2-29694909-G-A

Position:

• chr2-29694909-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The ENST00000389048.8(ALK):​c.893C>T​(p.Ala298Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. 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. A298G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALK ENST00000389048.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.20

Genes affected

ALK (HGNC:427): (ALK receptor tyrosine kinase) This gene encodes a receptor tyrosine kinase, which belongs to the insulin receptor superfamily. This protein comprises an extracellular domain, an hydrophobic stretch corresponding to a single pass transmembrane region, and an intracellular kinase domain. It plays an important role in the development of the brain and exerts its effects on specific neurons in the nervous system. This gene has been found to be rearranged, mutated, or amplified in a series of tumours including anaplastic large cell lymphomas, neuroblastoma, and non-small cell lung cancer. The chromosomal rearrangements are the most common genetic alterations in this gene, which result in creation of multiple fusion genes in tumourigenesis, including ALK (chromosome 2)/EML4 (chromosome 2), ALK/RANBP2 (chromosome 2), ALK/ATIC (chromosome 2), ALK/TFG (chromosome 3), ALK/NPM1 (chromosome 5), ALK/SQSTM1 (chromosome 5), ALK/KIF5B (chromosome 10), ALK/CLTC (chromosome 17), ALK/TPM4 (chromosome 19), and ALK/MSN (chromosome X).[provided by RefSeq, Jan 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3283257).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALK	NM_004304.5	c.893C>T	p.Ala298Val	missense_variant	3/29	ENST00000389048.8	NP_004295.2
ALK	XR_001738688.3	n.1820C>T		non_coding_transcript_exon_variant	3/18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALK	ENST00000389048.8	c.893C>T	p.Ala298Val	missense_variant	3/29	1	NM_004304.5	ENSP00000373700	P1
ALK	ENST00000618119.4	c.-239C>T		5_prime_UTR_variant	2/28	5		ENSP00000482733

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neuroblastoma, susceptibility to, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 27, 2017

In summary, this variant has uncertain impact on ALK function. The available evidence is currently insufficient to determine its role 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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with a ALK-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with valine at codon 298 of the ALK protein (p.Ala298Val). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.082	T
BayesDel_noAF	Benign	-0.36
CADD	Benign	19
DANN	Uncertain	1.0
DEOGEN2	Benign	0.060	T
Eigen	Benign	0.086
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.76	D
LIST_S2	Benign	0.73	T
M_CAP	Benign	0.057	D
MetaRNN	Benign	0.33	T
MetaSVM	Benign	-0.49	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	D;N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.42	N
REVEL	Benign	0.24
Sift	Benign	0.49	T
Sift4G	Benign	0.20	T
Polyphen		0.92	P
Vest4		0.53
MutPred		0.072		Loss of phosphorylation at S299 (P = 0.2149);
MVP		0.70
MPC		0.19
ClinPred		0.57	D
GERP RS		5.1
Varity_R		0.055
gMVP		0.25

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: rs750435024; hg19: chr2-29917775;