rs121918620

chr1-160128761-C-Gchr1-160128761-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000702.4(ATP1A2):c.1127C>G(p.Thr376Arg) variant causes a missense 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. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T376M) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ATP1A2 NM_000702.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.84

Genes affected

ATP1A2 (HGNC:800): (ATPase Na+/K+ transporting subunit alpha 2) The protein encoded by this gene belongs to the family of P-type cation transport ATPases, and to the subfamily of Na+/K+ -ATPases. Na+/K+ -ATPase is an integral membrane protein responsible for establishing and maintaining the electrochemical gradients of Na and K ions across the plasma membrane. These gradients are essential for osmoregulation, for sodium-coupled transport of a variety of organic and inorganic molecules, and for electrical excitability of nerve and muscle. This enzyme is composed of two subunits, a large catalytic subunit (alpha) and a smaller glycoprotein subunit (beta). The catalytic subunit of Na+/K+ -ATPase is encoded by multiple genes. This gene encodes an alpha 2 subunit. Mutations in this gene result in familial basilar or hemiplegic migraines, and in a rare syndrome known as alternating hemiplegia of childhood. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000702.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-160128761-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 12930.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, ATP1A2
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• PP5: Variant 1-160128761-C-G is Pathogenic according to our data. Variant chr1-160128761-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 204885.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ATP1A2	NM_000702.4	c.1127C>G	p.Thr376Arg	missense_variant	9/23	ENST00000361216.8
ATP1A2	XM_047421286.1	c.236C>G	p.Thr79Arg	missense_variant	2/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ATP1A2	ENST00000361216.8	c.1127C>G	p.Thr376Arg	missense_variant	9/23	1	NM_000702.4	P1
ATP1A2	ENST00000392233.7	c.1127C>G	p.Thr376Arg	missense_variant	9/23	5
ATP1A2	ENST00000447527.1	c.260C>G	p.Thr87Arg	missense_variant	2/16	2
ATP1A2	ENST00000472488.5	n.1230C>G		non_coding_transcript_exon_variant	9/20	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 04, 2013	p.Thr376Arg (ACG>AGG): c.1127 C>G in exon 9 of the ATP1A2 gene (NM_000702.3). The Thr376Arg missense change has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Thr376Arg is a non-conservative amino acid substitution of an uncharged Threonine residue with a positively charged Arginine residue at a highly conserved position in the intracellular loop between the M4 and M5 transmembrane domains. A different amino acid substitution at the same position (Thr376Met) co-segregated with familial hemiplegic migraine in two unrelated families and was reported to impair catalytic activity, confirming the functional importance of this position in the protein (Riant et al., 2005; Tavraz et al., 2008). The variant is found in EPILEPSY panel(s). -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 02, 2020	- -

Familial hemiplegic migraine Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 03, 2020

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Thr376 amino acid residue in ATP1A2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16088919, 17952365, 18728015). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed in individual(s) with clinical features of alternating hemiplegia of childhood (Invitae). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 204885). This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with arginine at codon 376 of the ATP1A2 protein (p.Thr376Arg). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	28
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.72	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.3	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-5.1	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.98
MutPred		0.89		Gain of MoRF binding (P = 0.0245);Gain of MoRF binding (P = 0.0245);
MVP		0.98
MPC		1.9
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.89
gMVP		1.0

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: rs121918620; hg19: chr1-160098551;