Nozari A, Aghaei-Moghadam E, Zeinaloo A, Alavi A, Ghasemi Firouzabdi S, Minaee S, Eskandari Hesari M, Behjati F. A Pathogenic Homozygous Mutation in The Pleckstrin Homology Domain of RASA1 Is Responsible for Familial
Tricuspid Atresia in An Iranian Consanguineous Family.
Cell J 2018;
21:70-77. [PMID:
30507091 PMCID:
PMC6275424 DOI:
10.22074/cellj.2019.5734]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/21/2018] [Indexed: 11/28/2022]
Abstract
Objective
Tricuspid atresia (TA) is a rare life-threatening form of congenital heart defect (CHD). The genetic
mechanisms underlying TA are not clearly understood. According to previous studies, the endocardial cushioning event,
as the primary sign of cardiac valvulogenesis, is governed by several overlapping signaling pathways including Ras/
ERK pathway. RASA1, a regulator of cardiovascular development, is involved in this pathway and its haploinsufficiency
(due to heterozygous mutations) has been identified as the underlying etiology of the autosomal dominant capillary
malformation/arteriovenous malformation (CM/AVM).
Materials and Methods
In this prospective study, we used whole exome sequencing (WES) followed by serial
bioinformatics filtering steps for two siblings with TA and early onset CM. Their parents were consanguineous which
had a history of recurrent abortions. Patients were carefully assessed to exclude extra-cardiac anomalies.
Results
We identified a homozygous RASA1 germline mutation, c.1583A>G (p.Tyr528Cys) in the family. This mutation
lies in the pleckstrin homology (PH) domain of the gene. The parents who were heterozygous for this variant displayed
CM.
Conclusion
This is the first study reporting an adverse phenotypic outcome of a RASA1 homozygous mutation.
Here, we propose that the phenotypic consequence of the homozygous RASA1 p.Tyr528Cys mutation is more serious
than the heterozygous type. This could be responsible for the TA pathogenesis in our patients. We strongly suggest
that parents with CM/AVM should be investigated for RASA1 heterozygous mutations. Prenatal diagnosis and fetal
echocardiography should also be carried out in the event of pregnancy in heterozygous parents.
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