Clinical and genetic analysis of a patient with Loeys-Dietz syndrome due to variant of TGFBR2 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a patient with clinically suspected Loeys-Dietz syndrome (LDS).@*METHODS@#A child who had presented at Beijing Anzhen Hospital in September 2018 was selected as the study subject. Clinical data and family history of the patient were collected, along with peripheral blood samples of the proband and his parents. Whole exome sequencing (WES) was carried out through next-generation sequencing.@*RESULTS@#Candidate variants were searched through bioinformatic analysis focusing on genes associated with hereditary aortic aneurysms. Candidate variant was verified by Sanger sequencing. The patient was found to have cardiovascular abnormalities including early-onset aortic dilatation and coarctation, and LDS syndrome was suspected. WES revealed that he has harbored a heterozygous c.1526G>T missense variant of the TGFBR2 gene. The same variant was not found in either parent and was predicted as likely pathogenic (PM1+PM2_Supporting+ PM6+PP3+PP4) based on the guidelines from the American College for Medical Genetics and Genomics (ACMG).@*CONCLUSION@#The TGFBR2 c.1526G>T variant probably underlay the LDS in this patient and was unreported previously in China. Above finding has enriched the mutational spectrum of the TGFBR2 gene associated with the LDS and provided a basis for the genetic counseling for the patient.

Clinical and genetic characteristics of 12 cases of Loeys-Dietz syndrome / 中华医学遗传学杂志

OBJECTIVE@#To summarize the clinical features and spectrum of genetic variants in 12 patients with Loeys-Dietz syndrome (LDS), and to explore the correlation between the type of genetic variants and clinical phenotypes.@*METHODS@#Twelve patients suspected for LDS at Beijing Anzhen Hospital Affiliated to Capital Medical University from January 2015 to January 2022 were selected as the study subjects. Clinical data of the patients were collected. Genomic DNA was extracted from peripheral blood samples and subjected to genetic testing. Pathogenicity of candidate variants was analyzed.@*RESULTS@#The clinical phenotypes of the 12 patients have mainly included cardiovascular, musculoskeletal, craniofacial, skin, ocular and other systemic signs. Four patients (patients 5-1, 5-2, 6, 7) have carried heterozygous missense variants of the TGFBR1 gene, 5 patients (patients 1-1, 1-2, 2, 3, 4) have carried heterozygous variants of the TGFBR2 gene, and 2 patients (patients 8-1, 8-2) had carried heterozygous frameshift variants of the TGFB3 gene. One patient (patient 9) had carried a heterozygous missense variant of the SMAD3 gene. Among these, TGFBR1 c.603T>G (p.1201M) and TGFB3 c.536delA (p.H179FS35) had not been reported previously.@*CONCLUSION@#Variants of the TGFBR1, TGFBR2, SMAD3, TGFB2, TGFB3 and SMAD2 genes are mainly associated with LDS. The severity of the disease phenotype caused by the same variant may vary, whilst the clinical phenotype caused by different variant sites may be specific.

Clinical utility of TGFB1 and its receptors (TGFBR1 and TGFBR2) in thyroid nodules: evaluation based on single nucleotide polymorphisms and mRNA analysis

ABSTRACT Objective: Abnormalities involving the TGFB1 gene and its receptors are common in several types of cancer and often related to tumor progression. We investigated the role of single nucleotide polymorphisms (SNP) in the susceptibility to cancer, their impact on its features, as well as the role of mRNA expression of these genes in thyroid malignancy. Materials and methods: We genotyped TGFB1, TGFBR1, and TGFBR2 SNPs in 157 papillary thyroid cancer (PTC) patients and 200 healthy controls. Further, we investigated RNA samples of 47 PTC and 80 benign nodules, searching for differential mRNA expression. Results: SNPs rs1800472 and rs1800469 were associated with characteristics of PTC aggressiveness. Effect predictor software analysis of nonsynonymous SNP rs1800472 indicated increasing protein stability and post-translational changes. TGFB1 mRNA expression was upregulated in PTC and downregulated in benign samples, differentiating malignant from benign nodules (p<0.0001); PTC from goiter (p<0.0001); and PTC from FA (p<0.0001). TGFBR1 mRNA expression was upregulated in goiter and PTC, but downregulated in FA, distinguishing PTC from goiter (p=0.0049); PTC from FA (p<0.0001); and goiter from FA (p=0.0267). On the other hand, TGFBR2 was downregulated in all histological types analyzed and was not able to differentiate thyroid nodules. Conclusion: TGFB1 polymorphism rs1800472 may confer greater activity to TGF-β1 in the tumor microenvironment, favoring PTC aggressiveness. Evaluation of TGFB1 and TGFBR1 mRNA levels may be useful to identify malignancy in thyroid nodules.