Heterozygous missense mutations in NFATC1 are associated with atrioventricular septal defect

Abstract

Atrioventricular septal defect (AVSD) may occur as part of a complex disorder (e.g., Down syndrome, heterotaxy), or as isolate cardiac defect. Multiple lines of evidence support a role of calcineurin/NFAT signaling in AVSD, and mutations in CRELD1, a protein functioning as a regulator of calcineurin/NFAT signaling have been reported in a small fraction of affected subjects. In this study, 22 patients with isolated AVSD and 38 with AVSD and heterotaxy were screened for NFATC1 gene mutations. Sequence analysis identified three missense variants in three individuals, including a subject with isolated AVSD [p.(Ala367Val)], an individual with AVSD and heterotaxy [p.(Val210Met)], and a subject with AVSD, heterotaxy, and oculo-auriculo-vertebral spectrum (OAVS) [p.(Ala696Thr)], respectively. The latter was also heterozygous for a missense change in TBX1 [p.(Pro86Leu)]. Targeted resequencing of genes associated with AVSD, heterotaxy, or OAVS excluded additional hits in the three mutation-positive subjects. Functional characterization of NFATC1 mutants documented defective nuclear translocation and decreased transcriptional transactivation activity. When expressed in zebrafish, the three NFATC1 mutants caused cardiac looping defects and altered atrioventricular canal patterning, providing evidence of their functional relevance in vivo. Our findings support a role of defective NFATC1 function in the etiology of isolated and heterotaxy-related AVSD.

Genetics of atrioventricular canal defects

“…The fact that defective NFATC1 function could contribute to isolated AVCD was also demonstrated by a recent work by Ferese et al [114]. The authors reported missense rare variants in NFATC1 gene in two patients with non-syndromic AVCD and in one syndromic patient with AVCD in the context of heterotaxia and polysplenia with left isomerism.…”

“…Experimental studies in zebrafish have demonstrated that NFATC1 variants have a great impact on cardiogenesis, affecting specifically cardiac looping process. Interestingly, a link between NFATC1 and CRELD1 genes has been noted, since CRELD1 has been shown to be a master regulator of calcineurin/NFATC1 signaling [114].…”

Prevalence, Type, and Molecular Spectrum of NF1 Mutations in Patients with Neurofibromatosis Type 1 and Congenital Heart Disease

“…Parallel sequencing libraries were prepared using either the HaloPlexHS target enrichment kit (Agilent, Santa Clara, CA, USA) or the SureSelect target enrichment system (Agilent, Santa Clara, CA, USA), whereas sequencing was carried out on a MiSeq platform (Illumina, San Diego, CA, USA). Variant calling and data analyses were performed using an in-house implemented pipeline, as previously described [36]. All variants detected by NGS were validated by Sanger sequencing, as previously reported [7].…”

On Zebrafish Disease Models and Matters of the Heart

“…Atrioventricular septal defects (AVSD) also represent abnormalities in atrioventricular valves, and atrial and ventricular septa. The study by Ferese et al, identified NFATC1 rare variants in a small but significant proportion of cases from two cohorts of AVSD patients [87]. The authors observed cardiac looping defects and altered atrioventricular canal patterning in the nfatc1 zebrafish mutants, providing evidence of their functional relevance in vivo and supporting a role of defective NFATC1 function in the etiology of AVSD.…”