chr9-21815518-A-G

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_002451.4(MTAP):c.119A>G(p.Lys40Arg) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000312 in 1,601,404 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predicting alterations to normal splicing. 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. K40Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

MTAP
NM_002451.4 missense, splice_region

Scores

Splicing: ADA: 1.000

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.33

Publications

1 publications found

Variant links:

Genes affected

MTAP (HGNC:7413): (methylthioadenosine phosphorylase) This gene encodes an enzyme that plays a major role in polyamine metabolism and is important for the salvage pathway of both adenine and methionine. The encoded enzyme is deficient in many cancers. Multiple alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Sep 2021]

MTAP Gene-Disease associations (from GenCC):

diaphyseal medullary stenosis-bone malignancy syndrome
Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Genomics England PanelApp, G2P, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen

MTAP links:

ENSG00000264545 (HGNC:):

ENSG00000264545 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTAP	NM_002451.4 link	c.119A>G	p.Lys40Arg	missense_variant, splice_region_variant	Exon 2 of 8	ENST00000644715.2	NP_002442.2	Q13126-1A0A384ME80

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTAP	ENST00000644715.2 link	c.119A>G	p.Lys40Arg	missense_variant, splice_region_variant	Exon 2 of 8		NM_002451.4	ENSP00000494373.1		Q13126-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151864

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000276

AC:

AN:

1449540

Hom.:

Cov.:

AF XY:

0.00000416

AC XY:

AN XY:

721680

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33182

American (AMR)

AF:

0.00

AC:

AN:

44604

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26058

East Asian (EAS)

AF:

0.00

AC:

AN:

39600

South Asian (SAS)

AF:

0.00

AC:

AN:

85274

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53374

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5624

European-Non Finnish (NFE)

AF:

0.00000182

AC:

AN:

1101894

Other (OTH)

AF:

0.0000167

AC:

AN:

59930

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151864

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74166

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41330

American (AMR)

AF:

0.00

AC:

AN:

15250

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10512

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67974

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Diaphyseal medullary stenosis-bone malignancy syndrome

Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.55

D;D;D;.

Eigen

Benign

0.087

Eigen_PC

Uncertain

0.27

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

.;D;D;D

M_CAP

Benign

0.083

MetaRNN

Uncertain

0.61

D;D;D;D

MetaSVM

Uncertain

-0.19

MutationAssessor

Benign

1.9

L;.;L;L

PhyloP100

8.3

PrimateAI

Pathogenic

0.82

PROVEAN

Benign

-2.1

N;.;.;.

REVEL

Uncertain

0.31

Sift

Benign

0.14

T;.;.;.

Sift4G

Benign

0.17

T;T;.;T

Polyphen

0.041

B;B;B;.

Vest4

0.67

MutPred

0.36

.;Loss of methylation at K57 (P = 0.0179);.;.;

MVP

0.89

MPC

0.36

ClinPred

0.94

GERP RS

5.3

Varity_R

0.69

gMVP

0.73

Mutation Taster

=3/97

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

1.0

SpliceAI score (max)

0.69

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.69

Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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chr9-21815518-A-G

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over