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.

Echocardiographic manifestation and analysis of TGFBR1 gene variant in a Chinese patient with Loeys-Dietz syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient with aortic root aneurysm and valve insufficiency.@*METHODS@#The patient was subjected to whole exome sequencing (WES) with a focus on the analysis of genes related to aortic aneurysm and other genetic diseases involving the cardiovascular system. Suspected pathogenic site was validated by Sanger sequencing of the patient and his family members.@*RESULTS@#WES has revealed a heterozygous c.830T>C variant (NM_001130916.3) in the patient, which was not detected among healthy members of his family. SIFT, PolyPhen2 and Mutation Taster predicted the variant to be disease causing, resulting in destruction of the structure and function of the TGFBR1 protein. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the variant was predicted to be likely pathogenic (PM1+PM2+PM6+PP3+PP4).@*CONCLUSION@#The c.830T>C variant of the TGFBR1 gene probably underlay the disease in the proband. Above finding has enriched the spectrum of TGFBR1 gene variants in Chinese population.