chr2-29275403-G-A

Position:

• chr2-29275403-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6 BP7

The NM_004304.5(ALK):​c.1911C>T​(p.Thr637Thr) variant causes a splice region, synonymous 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. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALK NM_004304.5 splice_region, synonymous
• Scores: Splicing: ADA: 0.004020
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 1.11

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 (BayesDel_noAF=-0.39).
• BP6: Variant 2-29275403-G-A is Benign according to our data. Variant chr2-29275403-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 538266.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.
• BP7: Synonymous conserved (PhyloP=1.11 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALK	NM_004304.5	c.1911C>T	p.Thr637Thr	splice_region_variant, synonymous_variant	10/29	ENST00000389048.8	NP_004295.2
ALK	XR_001738688.3	n.2838C>T		splice_region_variant, non_coding_transcript_exon_variant	10/18

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALK	ENST00000389048.8	c.1911C>T	p.Thr637Thr	splice_region_variant, synonymous_variant	10/29	1	NM_004304.5	ENSP00000373700.3
ALK	ENST00000618119.4	c.780C>T	p.Thr260Thr	splice_region_variant, synonymous_variant	9/28	5		ENSP00000482733.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neuroblastoma, susceptibility to, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 28, 2024

This sequence change affects codon 637 of the ALK mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the ALK protein. It affects a nucleotide within the consensus splice site. 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: 538266). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 23, 2022

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
CADD	Benign	15
DANN	Benign	0.87

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0040
dbscSNV1_RF	Benign	0.17
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: rs1553402750; hg19: chr2-29498269;