2-29275443-G-A

Position:

• chr2-29275443-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_004304.5(ALK):​c.1871C>T​(p.Ala624Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,884 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A624P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALK NM_004304.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.30

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALK	NM_004304.5	c.1871C>T	p.Ala624Val	missense_variant	10/29	ENST00000389048.8
ALK	XR_001738688.3	n.2798C>T		non_coding_transcript_exon_variant	10/18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALK	ENST00000389048.8	c.1871C>T	p.Ala624Val	missense_variant	10/29	1	NM_004304.5	P1
ALK	ENST00000618119.4	c.740C>T	p.Ala247Val	missense_variant	9/28	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461884 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neuroblastoma, susceptibility to, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 29, 2023

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. 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 disruptive. ClinVar contains an entry for this variant (Variation ID: 581121). This variant has not been reported in the literature in individuals affected with ALK-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 624 of the ALK protein (p.Ala624Val). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 04, 2024

The p.A624V variant (also known as c.1871C>T), located in coding exon 10 of the ALK gene, results from a C to T substitution at nucleotide position 1871. The alanine at codon 624 is replaced by valine, an amino acid with similar properties. This amino acid position is conserved. 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	Uncertain	0.41
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Benign	-0.21
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.13	T;.
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Benign	0.025	T
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Benign	-0.97	T
MutationAssessor	Uncertain	2.2	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-2.3	N;.
REVEL	Benign	0.18
Sift	Uncertain	0.0010	D;.
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.99	D;.
Vest4		0.89
MutPred		0.83		Gain of sheet (P = 0.0221);.;
MVP		0.57
MPC		0.62
ClinPred		0.94	D
GERP RS		4.2
Varity_R		0.48
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs906659904; hg19: chr2-29498309;