Dataset Information

Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience.

ABSTRACT:

Background

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in more than 90% of the patients undergoing molecular testing. The identification of variants of unknown significance is often seen as a challenge in clinical practice that makes family screening and genetic counseling difficult. Here, we show that the implementation of cDNA analysis to assess the effect of splice site variants on mRNA splicing is a powerful tool.

Methods

Gene panel sequencing of genes associated with HHT and other arteriovenous malformation-related syndromes was performed. To evaluate the effect of the splice site variants, cDNA analysis of ENG and ACVRL1 genes was carried out.

Results

three novel splice site variants were identified in ENG (c.68-2A > T and c.1311+4_1311+8del) and ACVLR1 (c.526-6C > G) genes correspondingly in three individuals with HHT that met ≥ 3 Curaçao criteria. All three variants led to an aberrant splicing inducing exon skipping (ENG:c.68-2A > T and ACVRL1:c.526-6C > G) or intron retention (ENG:c.1311+4_1311+8del) allowing the confirmation of the predicted effect on splicing and the reclassification from unknown significance to pathogenic/likely pathogenic of two of them.

Conclusions

RNA analysis should be performed to assess and/or confirm the impact of variants on splicing. The molecular diagnosis of HHT patients is crucial to allow family screening and accurate genetic counseling. A multidisciplinary approach including clinicians and geneticists is crucial when dealing with patients with rare diseases.

SUBMITTER: Aguilera C

PROVIDER: S-EPMC10048779 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature

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Publications

Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience.

Aguilera Cinthia C Padró-Miquel Ariadna A Esteve-Garcia Anna A Cerdà Pau P Torres-Iglesias Raquel R Llecha Núria N Riera-Mestre Antoni A

Genes 20230322 3

<h4>Background</h4>Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (<i>ENG</i>) and activin A receptor type II-like 1 (<i>ACVRL1</i>) genes are detected in more than 90% of the patients undergoing molecular testing. The identification of variants of unknown significance is often seen as a challenge in clinical practice that makes family screening and genetic counseling difficult. Here, we show ...[more]

PMID: 36981042

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Project description:Background and purposeThe presence of malformations of cortical development in patients with hereditary hemorrhagic telangiectasia has been reported on previous occasions. We evaluated a sample of adults with hereditary hemorrhagic telangiectasia for the presence of malformations of cortical development, spatial coincidence of malformations of cortical development and AVMs, and the coincidence of brain and pulmonary AVMs.Materials and methodsA total of 141 patients 18 years of age or older who were referred to the Augusta University hereditary hemorrhagic telangiectasia clinic and underwent brain MR imaging between January 19, 2018, and December 3, 2020, were identified. MR imaging examinations were reviewed retrospectively by 2 experienced neuroradiologists, and the presence of malformations of cortical development and AVMs was confirmed by consensus. Demographic and clinical information was collected for each case, including age, sex, hereditary hemorrhagic telangiectasia status by the Curacao Criteria, mutation type, presence of malformations of cortical development, presence of brain AVMs, presence of pulmonary AVMs, and a history of seizures or learning disabilities.ResultsFive of 141 (3.5%) patients with hereditary hemorrhagic telangiectasia had malformations of cortical development. Two of the 5 patients with polymicrogyria also had closed-lip schizencephaly. One of the patients had a porencephalic cavity partially lined with heterotopic GM. The incidence of spatially coincident polymicrogyria and brain AVMs was 40% (2/5 cases). Of the patients with hereditary hemorrhagic telangiectasia and malformations of cortical development, 4/5 (80%) had pulmonary AVMs and 2/5 (40%) had brain AVMs.ConclusionsTo our knowledge, we are the first group to report the presence of schizencephaly in patients with hereditary hemorrhagic telangiectasia. The presence of schizencephaly and porencephaly lends support to the hypothesis of regional in utero cerebral hypoxic events as the etiology of malformations of cortical development in hereditary hemorrhagic telangiectasia.

Project description:Hereditary hemorrhagic telangiectasia is a rare autosomal dominant vascular disease defined by the presence of mucosal and cutaneous telangiectasia and visceral arterio-venous malformations. The latter are abnormal capillary-free direct communications between the pulmonary and systemic circulations with the following consequences: arterial hypoxemia caused by right-to-left shunts; paradoxical embolism with transient ischemic attack or stroke and brain abscess caused by the absence of the normally filtering capillary bed; and hemoptysis or hemothorax due to the rupture of the thin-walled arterio-venous malformations (particularly during pregnancy). It is frequently underdiagnosed, commonly presenting as complications from shunting through arterio-venous malformations: dyspnea, chronic bleeding, or embolism. Arterio-venous malformations are present not only in the lungs, but can also be found in the liver, central nervous system (mainly in the brain), nasal mucosa, or the gastrointestinal tract. The first choice of therapy is embolization of the afferent arteries of the arterio-venous malformations, a minimally invasive procedure with a high efficacy, a low morbidity, and low mortality. Other therapeutic modalities are surgery (resection) or stereotactic radiosurgery (using radiation). Routine screening for arterio-venous malformations is indicated in patients diagnosed with this condition and can prevent severe complications such as acute hemorrhages, brain abscesses, or strokes. Clinicians should provide a long-term follow-up for patients with arterio-venous malformations, in an effort to detect their growth or reperfusion in case of previously treated malformations. In spite of two experts' consensuses, it still possesses multiple therapeutic challenges for physicians, as several aspects regarding the screening and management of arterio-venous malformations still remain controversial. Multidisciplinary teams are especially useful in complex cases.

Dataset Information

Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience.

Background

Methods

Results

Conclusions

Publications

Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience.

Similar Datasets

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