[Association of single nucleotide polymorphisms of TBX5 gene and environmental exposure index with susceptibility to oral cancer].

Objective: To explore the association of TBX5 polymorphisms and environmental exposure index with susceptibility to oral cancer. Methods: A case-control study was conducted to collect 300 oral cancer patients hospitalized in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Fujian Medical University from September 2010 to December 2016. A total of 445 non-tumor patients were selected as the control group. Questionnaires were used to collect the information of all subjects and 5 ml peripheral blood was collected to detect single nucleotide polymorphisms (SNPs) of the rs10492336 locus of TBX5 gene. According to the environmental exposure index score, subjects were divided into two groups, low risk group (0-2.31) and high risk group (2.32-11.76). To analyze the association of TBX5 gene rs10492336 SNPs, environmental exposure index and oral cancer and its interactions. Results: The age of all subjects in the case group and control group were (56.19±13.10) years and (54.56±12.48) years old. Compared with CC genotype, the OR (95%CI) values of the co-dominant genetic model AC genotype and the dominant genetic model AC+AA genotype were 0.69 (0.49-0.98) and 0.70 (0.51-0.97), respectively. Compared with the low risk group, the OR (95%CI) risk of oral cancer in the high risk group was 3.72 (2.55-5.43). The results of gene-environment interaction analysis showed that compared with the group with CC genotype and high risk of environmental exposure index, the OR (95%CI) value of oral cancer in the group with AC+AA genotype and low risk of environmental exposure index was 0.18(0.10-0.31). Furthermore there was a multiplicative interaction between rs10492336 SNPs and environmental exposure index (ß=-0.405, P<0.001). Conclusion: This study suggests that the TBX5 gene rs10492336 SNPs and environmental exposure index were associated with oral cancer. And there was a multiplication interaction between rs10492336 SNPs and environmental exposure index.

Clinical expression of Holt-Oram syndrome on the basis of own clinical experience considering prenatal diagnosis.

OBJECTIVES: Holt-Oram syndrome manifests with defects of upper limbs, pectoral girdle and cardiovascular system. The aim of this paper was to present complex clinical picture of the syndrome and its variable expression on the example of the family diagnosed genetically on the neonatal ward, after proband's prenatal examination. MARETIAL AND METHODS: Nine family members were tested for TBX5 gene mutation. RESULTS: Four of family members were diagnosed with Holt-Oram syndrome and five had correct genetic test results. The diagnosis allowed to identify a genetic risk family and enabled to provide them with genetic counselling. CONCLUSIONS: Diagnosis of Holt-Oram syndrome is possible as early as in prenatal period and it can be verified by genetic tests.

DNA Methylation Levels of the TBX5 Gene Promoter Are Associated with Congenital Septal Defects in Mexican Paediatric Patients.

The TBX5 gene regulates morphological changes during heart development, and it has been associated with epigenetic abnormalities observed in congenital heart defects (CHD). The aim of this research was to evaluate the association between DNA methylation levels of the TBX5 gene promoter and congenital septal defects. DNA methylation levels of six CpG sites in the TBX5 gene promoter were evaluated using pyrosequencing analysis in 35 patients with congenital septal defects and 48 controls. Average methylation levels were higher in individuals with congenital septal defects than in the controls (p < 0.004). In five CpG sites, we also found higher methylation levels in patients than in the controls (p < 0.05). High methylation levels were associated with congenital septal defects (OR = 3.91; 95% CI = 1.02-14.8; p = 0.045). The analysis of Receiver Operating Characteristic (ROC) showed that the methylation levels of the TBX5 gene could be used as a risk marker for congenital septal defects (AUC = 0.68, 95% CI = 0.56-0.80; p = 0.004). Finally, an analysis of environmental factors indicated that maternal infections increased the risk (OR = 2.90; 95% CI = 1.01-8.33; p = 0.048) of congenital septal defects. Our data suggest that a high DNA methylation of the TBX5 gene could be associated with congenital septal defects.

Holt-Oram Syndrome: An Incidental Diagnosis.

Holt-Oram syndrome is a rare autosomal dominant disorder which occurs because of mutations in the TBX5 genes. Most notable manifestations include musculoskeletal deformities, predominantly affecting the upper limbs, and congenital heart defects. Presentation could be multifaceted leading to delay in diagnosis. We describe an interesting incidental diagnosis of Holt-Oram syndrome in a young female adult who accompanied her son to the clinic. He had undergone closure of both atrial septal defect (ASD) and patent ductus arteriosus (PDA) in his infancy. She reported progressive exertional dyspnoea, reduced exercise tolerance, and palpitations; incidentally, she was noted to have right upper limb deformities. These findings prompted further evaluation and thereafter, resulted in a diagnosis of Holt-Oram syndrome.

Prenatal Diagnosis of Holt-Oram Syndrome With a Novel Mutation of TBX5 Gene: A Case Report.

Background: Holt-Oram syndrome (HOS) is an autosomal dominant disorder caused by mutations of TBX5 gene. Case presentation: We report a fetus with HOS diagnosed sonographically at 23 weeks of gestation. The fetal parents are non-consanguineous. The fetus exhibited short radius and ulna, inability to supinate the hands, absence of the right thumb, and heart ventricular septal defect (VSD), while the fetal father exhibited VSD and short radius and ulna only. Fetal brother had cubitus valgus and thumb adduction, except for VSD, short radius and ulna. The pregnancy was terminated. Whole-exome sequencing (WES) revealed a novel mutation in the TBX5 (c.510+1G>A) in the fetus inherited from the father. The variant (c.510+1G>A) occurs at splice donor and may alter TBX5 gene function by impact on splicing. It was not previously reported in China. Conclusion: Our case reported a novel mutation in TBX5, which expanded the known genetic variants associated with HOS.

Holt-Oram Syndrome: Hands are the Clue to the Diagnosis.

Holt-Oram syndrome or heart-hand syndrome consists of phenotypic and genotypic abnormalities. It is characterized by abnormalities of upper limbs and congenital cardiac defects. It is an autosomal dominant disorder due to a mutation in TBX5 gene located on chromosome 12, but sporadic cases have also been reported. We describe a 26-year-old female with a history of shortness of breath for 5 years. She had bilateral hand deformities, and on evaluation, found to have ostium secundum atrial septal defect which is common cardiac defect in Holt-Oram syndrome.

A novel mutated sequence in the T-box transcription factor-5 (TBX-5) gene (c.241A>T) in Holt-Oram syndrome.

We report a case of a 31-year-old pregnant woman who was admitted to our perinatology outpatient clinic because of a fetal ventricular septal defect and limb reduction in the upper extremities of fetus revealed by ultrasonographic investigation diagnosed in the 16(th) week of gestation. First child of the family was diagnosed with Holt-Oram syndrome who had atrial septal defect and upper limb anomalies, whereas the father was documented to have arrhythmia and shortening of upper limbs. The pregnancy was terminated in the 16(th) week of gestation with the consent of the family. We performed mutation analysis in T-box transcription factor-5 (TBX5) gene coding exons, including exon/intron boundaries from peripheral blood or skin fibroblasts. The sequence analysis revealed c.241 adenine (A)>thymine (T) [p. arginine (Arg) 81 Tryptophan (Trp)] alteration in exon-3 of the TBX5 gene in affected family members and fetus. This is a novel mutation causing Holt-Oram syndrome.

Effects of obesity on the association between common variations in the TBX5 gene and matrix metalloproteinase 9 levels in Taiwanese.

OBJECTIVES: The TBX5 gene, a member of the T-box family, is associated with congenital heart disease, electrocardiographic parameters, and development of atrial fibrillation in the general population. This study aimed to elucidate the role of TBX5 gene polymorphisms in metabolic and inflammatory profiles possibly linked to TBX5-related pathologies. MATERIALS AND METHODS: A sample population of 597 individuals having routine health examinations was enrolled. Five tagging TBX5 single nucleotide polymorphisms (SNPs) were analyzed using polymerase chain reaction and restriction enzyme digestion or TaqMan SNP genotyping assays. Associations between genotypes/haplotypes and matrix metalloproteinase 9 (MMP9) levels were investigated using generalized linear model analysis. Interactions between each genotype/haplotype, MMP9 level, and obesity status were tested using two-way analysis of variance with Golden Helix SVS Win32 7.3.1 software. RESULTS: After adjusting for clinical covariates, TBX5 genotypes were found to be associated with MMP9 levels (p = 0.002 and p = 0.001 for rs4113925 and rs3825214, respectively) in a dominant inheritance model. Haplotype analysis using three tag SNPs (rs11067101, rs1247973, and rs3825214) revealed a significant association between TBX5 haplotype GCG and MMP9 levels (uncorrected p = 0.0093 and the corrected false discovery rate p = 0.0435). Multivariate analysis identified that SNP rs3825214, in addition to the MMP9 and E-selectin genotypes, was independently associated with MMP9 levels (p < 0.001). Using a dominant inheritance model, subgroup and interaction analysis showed associations between the rs4113925, rs3825214, and MMP9 levels only in nonobese individuals (p = 1.04 × 10-4 and p = 7.11 × 10-5, respectively; interaction p = 0.009 and 0.018, respectively). Subgroup analysis showed a borderline significant association between haplotype GCG and MMP9 levels (uncorrected p = 0.020 and corrected false discovery rate p = 0.073), but with no evidence of interaction. CONCLUSION: TBX5 genotypes/haplotypes are independently associated with MMP9 in Taiwanese individuals and occur predominantly in nonobese people. These associations may broaden our understanding of the mechanism underlying T-box family gene activity and related cardiovascular pathologies.

Life-threatening cardiac episode in a Polish patient carrying contiguous gene microdeletion of the TBX5 and the TBX3 genes.

Holt-Oram syndrome (HOS) features radial ray hypoplasia, heart defect and cardiac conduction impairment. Ulnar-mammary syndrome (UMS) characterizes congenital defects of the ulnar side of the upper limbs, underdevelopment of apocrine glands including hypoplasia and the dysfunction of mammary glands, hypogonadism and obesity. Inheritance of both conditions is autosomal dominant, mutations or deletions are found in the TBX5 and TBX3 gene, respectively. The Polish patient presented short stature, obesity, congenital malformation of the radial and ulnar side of the upper limbs, heart block, hypogonadism and dysmorphic features. At the age of 13 years he lost consciousness developing respiratory insufficiency caused by bradycardia in the course of sudden atrioventricular third degree heart block requiring immediate implantation of pace maker-defibrillator device. Microdeletion of the 12q24.21 was identified using array CGH method. This region includes contiguous genes the TBX5, TBX3, and part of RBM19. The patient initially diagnosed as having HOS, was found to present the UMS features as well. Array CGH method should be applied in patients suspected of HOS or UMS, especially when sequencing of TBX5 or TBX3 genes fails to identify causative mutation.

A genetic assay of three patients in the same family with Holt-Oram syndrome; a case report.

Holt-Oram syndrome (HOS) is a developmental disorder inherited in an autosomal-dominant pattern. Affected organs are the heart and forelimbs with upper extremity skeletal defects and congenital heart malformation. In this study we present three cases of HOS in the same family. In one of these three individuals we detected a transition of C to T (CTG-GTT, V205V) in exon 7 of the TBX5 gene. This nucleotide change causes no amino acid change and potential pathologic effects remain unknown.

Novel mutations in the TBX5 gene in patients with Holt-Oram Syndrome.

The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father.

Novel mutations in the TBX5 gene in patients with Holt-Oram Syndrome

The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father.