2-70692447-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The NM_001617.4(ADD2):c.661G>A(p.Asp221Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000745 in 1,609,816 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: ADD2 NM_001617.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.68

Genes affected

ADD2 (HGNC:244): (adducin 2) Adducins are heteromeric proteins composed of different subunits referred to as adducin alpha, beta and gamma. The three subunits are encoded by distinct genes and belong to a family of membrane skeletal proteins involved in the assembly of spectrin-actin network in erythrocytes and at sites of cell-cell contact in epithelial tissues. While adducins alpha and gamma are ubiquitously expressed, the expression of adducin beta is restricted to brain and hematopoietic tissues. Adducin, originally purified from human erythrocytes, was found to be a heterodimer of adducins alpha and beta. Polymorphisms resulting in amino acid substitutions in these two subunits have been associated with the regulation of blood pressure in an animal model of hypertension. Heterodimers consisting of alpha and gamma subunits have also been described. Structurally, each subunit is comprised of two distinct domains. The amino-terminal region is protease resistant and globular in shape, while the carboxy-terminal region is protease sensitive. The latter contains multiple phosphorylation sites for protein kinase C, the binding site for calmodulin, and is required for association with spectrin and actin. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jun 2010]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.856
• BS2: High AC in GnomAdExome at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ADD2	NM_001617.4	c.661G>A	p.Asp221Asn	missense_variant	7/16	ENST00000264436.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ADD2	ENST00000264436.9	c.661G>A	p.Asp221Asn	missense_variant	7/16	1	NM_001617.4	P2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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

GnomAD3 exomes AF: 0.0000202 AC: 5 AN: 247334 Hom.: 0 AF XY: 0.0000224 AC XY: 3 AN XY: 133738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000294

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000665

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000179

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000755 AC: 11 AN: 1457634 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 724816

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000226

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000350

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000541

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74356

Gnomad4 AFR AF: 0.0000241

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

Alfa AF: 0.0000371 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 11, 2023

The c.661G>A (p.D221N) alteration is located in exon 7 (coding exon 5) of the ADD2 gene. This alteration results from a G to A substitution at nucleotide position 661, causing the aspartic acid (D) at amino acid position 221 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.29
Cadd	Pathogenic	28
Dann	Pathogenic	1.0
DEOGEN2	Benign	0.41	T;T;.;.;.;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.061	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D
MetaSVM	Benign	-0.33	T
MutationAssessor	Pathogenic	3.4	M;M;M;.;M;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-4.5	D;D;D;D;D;D;D
REVEL	Uncertain	0.51
Sift	Pathogenic	0.0	D;D;D;D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;.;D;D;.
Polyphen		1.0	D;D;D;.;.;.;.
Vest4		0.87
MVP		0.65
MPC		1.3
ClinPred		0.98	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.76
gMVP		0.80

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: rs781893870; hg19: chr2-70919579; COSMIC: COSV52469857; COSMIC: COSV52469857;