rs1553397495

Variant names:

• chr2-29239799-C-T
• rs1553397495
• NM_004304.5:c.2236G>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_004304.5(ALK):​c.2236G>A​(p.Gly746Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,590 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G746G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ALK NM_004304.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.19
• Publications: 0 publications found

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]

ALK Gene-Disease associations (from GenCC):

• neuroblastoma, susceptibility to, 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.31808117).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALK	NM_004304.5	c.2236G>A	p.Gly746Ser	missense_variant	Exon 13 of 29	ENST00000389048.8	NP_004295.2
ALK	XR_001738688.3	n.3163G>A		non_coding_transcript_exon_variant	Exon 13 of 18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALK	ENST00000389048.8	c.2236G>A	p.Gly746Ser	missense_variant	Exon 13 of 29	1	NM_004304.5	ENSP00000373700.3
ALK	ENST00000618119.4	c.1105G>A	p.Gly369Ser	missense_variant	Exon 12 of 28	5		ENSP00000482733.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461590 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727098

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53184

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111958

Other (OTH) AF: 0.00 AC: 0 AN: 60386

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neuroblastoma, susceptibility to, 3 Uncertain:2

Jul 02, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 746 of the ALK protein (p.Gly746Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ALK-related conditions. ClinVar contains an entry for this variant (Variation ID: 538270). 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. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Dec 04, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G746S variant (also known as c.2236G>A), located in coding exon 13 of the ALK gene, results from a G to A substitution at nucleotide position 2236. The glycine at codon 746 is replaced by serine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Uncertain	0.091	D
BayesDel_noAF	Benign	-0.11
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.31	T;.
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.32	T;T
MetaSVM	Benign	-0.45	T
MutationAssessor	Uncertain	2.6	M;.
PhyloP100		3.2
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.3	D;.
REVEL	Benign	0.24
Sift	Benign	0.040	D;.
Sift4G	Benign	0.13	T;T
Polyphen		0.98	D;.
Vest4		0.43
MutPred		0.25		Gain of relative solvent accessibility (P = 0.0023);.;
MVP		0.72
MPC		0.70
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.32
gMVP		0.67
Mutation Taster		=79/21	polymorphism

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

Other links and lift over

dbSNP: rs1553397495; hg19: chr2-29462665;