5-173233107-G-T

Variant names:

• chr5-173233107-G-T
• rs397516909
• NM_004387.4:c.437C>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004387.4(NKX2-5):​c.437C>A​(p.Ser146*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. S146S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NKX2-5 NM_004387.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.97
• Publications: 1 publications found

Genes affected

NKX2-5 (HGNC:2488): (NK2 homeobox 5) This gene encodes a homeobox-containing transcription factor. This transcription factor functions in heart formation and development. Mutations in this gene cause atrial septal defect with atrioventricular conduction defect, and also tetralogy of Fallot, which are both heart malformation diseases. Mutations in this gene can also cause congenital hypothyroidism non-goitrous type 5, a non-autoimmune condition. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2009]

NKX2-5 Gene-Disease associations (from GenCC):

• atrial septal defect 7

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Orphanet
• hypothyroidism, congenital, nongoitrous, 5

  Inheritance: AD, Unknown Classification: DEFINITIVE, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• NKX2.5-related congenital, conduction and myopathic heart disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tetralogy of fallot

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• conotruncal heart malformations

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• athyreosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial bicuspid aortic valve

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated congenital asplenia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 68 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-173233107-G-T is Pathogenic according to our data. Variant chr5-173233107-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1417309.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NKX2-5	NM_004387.4	c.437C>A	p.Ser146*	stop_gained	Exon 2 of 2	ENST00000329198.5	NP_004378.1
NKX2-5	NM_001166176.2	c.*236C>A		3_prime_UTR_variant	Exon 2 of 2		NP_001159648.1
NKX2-5	NM_001166175.2	c.*390C>A		3_prime_UTR_variant	Exon 2 of 2		NP_001159647.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NKX2-5	ENST00000329198.5	c.437C>A	p.Ser146*	stop_gained	Exon 2 of 2	1	NM_004387.4	ENSP00000327758.4
NKX2-5	ENST00000424406.2	c.*390C>A		3_prime_UTR_variant	Exon 2 of 2	1		ENSP00000395378.2
NKX2-5	ENST00000521848.1	c.*236C>A		3_prime_UTR_variant	Exon 2 of 2	2		ENSP00000427906.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Atrial septal defect 7 Pathogenic:1

Aug 23, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 1417309). This variant has not been reported in the literature in individuals affected with NKX2-5-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser146*) in the NKX2-5 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 179 amino acid(s) of the NKX2-5 protein. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the NKX2-5 protein in which other variant(s) (p.Ala262Argfs*32) have been determined to be pathogenic (PMID: 22920929). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. -

Cardiovascular phenotype Pathogenic:1

Feb 21, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S146* pathogenic mutation (also known as c.437C>A), located in coding exon 2 of the NKX2-5 gene, results from a C to A substitution at nucleotide position 437. This changes the amino acid from a serine to a stop codon within coding exon 2. This alteration occurs at the 3' terminus of theNKX2-5 gene, is not expected to trigger nonsense-mediated mRNA decay, and impacts the last 55% of the protein. However, premature stop codons are typically deleterious in nature, a significant portion of the protein is affected, and the impacted region is critical for protein function (Ambry internal data). This variant was identified in one or more individuals with features consistent with NKX2-5 related congenital heart disease, conduction disease, and cardiomyopathy, and segregated with disease in at least one family (Helm BM et al. Cardiol Young, 2024 Mar;34:654-658; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	43
DANN	Uncertain	0.99
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		10
Vest4		0.97
GERP RS		4.2
Mutation Taster		=6/194	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs397516909; hg19: chr5-172660110;