Clinical manifestations and genetic analysis of 4 patients with variants of FBN1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for four patients suspected for Marfan syndrome (MFS).@*METHODS@#Four male patients with suspected MFS and their family members who were treated at West China Second Hospital of Sichuan University from September 12, 2019 to March 27, 2021 were selected as the study subjects. Peripheral venous blood samples were collected from the patients and their parents or other pedigree members for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were validated by Sanger sequencing. The pathogenicity of the variants was determined based on the guidelines from the American College of Medical Genetics and Genomics (ACMG).@*RESULTS@#Genetic testing revealed that all four patients have harbored variants of the FBN1 gene, including c.430_433del (p.His144fs) deletional variant in exon 5, c.493C>T (p.Arg165*) nonsense variant in exon 6, c.5304_5306del (p.Asp1768del) deletional variant in exon 44 and c.5165C>G (p.Ser1722Cys) missense variant in exon 42. According to the ACMG guidelines, the c.430_433del and c.493C>T were classified as pathogenic variants (PVS1+PM2_Supporting+PP4; PVS1+PS1+PS2+PM2_Supporting+PP4). c.5304_5306del and c.5165C>G were classified as likely pathogenic variants (PS2+PM2_Supporting+PM4+PP4; PS2_Moderate+PS1+PM1+PM2_Supporting).@*CONCLUSION@#The c.430_433del and c.5304_5306del variants of the FBN1 gene identified in this study were unreported previously. Above results have enriched the variation spectrum of the FBN1 gene and provided a basis for genetic counseling and prenatal diagnosis of patients with MFS and acromicric dysplasia.

Analysis of a child with Marfan syndrome due to a novel variant of FBN1 gene / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic testing for a child with Marfan syndrome (MFS) and explore its genotype-phenotype correlation.@*METHODS@#Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA and subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Functional impact of the variant was predicted by using bioinformatic software.@*RESULTS@#The child, a 13-year-old male, has featured Marfanoid habitus, with arm span exceeding his height, tapering fingers and toes, pectus excavatum and scoliosis, but absence of typical cardiovascular system diseases such as aortic dilation, thoracic-abdominal aortic aneurysm, mitral valve prolapse, and lens dislocation. The child has harbored a novel splice site variant c.7383_7413del (p. N2461Kfs*211) of the FBN1 gene, which was not found in his parents and younger brother. The variant was unreported previously.@*CONCLUSION@#The novel variant of p. N2461Kfs*211 of the FBN1 gene probably underlay the MFS in this child. Above finding has enriched the genotypic and phenotypic spectrum of MFS.

Latest advances in the diagnosis and treatment of Marfan syndrome / 中国当代儿科杂志

Marfan syndrome (MFS) is a multisystem connective tissue disease with autosomal dominant inheritance. It is mainly caused by FBN1 gene mutation and often has different clinical manifestations. Neonatal MFS is especially rare with severe conditions and a poor prognosis. At present, there is still no radical treatment method for MFS, but early identification, early diagnosis, and early treatment can effectively prolong the life span of patients. This article reviews the latest advances in the diagnosis and treatment of MFS.

A de novo mutation leading to Marfan syndrome in a case / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child featuring unexplained rapid growth and heart malformation.@*METHODS@#Whole exome sequencing (WES)was carried out for the patient. Suspected variant was verified by Sanger sequencing and subjected to bioinformatic analysis.@*RESULTS@#The child was found to harbor a novel de novo c.5846_5848delATA (p. N1949del) variant in exon 48 of the FBN1 gene, which was predicted to be pathogenic by Mutation Taster. The patient was ultimately diagnosed with Marfan syndrome.@*CONCLUSION@#Above finding has enriched the spectrum of genetic variants associated with Marfan syndrome. WES has provided a powerful tool for the diagnosis of rare diseases.

A c.3037G>A mutation in FBN1 gene causing Marfan syndrome with an atypically severe phenotype / Mutación c.3037G>A en el gen FBN1 causa sindrome de Marfan con fenotipo atípico severo

Marfan syndrome is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, mostly caused by mutations in the FBN1 gene, which is located on chromosome 15q21.1 and encoding fibrillin 1. We report a case of Marfan syndrome presen ting with severe ocular and systemic manifestations, such as cardiac congenital anomalies. The patient underwent a multidisciplinary approach and his clinical diagnosis was associated with a c.3037G>A mutation in the FBN1 gene. Identification of this genetic alteration should instigate a prompt multidisciplinary assessment and monitoring, in order to prevent devasta ting consequences such as cardiac and ocular phenotype. Molecular modeling of the mutation highlighted the importance of the preservation of the calcium-dependent structure of an epidermal-growth-factor-like domain of fibrillin-1 and consequently the microfibrillar formation process. This report aims to highlight the importance of an early clinical and molecular diagnosis and once more, the importance of the multidisciplinary approach of this genetic entity.

El síndrome de Marfan es una enfermedad pleitrópica del tejido conjuntivo que exhibe un patrón de herencia autosómico dominante, en su mayoría causado por mutacio nes en el gen FBN1 , que se encuentra en el cromosoma 15q21.1 y codifica a la fibrilina 1. Se presenta un caso de síndrome de Marfan que cursa con manifestación sistémica severa cardíaca y principlamente ocular. El paciente presentó una valoración multidisciplinaria y su diagnóstico clínico fue asociado con la mutación c.3037G>A en el gen FBN1 . La identificación de esta alteración genética debe promover una pronta evaluación y supervisión con el fin de evitar las desvastadoras consecuencias, tales como el fenotipo cardíaco y ocular. El modelado comparativo de proteínas resalta la importancia de la conservación de la estructura del dominio de la fibrilina-1 dependiente de calcio similar al factor de crecimiento epidérmico y por lo tanto el proceso de formación microfibrilar. Este informe tiene como objetivo resaltar la importancia de un diagnóstico clínico y molecular temprano y el enfoque multidisciplinariode esta entidad genética.

Acromicric Dysplasia Caused by a Novel Heterozygous Mutation of FBN1 and Effects of Growth Hormone Treatment

No abstract available.