7-124825358-C-T

Variant names:

• chr7-124825358-C-T
• rs587777473
• NM_015450.3:c.1687-1G>A

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_015450.3(POT1):​c.1687-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000209 in 1,434,684 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POT1 NM_015450.3 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 5.31
• Publications: 6 publications found

Genes affected

POT1 (HGNC:17284): (protection of telomeres 1) This gene is a member of the telombin family and encodes a nuclear protein involved in telomere maintenance. Specifically, this protein functions as a member of a multi-protein complex that binds to the TTAGGG repeats of telomeres, regulating telomere length and protecting chromosome ends from illegitimate recombination, catastrophic chromosome instability, and abnormal chromosome segregation. Increased transcriptional expression of this gene is associated with stomach carcinogenesis and its progression. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jul 2008]

POT1 Gene-Disease associations (from GenCC):

• pulmonary fibrosis and/or bone marrow failure syndrome, telomere-related, 8

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• tumor predisposition syndrome 3

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• glioma susceptibility 9

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• thyroid gland carcinoma

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• cerebroretinal microangiopathy with calcifications and cysts 3

  Inheritance: AR Classification: LIMITED Submitted by: G2P, Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-124825358-C-T is Pathogenic according to our data. Variant chr7-124825358-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 139521.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POT1	NM_015450.3	c.1687-1G>A		splice_acceptor_variant, intron_variant	Intron 17 of 18	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.1687-1G>A		splice_acceptor_variant, intron_variant	Intron 17 of 18	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000420 AC: 1 AN: 238194 AF XY: 0.00000776

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000913

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000209 AC: 3 AN: 1434684 Hom.: 0 Cov.: 26 AF XY: 0.00000280 AC XY: 2 AN XY: 713970

⚠️ 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: 32536

American (AMR) AF: 0.00 AC: 0 AN: 42486

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25438

East Asian (EAS) AF: 0.00 AC: 0 AN: 39062

South Asian (SAS) AF: 0.00 AC: 0 AN: 81650

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52462

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5436

European-Non Finnish (NFE) AF: 0.00000274 AC: 3 AN: 1096348

Other (OTH) AF: 0.00 AC: 0 AN: 59266

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00131091), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tumor predisposition syndrome 3 Pathogenic:2

Oct 03, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 139521). Disruption of this splice site has been observed in individual(s) with melanoma (PMID: 24686849). This variant is present in population databases (rs587777473, gnomAD 0.0009%). This sequence change affects an acceptor splice site in intron 17 of the POT1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in POT1 are known to be pathogenic (PMID: 32155570). -

May 01, 2014

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided Uncertain:1

-

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.93	D
PhyloP100		5.3
GERP RS		5.1
Mutation Taster		=2/98	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.84
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.98		Position offset: -2
DS_AL_spliceai		0.99		Position offset: -1

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

Other links and lift over

dbSNP: rs587777473; hg19: chr7-124465412;