5-138781928-A-G

Position:

• chr5-138781928-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_001903.5(CTNNA1):​c.4A>G​(p.Thr2Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000131 in 152,216 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 32)
• Consequence: CTNNA1 NM_001903.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.71

Genes affected

CTNNA1 (HGNC:2509): (catenin alpha 1) This gene encodes a member of the catenin family of proteins that play an important role in cell adhesion process by connecting cadherins located on the plasma membrane to the actin filaments inside the cell. The encoded mechanosensing protein contains three vinculin homology domains and undergoes conformational changes in response to cytoskeletal tension, resulting in the reconfiguration of cadherin-actin filament connections. Certain mutations in this gene cause butterfly-shaped pigment dystrophy. [provided by RefSeq, May 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a modified_residue N-acetylthreonine (size 0) in uniprot entity CTNA1_HUMAN
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CTNNA1. . Gene score misZ 3.6624 (greater than the threshold 3.09). Trascript score misZ 4.1669 (greater than threshold 3.09). GenCC has associacion of gene with patterned macular dystrophy 2, CTNNA1-related diffuse gastric and lobular breast cancer syndrome, patterned macular dystrophy, hereditary nonpolyposis colon cancer.
• BP4: Computational evidence support a benign effect (MetaRNN=0.27063406).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CTNNA1	NM_001903.5	c.4A>G	p.Thr2Ala	missense_variant	2/18	ENST00000302763.12	NP_001894.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CTNNA1	ENST00000302763.12	c.4A>G	p.Thr2Ala	missense_variant	2/18	1	NM_001903.5	ENSP00000304669.7

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152216 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152216 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74362

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 14, 2023

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 2 of the CTNNA1 protein (p.Thr2Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CTNNA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1054328). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 25, 2023

The p.T2A variant (also known as c.4A>G), located in coding exon 1 of the CTNNA1 gene, results from an A to G substitution at nucleotide position 4. The threonine at codon 2 is replaced by alanine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.072
BayesDel_addAF	Benign	0.0042	T
BayesDel_noAF	Benign	-0.23
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.029	T;T;T;T;T;T;T;T;.;T
Eigen	Benign	-0.085
Eigen_PC	Benign	0.13
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.72	T;T;T;T;T;T;T;T;T;.
M_CAP	Benign	0.022	T
MetaRNN	Benign	0.27	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.83	T
MutationAssessor	Benign	0.90	.;.;.;.;.;.;L;.;.;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-1.3	N;N;N;N;N;.;N;N;N;N
REVEL	Benign	0.078
Sift	Benign	0.17	T;T;T;T;T;.;T;T;T;T
Sift4G	Uncertain	0.028	D;D;D;T;D;D;T;T;T;D
Polyphen		0.0060, 0.037	.;.;.;.;.;B;B;.;.;B
Vest4		0.39, 0.31, 0.39
MutPred		0.20		Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);
MVP		0.66
MPC		0.13
ClinPred		0.54	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.060
gMVP		0.47

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

Publications

LitVar

Other links and lift over

dbSNP: rs1248704890; hg19: chr5-138117617;