2-29920326-C-T

Position:

• chr2-29920326-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_004304.5(ALK):​c.334G>A​(p.Ala112Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000214 in 1,401,430 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ALK NM_004304.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.755

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06237471).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALK	NM_004304.5	c.334G>A	p.Ala112Thr	missense_variant	1/29	ENST00000389048.8	NP_004295.2
ALK	XR_001738688.3	n.1261G>A		non_coding_transcript_exon_variant	1/18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALK	ENST00000389048.8	c.334G>A	p.Ala112Thr	missense_variant	1/29	1	NM_004304.5	ENSP00000373700.3
ENSG00000288553	ENST00000669284.1	n.157+34923G>A		intron_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000214 AC: 3 AN: 1401430 Hom.: 0 Cov.: 31 AF XY: 0.00000145 AC XY: 1 AN XY: 691964

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: 0.00000277

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Sep 20, 2023

This variant has not been reported in the literature in individuals affected with ALK-related conditions. This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 112 of the ALK protein (p.Ala112Thr). This variant is not present in population databases (gnomAD no frequency). ClinVar contains an entry for this variant (Variation ID: 855320). 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 tolerated. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 12, 2023

The p.A112T variant (also known as c.334G>A), located in coding exon 1 of the ALK gene, results from a G to A substitution at nucleotide position 334. The alanine at codon 112 is replaced by threonine, 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	Benign	0.073
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	0.24
DANN	Uncertain	0.97
DEOGEN2	Benign	0.097	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.024	N
LIST_S2	Benign	0.37	T
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.062	T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	0.0	N
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-0.35	N
REVEL	Benign	0.043
Sift	Benign	0.16	T
Sift4G	Benign	0.11	T
Polyphen		0.0	B
Vest4		0.083
MutPred		0.17		Gain of glycosylation at A112 (P = 0.0073);
MVP		0.34
MPC		0.16
ClinPred		0.048	T
GERP RS		-0.20
Varity_R		0.032
gMVP		0.081

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: rs1060500227; hg19: chr2-30143192; COSMIC: COSV66555910;