马艳云
中国医学科学院阜外医院 实验诊断中心
BACKGROUND:Variants in the gene encoding bone morphogenetic protein receptor type II (BMPR2) are the most common genetic cause of pulmonary arterial hypertension (PAH), whereas biallelic variants in the eukaryotic translation initiation factor 2 alpha kinase 4 gene (EIF2AK4) are described in pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis (PVOD/PCH). Racial background may influence the clinical characteristics of patients diagnosed with PAH or PVOD/PCH. Here, we compared the clinical characteristics and survival between patients with BMPR2 variants or EIF2AK4 variants in a Chinese population.METHODS:Heterozygous variants in BMPR2 and homozygous or compound heterozygous biallelic EIF2AK4 variants predicted to be deleterious were identified as potentially causal. Clinical and radiological data were collected and analysed. The primary outcomes were death or lung transplantation. Hazard ratios (HRs) for death or transplantation associated with the presence of BMPR2 or biallelic EIF2AK4 variants were calculated using Cox proportional hazards models to analyse patient survival.RESULTS:Two hundred thirty-two patients with PAH were enrolled for genetic testing, and PAH patients with associated conditions were excluded from the study. Forty-five patients with BMPR2 variants and 11 patients with biallelic EIF2AK4 variants were recruited. PAH patients with BMPR2 or biallelic EIF2AK4 variants presented symptoms at the ages of 25.57 ± 10.17 years and 31.6 ± 9.38 years, respectively. The whole group of patients showed female dominance either with BMPR2 variants or biallelic EIF2AK4 variants. Specific radiological abnormalities are more prominent in EIF2AK4 variant carriers but can also be found in some patients with BMPR2 variants. Biallelic EIF2AK4 variant carriers had worse survival than BMPR2 variant carriers (p < 0.0001).CONCLUSIONS:Clinical pictures of PAH patients with BMPR2 and biallelic EIF2AK4 variants in the Chinese population differ from other populations by a younger age at diagnosis and demonstrate female dominance in the whole patient group. High-resolution chest CT can help assist in differentiating PAH with PVOD/PCH. BMPR2 variants and biallelic EIF2AK4 variants are associated with adverse outcomes, but the survival of patients with biallelic EIF2AK4 variants is dismal.
BMC pulmonary medicine 2020
BACKGROUND:Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder for which 6 genes in the TGF-β pathway have been identified as causative. With the widespread use of genetic testing, the range of known clinical and genetic profiles has broadened, but these features have not been fully elucidated thus far.METHODS AND RESULTS:Using gene panel sequencing or whole exome sequencing, we identified 54 unique rare variants in LDS genes in 57 patients with thoracic aneurysms/dissections, including 27 pathogenic mutations (P + LP) and 27 variants of unknown significance (VUSLP + VUS). Genotype-phenotype correlation analysis revealed that carriers with P/LP/ VUSLP variants in TGFBR1/TGFBR2/SMAD3 genes had significantly more severe cardiovascular features (cardiovascular death/dissection) than carriers with VUSs in these 3 genes at an early age and had less favorable event-free survival. Additionally, carriers with VUS in combination with other risk factors, such as hypertension, might be prone to developing an aortic dissection, as indicated by the fact that 5/8 (62.5%) patients with VUSs in our cohort developed aortic dissections in the presence of hypertension, compared with 25.0% (3/12) in the absence of hypertension (p = 0.047).CONCLUSIONS:To date, this was the largest cohort of LDS patients ever reported in China, and the present study expanded the known mutation and phenotypic spectra of LDS, which might help refine our knowledge of LDS.
Orphanet journal of rare diseases 2020
BACKGROUND:Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutations in the FBN1 gene. Approximately 90% of classic MFS patients have a FBN1 mutation that can be identified by single-gene sequencing or gene-panel sequencing targeting FBN1. However, a small proportion of MFS patients carry a large genomic deletion in FBN1, which cannot be detected by routine sequencing. Here, we performed an MLPA (multiplex ligation-dependent probe amplification) test to detect large deletions and/or duplications in FBN1 and TGFBR2 in 115 unrelated Chinese patients with suspected MFS or early-onset aneurysm/dissection.RESULTS:Five novel large deletions encompassing a single exon or multiple exons in the FBN1 gene were characterized in five unrelated patients, of which four were proven by Sanger sequencing, and the breakpoints were identified. Three of them met the revised Ghent criteria when genetic results were not available, and the other two patients were highly suspected and diagnosed with MFS until the FBN1 deletions were identified.CONCLUSIONS:Our finding expands the mutation spectrum of large FBN1 deletions and emphasizes the importance of screening for large FBN1 deletions in clinical genetic testing, especially for those with classic Marfan phenotype.
Human genomics 2018
BACKGROUND:Pulmonary arterial hypertension (PAH) is a progressive and fatal disorder associated with high pulmonary artery pressure. Genetic testing enables early diagnosis and offers an opportunity for family screening. To identify genetic mutations and help make a precise diagnosis, we performed genetic testing in 191 probands with PAH and tried to analyze the genotype-phenotype correlation.METHODS:Initially, PAH samples (n = 119) were submitted to BMPR2 screening using Sanger sequencing. Later, we developed a PAH panel test to identify causal mutations in 13 genes related to PAH and tried to call BMPR2 copy number variations (CNVs) with the panel data. Multiplex ligation-dependent probe amplification (MLPA) was used to search for CNVs in BMPR2, ACVRL1 and ENG. Notably, EIF2AK4 gene was also involved in the panel, which allowed to distinguish pulmonary veno-occlusive disease (PVOD)/pulmonary capillary hemangiomatosis (PCH) patients from idiopathic PAH (IPAH). Characteristics of patients were compared using t test for continuous variables.RESULTS:Pathogenic BMPR2 mutations were detected most frequently in 32 (17.9%) IPAH and 5 (41.7%) heritable PAH (HPAH) patients by sequencing, and 12 BMPR2 CNVs called from the panel data were all successfully confirmed by MLPA analysis. In addition, homozygous or compound heterozygous EIF2AK4 mutations were identified in 6 patients, who should be corrected to a diagnosis of PVOD/PCH. Genotype-phenotype correlation analysis revealed that PAH patients with BMPR2 mutations were younger at diagnosis (27.2y vs. 31.6y, p = 0.0003) and exhibited more severe pulmonary hemodynamic impairment and a worse cardiac index compared with those without BMPR2 mutations.CONCLUSIONS:The panel assay represented a highly valuable tool in PAH genetic testing, not only for the detection of small sequence alterations, but also for an indication of BMPR2 CNVs, which had implications for the specific samples to perform further MLPA assay. Analyses of PAH causal genes have a great help to clinical diagnosis and deep implications in disease treatment.
Respiratory research 2018
Inherited aortopathy, which is characterized by a high risk of fatal aortic aneurysms/dissections, can occur secondarily to several syndromes. To identify genetic mutations and help make a precise diagnosis, we designed a gene panel containing 15 genes responsible for inherited aortopathy and tested 248 probands with aortic disease or Marfan syndrome. The results showed that 92 individuals (37.1%) tested positive for a (likely) pathogenic mutation, most of which were FBN1 mutations. We found that patients with a FBN1 truncating or splicing mutation were more prone to developing severe aortic disease or valvular disease. To date, this is the largest reported cohort of Chinese patients with aortic disease who have undergone genetic testing. Therefore, it can serve as a considerable dataset of next generation sequencing data analysis of Chinese population with inherited aortopathy. Additionally, according to the accumulated data, we optimized the analysis pipeline by adding quality control steps and lowering the false positive rate.
Scientific reports 2016
