CCRCC did not correlate with tumor grading, clinical staging and presence of distal metastasis. On the other hand, PAX2 showed positive expression in different types of renal epithelial tumor, clear cell hepatocellular carcinoma and clear cell hidradenoma in various degrees. In contrast, PAX8 was commonly expressed in all types of renal epithelial tumor, with the exception of urothelial carcinoma of renal pelvis. PAX8 was not expressed in clear cell hepatocellular carcinoma and clear cell hidradenoma. Regarding diagnosis of CCRCC, CAIX demonstrated high sensitivity and specificity. PAX2 showed high specificity but low sensitivity. PAX8 was sensitive and specific in the diagnosis of renal epithelial tumor.</p><p><b>CONCLUSIONS</b>CAIX is a useful immunohistochemical marker with high specificity and sensitivity in distinguishing CCRCC from other types of renal epithelial tumor and clear cell tumors of non-renal origin. PAX2 is a marker with high sensitivity and low specificity for diagnosis of renal epithelial tumors. PAX8 is typically expressed in renal epithelial tumors. The combined detection of CAIX, PAX2 and PAX8 is useful in the diagnosis and differential diagnosis of renal epithelial tumors.</p>

Impact of Pax-8 gene interference on mitochondrial function and cardiomyocyte apoptosis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the effects of paired box gene 8 (Pax-8) silencing by RNA interference on mitochondrial function and cardiomyocytes apoptosis.</p><p><b>METHODS</b>The cultured H9C2 (2-1) myocytes were divided into 3 groups: short interference RNA targeting Pax-8 (Pax-8 siRNA) group, non-specific siRNA group as the negative control (NC siRNA), and blank control group (BC siRNA). Fluorescence spectrophotometry was used to detect the activity of caspase-3. RT-PCR was performed to detect mRNA expression of Bcl2 and Bax. The protein expression of Bcl2, Bax and cytoplasm of Cytochrome was examined by Western blot. Changes of ΔΨm were detected by flow cytometry.ΔΨm with JC-1 monomer/polymer ratio was calculated for measuring mitochondrial depolarization proportion.</p><p><b>RESULTS</b>Compared to NC siRNA and BC siRNA group (0.075 ± 0.021, 0.072 ± 0.019), the activity of caspase-3 in Pax-8 siRNA group (0.167 ± 0.012) was significantly increased (P < 0.05); Bcl2 mRNA and protein expression in Pax-8 siRNA group (0.61 ± 0.06, 0.94 ± 0.11) were significantly downregulated compared with NC siRNA group (0.90 ± 0.070, 1.39 ± 0.15) and BC siRNA group (0.94 ± 0.087, 1.49 ± 0.20) (P < 0.05); Bax mRNA and protein expression in Pax-8 siRNA group (1.05 ± 0.10, 1.25 ± 0.12) were markedly upregulated compared with NC siRNA group (0.72 ± 0.03, 0.99 ± 0.12) and BC siRNA group (0.64 ± 0.03, 0.92 ± 0.06), P < 0.05; cytosolic cytochrome expression in Pax-8 siRNA group (0.75 ± 0.14) was significantly upregulated compared with NC siRNA group (0.51 ± 0.06) and BC siRNA group (0.48 ± 0.07) (P < 0.05); JC-1 monomer/polymer ratio in Pax-8 siRNA group (0.163 ± 0.011) was significantly increased compared with NC siRNA group (0.092 ± 0.015) and BC siRNA group (0.072 ± 0.025) (P < 0.05) indicating mitochondrial membrane potential was significantly reduced in Pax-8 siRNA group. Above parameters were similar between NC siRNA group and BC siRNA group (P > 0.05).</p><p><b>CONCLUSION</b>Inhibiting Pax-8 results in enhanced cardiomyocytes apoptosis through the mitochondrial pathway.</p>

Identification of a novel PAX6 mutation in a family with congenital aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutation in a Chinese family where two individuals were affected with hereditary congenital aniridia.</p><p><b>METHODS</b>Peripheral 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.</p><p><b>RESULTS</b>In 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.</p><p><b>CONCLUSION</b>A c.957-958delCA mutation of PAX6 gene is probably the cause of aniridia in this Chinese family.</p>

Absence of mutations in PAX8, NKX2.5, and TSH receptor genes in patients with thyroid dysgenesis / Ausência de mutações nos genes PAX-8, NKX2.5 e receptor de TSH em pacientes com disgenesia tireoidiana

OBJECTIVES: To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. SUBJECTS AND METHODS: Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor (TSHR) gene in those with hypoplasia. RESULTS: In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. CONCLUSION: Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development.

OBJETIVOS: Classificar corretamente as várias formas de DT e depois rastrear por mutações em genes que participam no desenvolvimento da tireoide. SUJEITOS E MÉTODOS: Os pacientes realizaram ultrassonografia, cintilografia e tireoglobulina sérica para o diagnóstico preciso de DT. DNA foi extraído de leucócitos periféricos. Os genes PAX8 e NKX2.5 foram estudados em todos os pacientes e o gene do receptor do TSH (TSHR) foi estudado na hipoplasia. RESULTADOS: Avaliaram-se 27 pacientes sem consanguinidade com DT, dos quais 13 foram diagnosticados com ectopia, 11 com hipoplasia e 3 com atireose. Nenhuma mutação foi detectada nos genes estudados. CONCLUSÃO: Casos esporádicos de DT são provavelmente causados mais por fatores epigenéticos do que por mutações em fatores de transcrição ou genes envolvidos no desenvolvimento tireoidiano.

Mutations in the gene encoding paired box domain (PAX8) are not a frequent cause of congenital hypothyroidism (CH) in Iranian patients with thyroid dysgenesis / As mutações no gene PAX8 não constituem uma causa frequente de hipotireoidismo congênito em pacientes iranianos com disgenesia tiroidiana

OBJECTIVE: Congenital hypothyroidism (CH) may be caused by defects in the thyroid or in one of the stages in the synthesis of thyroid hormones. Thyroid dysgenesis may be associated with mutation in the paired box transcription factor 8 (PAX8) gene. We attempted to screen PAX8 gene mutation in 50 CH patients with thyroid dysgenesis. SUBJECTS AND METHODS: The patients were classified in two groups as agenesis and ectopic based on biochemical and para clinical tests. By employing PCR, Single Strand Conformation Polymorphism (SSCP) and sequencing, exons 3 to 12 of PAX8 gene with their exon-intron boundaries were studied. RESULTS: No mutation was found in these patients in any of the exons. CONCLUSION: Our results, once again, indicate that the PAX8 mutation rate is very low and can only explain a minority of the cases. Therefore, it is highly needed to further investigate the genes controlling development and function of thyroid.

OBJETIVO: O hipotireoidismo congênito (HC) pode ser causado por defeitos na formação da tireoide ou em uma das etapas da síntese dos hormônios tireoidianos. A disgenesia da tireoide pode ser associada a mutações no fator de transcrição PAX8. Neste estudo, foram rastreadas mutações no gene PAX8 em 50 pacientes com CH com disgenesia da tireoide. SUJEITOS E MÉTODOS: Os pacientes foram classificados em dois grupos, com agenesia ou com ectopia, segundo os testes bioquímicos e paraclínicos. Foram empregadas as técnicas de SSCP (Single Strand Conformation Polymorphism) e sequenciamento para analisar os éxons 3 a 12 do gene PAX8 e suas bordas éxon-intron. RESULTADOS: Nenhuma mutação foi encontrada nesses pacientes, em qualquer um dos éxons. CONCLUSÃO: Nossos resultados, mais uma vez, indicam que a taxa de mutação PAX8 é muito baixa e só pode explicar a minoria dos casos. Portanto, é altamente necessário investigar outros genes que controlam o desenvolvimento e as funções tireoideanas.

A novel mutation of the PAX6 gene in a Chinese family with aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>The 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.</p><p><b>METHODS</b>Two 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).</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Aniridia 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.</p>

Genotype/phenotype association in indian congenital aniridia.

The developmental birth eye disorder of iris is known as aniridia. Heterozygous PAX6 gene, which causes human aniridia and small eye in mice, is located on chromosome 11p13. The variability had been documented between the affected individuals within the families, is due to genotypic variation. Haploinsufficiency renders PAX6 allele non-functional or amorphic, however it presents hypomorphic or neomorphic alleles. India is not a well-studied ethnic group, hence the focus on congenital aniridia gene analysis supports the literature and the phenotypic association were analysed both in sporadic as well as familial. The consistent association of truncating PAX6 mutations with the phenotype is owing to non-sensemediated decay (NMD). It is presumed that the genetic impact of increased homozygosity and heterozygocity in Indian counter part arises as the consequence of consanguineous marriages. The real fact involved in congenital aniridia with other related phenotypes with PAX6 mutations are still controversial.

Mutation analysis of the PAX6 gene in a family with congenital aniridia and cataract / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutation in the PAX6 gene in a family with congenital aniridia and cataract.</p><p><b>METHODS</b>Total 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.</p><p><b>RESULTS</b>A 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.</p><p><b>CONCLUSION</b>The mutation (R261X) detected in the present study is considered to result in the occurrence of congenital aniridia and cataract in the Chinese family.</p>

R240X mutation of the PAX6 gene in a Chinese family with congenital aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the PAX6 gene mutation in a Chinese pedigree with congenital aniridia.</p><p><b>METHODS</b>Linkage 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Our results indicate that mutation p.Arg240Ter of the PAX6 is the genetic basis of the Chinese family with congenital aniridia.</p>

Expression of nNOS, Pax3 and Cx43 proteins in early developing posterior horn of embryonic and fetal human spinal cord / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the distribution pattern of the expressions neuronal nitric oxide synthase (nNOS), Pax3 and connexin 43 (Cx43) proteins in the early developing posterior horn of embryonic and fetal human spinal cord.</p><p><b>METHODS</b>Immunohistochemistry was used to detect the expressions of nNOS, Pax3 and Cx43 proteins in the posterior horn of the spinal cord during the second, third and fourth month of human embryonic and fetal development.</p><p><b>RESULTS</b>In the second to fourth month of gestation, the expressions of nNOS and Pax3 proteins increased gradually from weak expression to strong expression in the posterior horn of the spinal cord. In the second to third month of development, Cx43 protein expression was negative in the posterior horn of the spinal cord, but positive in the myelin sheath. In the fourth month, positive Cx43 expression was detected in some of the cells in the posterior horn of the spinal cord.</p><p><b>CONCLUSION</b>nNOS, Pax3 and Cx43 proteins are closely related to the growth and development of the spinal cord in human embryos and fetuses.</p>

Candidate gene polymorphisms for diabetes mellitus, cardiovascular disease and cancer are associated with longevity in Koreans

Long-lived people may have a unique genetic makeup that makes them more resistant than the general population to prevalent age-related diseases; however, not much is known about genes involved in the longevity. To identify susceptibility variants controlling longevity, we performed a high-throughput candidate gene study using 137 Koreans over 90 yr old and 213 young healthy Koreans. We evaluated 463 informative markers located in 176 candidate genes mostly for diabetes mellitus, cardiovascular disease and cancer under five genetic models. We estimated the odds ratios for each allele, genotype, haplotype, and gene-gene interaction using logistic regression analysis. Associations between 13 genes and longevity were detected at a P-value less than 0.01. Particularly, the rs671 (A) allele of the aldehyde dehydrogenase 2 family (mitochondrial) (ALDH2) gene was associated with longevity only in men (OR 2.11, P = 0.008). Four genes, proprotein convertase subtilisin/kexin type 1 (PCSK1, P = 0.008), epidermal growth factor receptor (EGFR, P = 0.003), paired box 4 (PAX4, P = 0.008), and V-yes-1 Yamaguchi sarcoma viral related oncogene homolog (LYN, P = 0.002) consistently yielded statistical evidence for association with longevity. The findings of the current study may provide a starting point for future studies to unravel genetic factors controlling longevity in Koreans.

Absence of mutations in Pax6 gene in three cases of Morning Glory syndrome associated with isolated growth hormone deficiency / A ausência de mutações no gene PAX6 em três casos de síndrome de Morning Glory associada à deficiência isolada de hormônio do crescimento

Morning glory syndrome (MGS) is a congenital optic disc dysplasia often associated with craniofacial anomalies, especially basal encephalocele and hypopituitarism. Clinical signs are varied and often occult. The PAX6 gene is involved in ocular morphogenesis and is expressed in numerous ocular tissues during development especially in the developing central nervous system. The aim of the present study is to evaluate PAX6 in MGS associated with isolated growth hormone deficiency. Three pre-pubertal males (A, B and C) with MGS and short stature due to growth hormone deficiency, treated with recombinant human growth hormone with limited response, were reported. Two of them had basal encephalocele. Coding and non-coding sequences corresponding of PAX6 different transcripts were analyzed by direct sequencing. Nucleotide variations causing putative aminoacid change were not observed. Patient A presented the new IVS2+9G>A transition, whereas patients A and C were heterozygous for known single nucleotide polymorphisms (SNP) within the intron 4. In addition, two SNP heterozygoses were observed for patient C in both intron 9 and 13. Sequencing also revealed several nucleotide variations in patient B. Two heterozygoses for known polymorphisms were identified along with a novel C>A nucleotide change in intron 4. This patient also presented a low number on the TG repeat in intron 9 and a new IVS11+33A>T transversion. Gene regulation and transcription of PAX6 are complex processes; there are two major protein isoforms, PAX6(-5a) and PAX6(+5a), and nine transcripts described. Furthermore, extra transcription regulatory elements have been postulated within PAX6 introns. Considering that neither population distributions on PAX6 polymorphism nor their linkeages with diseases have been reported, a functional effect due to alterations described here cannot be discarded.

A síndrome de Morning Glory (SMG) é uma displasia óptica congênita associada a anomalias craniofaciais, principalmente encefalocele basal e hipopituitarismo. Os sinais clínicos são variados e muitas vezes ocultos. O gene PAX6 está envolvido na morfogênese ocular e se expressa em vários tecidos oculares durante o desenvolvimento do sistema nervoso central. O objetivo deste estudo foi avaliar o gene PAX6 na SMG associada com deficiência isolada de hormônio de crescimento. Foram relatados três pacientes pré-púberes (A, B e C) com SMG e baixa estatura por deficiência de hormônio de crescimento tratados com hormônio de crescimento recombinante humano. As seqüências codificadoras e não-codificadoras correspondentes ao PAX6 em diferentes transcritos foram analisadas por seqüenciamento direto. Variações nucleotídeas com trocas pontuais de aminoácidos não foram encontradas. O paciente A apresentou uma transição nova IVS2+9G>A, enquanto os pacientes A e C foram heterozigotos para um polimorfismo (SNP) no íntron 4. Ainda, dois SNPs em heterozigose nos íntrons 9 e 13 foram observados no paciente C. O seqüenciamento também mostrou várias variações nucleotídeas no paciente B. Dois SNPs conhecidos com a alteração nucleotídea nova C>A no íntron 4 foram observados em heterozigose. Este paciente também apresentou um baixo número de repetições TG no íntron 9 e uma nova transversão IVS11+33A>T. A regulação e a transcrição do gene PAX6 são um processo complexo; existem 2 isoformas principais da proteína, PAX6(-5a) e PAX6(+5a) e 9 transcritos descritos. Considerando que nem a distribuição de SNPs no PAX6 e nem as suas ligações com as doenças foram relatadas, um defeito funcional devido às alterações descritas não pode ser descartado.

A novel mutation of the PAX6 gene identified in a northeastern Chinese family with congenital aniridia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutation of the PAX6 gene in a northeastern Chinese family with aniridia.</p><p><b>METHODS</b>Three aniridia patients from the family were undergone full ophthalmologic examinations. Genomic DNA was prepared from venous leukocytes from these three patients, five non-carriers in the family as well as 100 healthy normal controls. The coding regions of PAX6 gene were analyzed by PCR amplification, single-strand conformation polymorphism and direct DNA sequencing.</p><p><b>RESULTS</b>The sequencing result revealed one novel PAX6 mutation in the three patients with familial aniridia. The mutation is a 9 base pair(bp) deletion in exon 5 (c.483del9) that results in a putative PAX6 protein with in-frame deletions of aspartic acid, isoleucine and serine at the amino acids 41-43.</p><p><b>CONCLUSION</b>A PAX6 gene mutation beyond the existing spectrum of mutations has been identified in a northeastern Chinese family with aniridia. The genetic analysis suggests that the novel mutation in the PAX6 gene may be the cause of the classical aniridia phenotype.</p>

Occurrence of supernumerary upper incisor teeth in Pax6-/- mouse fetuses / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the occurrence of supernumerary upper incisor teeth in Pax6-/- mouse fetuses and to provide a model to explore the role of Pax6 in the upper incisor development and the mechanism of supernumerary teeth involving Pax6.</p><p><b>METHODS</b>Twenty Pax6-/- mouse fetuses of strain DEBA were isolated on E18.5 (embryonic day). The fetuses were sectioned serially in coronal plane and stained with haematoxylin and erosion, then the presence of supernumerary teeth in the upper anterior area was examined histologically, and also the number, morphology and structure of lower incisor germs and the first and second molar germs in the maxilla and mandible were observed histologically. Eighteen E18.5 mouse fetuses of strain DEBA with Pax6+/+ genotype were used as control.</p><p><b>RESULTS</b>Of the 20 Pax6-/- fetuses examined, four possessed a single supernumerary tooth in the upper incisors' region. No supernumerary upper incisor teeth were observed in any of the 18 Pax6+/+ fetuses examined. In the regions of lower incisors and the first and second molars of the maxilla and mandible, no significant difference was observed between Pax6-/- and Pax6+/+ fetuses regarding the number, morphology and structure of tooth germs.</p><p><b>CONCLUSIONS</b>The results suggest that Pax6 played an important role in the development of upper incisor teeth in mice.</p>