[Hereditary pulmonary hypertension family with BMPR2 gene variation: a case report and literature review].

Objective: To describe the clinical characteristics, diagnosis, genetic features and treatment of hereditary pulmonary hypertension complicated with suspected hereditary hemorrhagic telangiectasia (HHT). Methods: Firstly, we summarized and analyzed the clinical data of two cases of suspected HHT admitted to the Department of Pulmonary and Critical Care Medicine, the Second Xiangya Hospital, Central South University. Secondly, the genes of peripheral blood of patients and their families were completely sequenced and sanger sequencing was performed to verify the variation sites, and then the mRNA deletion caused by the variation was further verified. Thirdly, "HHT" "FPAH" and "BMPR2 gene variation" were used as keywords,and the related literatures of Wanfang database and PubMed database from January 2000 to November 2021 were searched and reviewed. Results: We found two patients in a family from Yiyang, Hunan province, who had symptoms of hemoptysis or pulmonary hypertension without epistaxis or other clinical features of HHT. However, both patients had pulmonary vascular abnormalities and pulmonary hypertension in their lungs. We found that BMPR2 gene variation (NM_001204.7:c.1128+1G>T) was positive and ENG, ACVRL1 and SMAD4 genes were negative. Family analysis and Sanger verification were carried out on 16 individuals in 4 generations of the family (7 of whom were found to carry the mutant gene), and then transcriptional level mRNA sequencing further confirmed that the variation resulted in the deletion of exon 8 and exon 9, and amino acid sequence estimation revealed that the amino acids of the protein from 323 to 425 were deleted. We thought that the incomplete translation of BMPR2 gene could lead to BMPRⅡ dysfunction. Therefore, it was diagnosed as hereditary pulmonary hypertension with suspected HHT. Both patients were suggested to reduce the pulmonary artery pressure, and at the same time, the whole-body imaging examination should be performed to screen other arteriovenous malformations, and the annual cardiac color Doppler ultrasound should be reviewed to evaluate the changes of pulmonary artery pressure. Conclusions: Hereditary pulmonary hypertension (HPAH) is a group of diseases with increasing pulmonary vascular resistance caused by genetic factors, including familial PAH and simple PAH. Variation in the BMPR2 gene is an important pathogenic factor of HPAH. Therefore, we should pay attention to the inquiry of family history when we clinically encounter young patients with pulmonary hypertension. If the cause is unknown, genetic testing is recommended. HHT is a rare autosomal dominant genetic disease. The possibility of this disease should be considered in clinical manifestations such as familial pulmonary vascular abnormality, pulmonary hypertension and recurrent epistaxis. There is no effective specific treatment for HPAH and HHT, which are treated symptomatically (including blood pressure reduction and hemostasis, etc.). It is suggested for these patients that pulmonary artery pressure should be dynamically monitored and have genetic counseling before giving birth.目的： 探讨遗传性肺动脉高压合并疑似遗传性出血性毛细血管扩张症（HHT）患者的临床特征、诊断要点、遗传学特点及治疗方法。 方法： 分析中南大学湘雅二医院呼吸与危重症学科收治的遗传性肺动脉高压家系合并疑似遗传性出血性毛细血管扩张症的患者临床资料。对患者及患者家系外周血基因进行全外显子基因测序并进行sanger测序验证突变位点，后进一步验证该突变所导致的mRNA缺失情况。以“HHT”“FPAH”“骨形态发生蛋白受体2（BMPR2）基因突变”为关键词，检索自2000年1月至2021年11月的万方数据库和PubMed数据库相关文献并进行复习。 结果： 我们发现来自湖南益阳的一个家系中的2例患者，以咯血或肺动脉高压症状为主要临床表现，无鼻出血等HHT临床特征，然而2例患者肺部均出现肺血管异常、肺动脉高压，WES发现BMPR2基因突变（NM_001204.7：c.1128+1G>T）阳性而ENG、ACVRL1、SMAD4基因阴性，对家族4代16人进行调查家系分析和sanger验证（发现其中7人携带该突变基因），然后转录水平mRNA测序进一步证实该突变导致8号9号外显子缺失，进行氨基酸序列推测发现该蛋白从323到425位的氨基酸出现了缺失。我们认为BMPR2基因翻译不完整可能导致BMPR2功能障碍。因此，诊断为遗传性肺动脉高压合并疑似遗传性出血性毛细血管扩张症。两位患者均建议予以降低肺动脉压力治疗，同时行全身影像学检查筛查其他动静脉畸形，并年度复查心脏彩超，评估肺动脉压力变化。 结论： 遗传性肺动脉高压（HPAH）是一组由遗传因素引起肺血管阻力持续增加的疾病，包括家族性PAH和单纯性PAH。BMPR2基因突变是HPAH的重要致病因素。临床上遇见年轻肺动脉高压患者，应注意家族史的询问。当病因不明时，建议进行基因检测。HHT是一种少见的常染色体显性遗传病。临床上遇到家族性肺部血管异常，肺动脉高压且合并反复鼻出血等临床表现应想到本病的可能性。HPAH和HHT均无有效的特殊治疗，均为对症治疗（包括降压、止血等）。建议该类患者动态检测肺动脉压力，生育前遗传咨询。.