Aortic disease and cardiomyopathy in patients with a novel DNMT3A gene variant causing Tatton-Brown-Rahman syndrome.

Tatton-Brown-Rahman syndrome (TBRS) is a rare congenital genetic disorder caused by autosomal dominant pathogenic variants in the DNA methyltransferase DNMT3A gene. Typical TBRS clinical features are overgrowth, intellectual disability, and minor facial anomalies. However, since the syndrome was first described in 2014, a widening spectrum of abnormalities is being described. Cardiovascular abnormalities are less commonly reported but can be a major complication of the syndrome. This article describes a family of three individuals diagnosed with TBRS in adulthood and highlights the variable expression of cardiovascular features. A 34-year-old proband presented with progressive aortic dilatation, mitral valve (MV) regurgitation, left ventricular (LV) dilatation, and ventricular arrhythmias. The affected family members (mother and brother) were diagnosed with MV regurgitation, LV dilatation, and arrhythmias. Exome sequencing and computational protein analysis suggested that the novel familial DNMT3A mutation Ser775Tyr is located in the methyltransferase domain, however, distant from the active site or DNA-binding loops. Nevertheless, this bulky substitution may have a significant effect on DNMT3A protein structure, dynamics, and function. Analysis of peripheral blood cfDNA and transcriptome showed shortened mononucleosome fragments and altered gene expression in a number of genes related to cardiovascular health and of yet undescribed function, including several lncRNAs. This highlights the importance of epigenetic regulation by DNMT3A on cardiovascular system development and function. From the clinical perspective, we suggest that new patients diagnosed with congenital DNMT3A variants and TBRS require close examination and follow-up for aortic dilatation and valvular disease because these conditions can progress rapidly. Moreover, personalized treatments, based on the specific DNMT3A variants and the different pathways of their function loss, can be envisioned in the future.

The Impact of COVID-19 Infection on Patients with Severe Chronic Pulmonary Hypertension: A Prospective Study from a Single Referral Center.

Background and Objectives. COVID-19 infection has a significant burden on global morbidity and mortality, especially in elderly people and in patients with chronic respiratory and cardiovascular diseases, such as pulmonary hypertension (PH). We aimed to evaluate the impact of COVID-19 infection on patients diagnosed with severe chronic PH. Materials and Methods. A single-center prospective cohort study was performed. Patients were enrolled from 1 November 2020 to 31 December 2022. Follow-up was until 31 December 2023. Data were collected on PH diagnosis, clinical presentation, outcomes, brain natriuretic peptide (BNP) levels, pulmonary function test with lung diffusion capacity for carbon monoxide (DLCO), and computed tomography pulmonary angiography (CTPA) analysis. Results. During the 26 months of our study, 51 PH patients were diagnosed with COVID-19 infection. The majority, 44 (86.3%) of all COVID-19 infected patients, were treated on an outpatient basis, and 7 (13.7%) required hospitalization. During the follow-up period, 8 (15.7%) patients died: 4 (7.8%) due to complications of COVID-19 infection, and the other 4 (7.8%) died in the later stages of the follow-up period after recovery from acute COVID-19 infection. Therefore, the in-hospital mortality in our study was 43% (n = 3). As mentioned above, the overall mortality was 7.8% (n = 4). Higher BNP levels in the third month after COVID-19 were associated with higher mortality rates (p = 0.028). Lung function, including DLCO, did not significantly worsen with COVID-19. In our study, 24 patients (47.1%) were referred for a follow-up CTPA scan and one of them developed typical fibrotic lung changes after COVID-19. Conclusions. The incidence of COVID-19 infection in patients diagnosed with PH was 34%. In our patients with severe chronic PH, the overall mortality rate due to COVID-19 infection was low. Pulmonary fibrosis was a rare complication in our cohort. COVID-19 infection in severe PH may increase the risk of worsening chronic heart failure.

Rare c.302C>T TTR Variant Associated with Transthyretin Amyloidosis.

Background and Objectives: Hereditary transthyretin amyloidosis (ATTRv) is a rare disease caused by pathogenic variants in the transthyretin (TTR) gene. More than 140 different disease-causing variants in TTR have been reported. Only a few individuals with a rare TTR variant, c.302C>T, p.(Ala101Val) (historically known as p.(Ala81Val)), primarily associated with cardiac ATTRv, have been described. Therefore, our aim was to analyze the clinical characteristics of individuals with the identified c.302C>T TTR variant at our center. Materials and Methods: We analyzed data from individuals with ATTRv who were diagnosed and treated at Vilnius University Hospital Santaros Klinikos. ATTRv was confirmed by negative hematological analysis for monoclonal protein, positive tissue biopsy or bone scintigraphy and a pathogenic TTR variant. Results: During 2018-2021, the TTR NM_000371.3:c.302C>T, NP_000362.1:p.(Ala101Val) variant was found in one individual in a homozygous state and in three individuals in a heterozygous state. The age of onset of symptoms ranged from 44 to 74 years. The earliest onset of symptoms was in the individual with the homozygous variant. A history of carpal tunnel syndrome was identified in two individuals. On ECG, three individuals had low QRS voltage in limb leads. All individuals had elevated NT-proBNP and hsTroponine I levels on baseline laboratory tests and concentric left ventricular hypertrophy on transthoracic echocardiography. The individual with the homozygous c.302C>T TTR variant had the most pronounced polyneuropathy with tetraparesis. Other patients with the heterozygous variant had more significant amyloid cardiomyopathy. When screening family members, the c.302C>T TTR variant was identified in two phenotypically negative relatives at the ages of 33 and 47 years. Conclusions: c.302C>T is a rare TTR variant associated with ATTRv cardiomyopathy. The homozygous state of this variant was not reported before, and is associated with earlier disease onset and neurological involvement compared to the heterozygote state.