rs1555383471

Positions:

• chr14-104773291-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001382430.1(AKT1):​c.917T>C​(p.Met306Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M306V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: AKT1 NM_001382430.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.12

Genes affected

AKT1 (HGNC:391): (AKT serine/threonine kinase 1) This gene encodes one of the three members of the human AKT serine-threonine protein kinase family which are often referred to as protein kinase B alpha, beta, and gamma. These highly similar AKT proteins all have an N-terminal pleckstrin homology domain, a serine/threonine-specific kinase domain and a C-terminal regulatory domain. These proteins are phosphorylated by phosphoinositide 3-kinase (PI3K). AKT/PI3K forms a key component of many signalling pathways that involve the binding of membrane-bound ligands such as receptor tyrosine kinases, G-protein coupled receptors, and integrin-linked kinase. These AKT proteins therefore regulate a wide variety of cellular functions including cell proliferation, survival, metabolism, and angiogenesis in both normal and malignant cells. AKT proteins are recruited to the cell membrane by phosphatidylinositol 3,4,5-trisphosphate (PIP3) after phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) by PI3K. Subsequent phosphorylation of both threonine residue 308 and serine residue 473 is required for full activation of the AKT1 protein encoded by this gene. Phosphorylation of additional residues also occurs, for example, in response to insulin growth factor-1 and epidermal growth factor. Protein phosphatases act as negative regulators of AKT proteins by dephosphorylating AKT or PIP3. The PI3K/AKT signalling pathway is crucial for tumor cell survival. Survival factors can suppress apoptosis in a transcription-independent manner by activating AKT1 which then phosphorylates and inactivates components of the apoptotic machinery. AKT proteins also participate in the mammalian target of rapamycin (mTOR) signalling pathway which controls the assembly of the eukaryotic translation initiation factor 4F (eIF4E) complex and this pathway, in addition to responding to extracellular signals from growth factors and cytokines, is disregulated in many cancers. Mutations in this gene are associated with multiple types of cancer and excessive tissue growth including Proteus syndrome and Cowden syndrome 6, and breast, colorectal, and ovarian cancers. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), AKT1. . Gene score misZ 3.4778 (greater than the threshold 3.09). Trascript score misZ 4.2155 (greater than threshold 3.09). GenCC has associacion of gene with Proteus syndrome, Cowden disease, Cowden syndrome 6.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AKT1	NM_001382430.1	c.917T>C	p.Met306Thr	missense_variant	11/15	ENST00000649815.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AKT1	ENST00000649815.2	c.917T>C	p.Met306Thr	missense_variant	11/15		NM_001382430.1	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461866 Hom.: 0 Cov.: 36 AF XY: 0.00000275 AC XY: 2 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cowden syndrome 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 16, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 540888). This variant has not been reported in the literature in individuals affected with AKT1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 306 of the AKT1 protein (p.Met306Thr). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.66
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.010
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.29	T;T;T;T;T;T;T
Eigen	Benign	-0.57
Eigen_PC	Benign	-0.38
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.78	.;.;.;.;.;.;T
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.67	D;D;D;D;D;D;D
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	-0.88	N;N;N;N;N;N;N
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Benign	1.4	N;N;N;N;N;.;N
REVEL	Uncertain	0.33
Sift	Benign	1.0	T;T;T;T;T;.;T
Sift4G	Benign	1.0	T;T;T;T;T;.;T
Polyphen		0.0010	B;B;B;B;B;B;B
Vest4		0.83
MutPred		0.73		Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);Gain of catalytic residue at A304 (P = 0);
MVP		0.88
MPC		3.3
ClinPred		0.92	D
GERP RS		3.4
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.6
Varity_R		0.67
gMVP		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1555383471; hg19: chr14-105239628; COSMIC: COSV62576765; COSMIC: COSV62576765;