Genetic background of pediatric PAH in Spain and its clinical implications: data from the REHIPED Spanish Registry

Background

The genetic background of pulmonary arterial hypertension (PAH) in the Spanish pediatric population could be different from the genetic background described in other countries. Besides, clinical implications of a positive genetic result in the PAH pediatric population are not fully understood yet, and could result in the “reclassification” of patients from one PAH group to another type among the current pediatric classification.

Material and methods

Patients under 19 years at diagnosis included in the REHIPED registry from January 2011 to December 2021 were included. Clinical variables and genetical results were recorded. Succesive NGS panels involving up to 35 genes were used. After the results of the genetic testing, we analyzed differences in survival, and if patients “moved” to another category in the current Nice classification.

Results

In the selected cohort of 98 patients (56.1% female), median age at diagnosis was 7.1 years (IQr 1.5–14.7), and ethnicity as follows: Caucasian (81.6%), Romani (8.2%), others (10.2%) (Table 1). Before the genetic testing, patients had been classified as Idiopathic (53.1%), Congenital Heart Disease-PAH (30.6%), Heritable (5.1%), Pulmonary veno-oclusive disease (PVOD) 6.1%, and Multisystemic disorder associated with PAH (5.1%). Pathogenic or likely pathogenic variants were found in 44 of the screened patients (44.9%): BMPR2 (12 cases), EIF2AK4 (9), TBX4 (n=4), MECP2 (n=3), KCNK3 (n=2), FOXF1 (n=2), NFU1 (N=4), ACVRL1 (n=1), BMPR1B (n=1), CLBCI (n=1), GBE1 (n=1), GDF2 (n=1), SOX17 (n=1), VHL (n=1), and digenic pathogenic variant in ABCC8/SMAD1 (n=1). After genetic analysis, 28 patients (28.6%) were “reclassified” (Fig. 1, panel A), with HPAH, PVOD and multisystemic disorders increasing up to 18.4%, 8.2%, and 12.2%, respectively. Worse Survival from death or lung transplantation was observed in heritable PVOD and multisystemic disorders (Fig. 1, panel B).

Conclusions

The Spanish pediatric PAH population showed higher prevalence of EIF2AK4 than other pediatric registries. Genetic testing resulted in the “reclassification” of a significant number of patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Rio Hortega grant from the Spanish Ministry of Science and Innovation (Instituto de Salud Carlos III).

Genetic background in pediatric pulmonary arterial hypertension. Should we change the current recommendations for genetic testing?

Background

Pulmonary arterial hypertension (PAH) is a rare and severe disease, genetically predisposed in a high proportion of patients. PAH is subclassified in different subtypes depending on the underlying condition. Gene variants are more frequent among heritable or idiopathic forms. Nevertheless, pathogenic variants have been described across the entire spectrum of this disease. Evidence regarding genetics in pediatric PAH is scarce [1].

Purpose

Our aim is to describe the prevalence of significant gene mutations among a pediatric PAH cohort and to define specific data in the different subtypes.

Methods

Samples for genetic studies were obtained from blood tests of patients included in the Spanish National Registry of Pediatric Pulmonary Hypertension (REHIPED). Guardians signed informed consent before the inclusion in the study. Qualitative variables were compared by Chi-square test. Quantitative variables were assessed by Kruskal-Wallis, considering the asymmetric distribution of variables. STATA 14.0 was used for analyses.

Results

Sixty four patients were included between 2011 and 2021. Median age of the entire sample was 7.1 years (2.0–12.6) and 42.2% of them were male. There were significant differences in the age at diagnosis and race between the different included groups (table). Pathogenic or likely pathogenic variants were more frequent in familial pulmonary venooclusive disease (PVOD) and familial PAH cases. A similar percentage of mutations were found in idiopathic cases and in PAH associated with congenital heart disease (Figure). Gene variants in the gene encoding the bone morphogenetic protein receptor type 2 (BMPR2) were the most frequent mutations in the PAH familial cohort and there was also the most frequent finding in congenital heart disease and sporadic PAH, in conjunction with the TBX4 gene. Homozygous or compound heterozygous EIF2AK4 (eukaryotic translation initiation factor 2 a kinase 4) mutations were found in all the patients diagnosed with PVOD. Heritable PAH and PVOD cases were diagnosed more frequently after family screening.

Conclusions

This study shows a comparable proportion of pathogenic-likely pathogenic gene mutations in patients diagnosed of pulmonary arterial hypertension associated with congenital heart disease and idiopathic cases, with similar distribution of specific genes. BMPR2 and TBX 4 were the most frequent gene variants in this pediatric PAH population. BMPR2 and EIF2AK4 are the most common mutations in familial PAH and PVOD subtypes, respectively.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ACU holds a Rio Hortega Grant from the Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation.JAT and NG hold grants from FEDER (Federaciόn Española de Enfermedades Raras) and from the FCHP. Table 1. Characteristics of PAH subtypesFigure 1. PAH and ACMG classification.

[Prenatal screening of congenital heart defects in population at low risk of congenital defects. A reality today]

INTRODUCTION

We propose to demonstrate that it is possible to implement a valid (diagnostic sensitivity for major cardiac malformations 90%), and universal (applied to over 90% of pregnant women), prenatal screening method for congenital heart defects.

MATERIALS AND METHODS

Prospective study. A total of 12478 pregnant women were evaluated between January 2008 and December 2010. Congenital heart diseases were screened using fetal extended basic echocardiography (cardiac ultrasound).

RESULTS

The prevalence of birth defects in general and congenital heart disease was 2.5% (2.2-2.7%) and 0.9% (0.7-1%) respectively. Congenital heart disease had a higher rate of association with other structural abnormalities with 11.5% (5.6-17.4%), 21% for major congenital heart disease (9.9-32%), and chromosomal abnormalities of 15.9% (9.1-22.7%), with 32.6% for major congenital heart disease (19.8-45.3%). A fetal cardiac ultrasound assessment was performed on 99.2% of pregnant women. The fetal echocardiography is useful for the diagnosis of congenital heart disease in general, and major congenital heart disease, with a sensitivity of 42.8% (33.5-52.5%) and 90.4% (78.9-96.8%), respectively, and a specificity for both of 99.9% (99.8-99.9%).

CONCLUSIONS

It is possible to perform a valid prenatal and universal screening of major congenital heart disease.

[Synchronous adenocarcinoma and lymphoepithelioma-like carcinoma in the stomach: a case presentation and literature review]

Gastric cancer is one of the main causes of death in the world. In Venezuela, gastric tumors represent 37% of all malignant tumors of the digestive system, but only 1,6% to 3,1% of these cases are lymphoepithelioma-like carcinoma. Synchronous neoplastic lesions are also rare. The clinical case presented herein, a man with two synchronous tumor lesions, is the first of its kind in this country. Despite their incipient aspect, the histologic study reported two malignant tumors of epithelial origin: well-differentiated adenocarcinoma and lymphoepithelioma-like carcinoma.

Antibodies inhibiting Trypanosoma cruzi trans-sialidase activity in sera from human infections

Trans-sialidase, an enzyme that transfers sialic acid among macromolecules, has been implicated in invasion of host cells by Trypanosoma cruzi, the agent of Chagas' disease. Most antibodies produced in natural and experimental infections are directed to the highly antigenic C-terminal domain (shed acute-phase antigen). These antibodies do not inhibit the trans-sialidase activity, which is present in the N-terminal domain of the molecule. Antibodies able to inhibit trans-sialidase in sera from human infections have been found. TIA (trans-sialidase inhibition assay) was positive in sera from patients with acute and chronic infections. Healthy and congenitally infected infants born to mothers with Chagas' disease were also TIA-positive, but the antibody titers diminished within months after birth or after treatment. Thus, antibodies neutralizing trans-sialidase are detectable in most forms of T. cruzi human infections, and TIA may be useful in the diagnosis of Chagas' disease.

Evaluation of a simple screening test for the quality of drinking water systems

A simple and inexpensive assay for detection of H2S producing bacteria in drinking water was evaluated in Paraguay. Using an improved preparation procedure, results were basically temperature independent in the range of 22-37 degrees C and correlated well with the presence of total coliform bacteria (96%, 28 degrees C). The assay was not suitable for control of surface water and dug well water due to the frequent presence of non-faecal coliforms. However, it was very suitable for routine control of high quality water systems, like treated community water systems or deep-tube well water, where complete absence of coliforms is required. The H2S-test is very inexpensive and does not require a laboratory technician or special equipment. Its use permits a cost-effective routine control of high quality community water systems in developing countries. In addition, this test turned out to be an effective educational tool for heightening the awareness of people towards dangers of unclean drinking water.