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.

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.

Síndrome de Loeys-Dietz, 3 generaciones, 4 casos familiares / Loeys-Dietz Syndrome, 3 generations, 4 familial cases

El síndrome de Loeys-Dietz es una enfermedad genética autosómica dominante caracterizada por aneurismas aórticos, tortuosidad arterial generalizada, hipertelorismo y úvula bifida o paladar hendido. La complicación cardiovascular más grave es la disección aórtica. Se presentan cuatro casos familiares de este síndrome en tres generaciones, todos con dilatación aórtica grave, y se describen sus aspectos diagnósticos, indicación y tratamiento quirúrgico, como así también pautas de seguimiento.

Loeys-Dietz Syndrome is an autosomal dominant disease with aortic aneurysms, arterial tortuosity with hypertelorism and bifid uvula. We describe four familial cases within three generations. The diagnosis, surgical management and followup will be addressed.