Genetic Information

Gene & Transcript Details

Gene
JAK2
Transcript
NM_004972.3 MANE Select
Total Exons
Reference Sequence
NC_000009.11
Alternative Transcripts
IDStatusDetails
NM_004972.4 MANE Select 7023 nt | 468–3866
NM_004972.2 Alternative 5097 nt | 495–3893
NM_004972.3 RefSeq Select 5285 nt | 495–3893

Variant Details

HGVS Notation
NM_004972.3:c.1613_1616delinsT
Protein Change
H538_K539delinsL
Location
Exon 12 (Exon 12 of )
12
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.0 in 100,000
Extremely Rare
ACMG Criteria Applied PM2
This variant is absent or extremely rare in population databases (PM2 criteria applies).

ClinVar

Open
Classification
Unknown
0 publications
Clinical Statement

""

COSMIC Somatic Evidence

Open
COSMIC ID
COSM27149
Recurrence
11 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC Preview
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Functional Impact & Domains

Functional Domain

Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain.
Related Variants in This Domain
No evidence of other pathogenic variants at this position in gene JAK2.

Functional Studies & Therapeutic Relevance

Functional Summary

The JAK2 H538_K539delinsL variant has been functionally characterized as activating. Expression of this mutation in immortalized mouse progenitor B cells demonstrated increased protein and downstream pathway activation, as well as cytokine-independent growth, indicating a gain-of-function effect.

Database Previews
OncoKB
OncoKB Preview
JAX-CKB
JAX-CKB Preview

Click on previews to view full database entries. External databases may require institutional access.

Computational Analysis

Pathogenicity Predictions

SpliceAI
Predictor Consensus
Unknown
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 -31 bp
- Donor Loss (DL) 0.0 28 bp
+ Acceptor Gain (AG) 0.0 -99 bp
+ Donor Gain (DG) 0.0 -8 bp
High impact (≥0.5) Medium impact (0.2-0.49) Low impact (<0.2)

VCEP Guidelines

Applied ACMG/AMP Criteria (VCEP Specific)

Filter Criteria:
PVS1

PVS1 (Not Applied)

According to standard ACMG guidelines, the rule for PVS1 is: 'Null variant in a gene where loss of function (LoF) is a known mechanism of disease (e.g., nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single exon deletion in a LoF gene)'. The evidence for this variant shows: H538_K539delinsL is an in-frame deletion/insertion altering amino acids but does not introduce a premature stop codon or disrupt canonical splice sites. Therefore, this criterion is not applied at Not Applied because the variant is not a null LoF variant.

PS1

PS1 (Not Applied)

According to standard ACMG guidelines, the rule for PS1 is: 'Same amino acid change as a known pathogenic variant but different nucleotide change'. The evidence for this variant shows: no other variant producing H538_K539delinsL has been reported as pathogenic. Therefore, this criterion is not applied at Not Applied because there is no known identical amino acid change in a different nucleotide context.

PS2

PS2 (Not Applied)

According to standard ACMG guidelines, the rule for PS2 is: 'De novo (both maternity and paternity confirmed) in a patient with the disease and no family history'. The evidence for this variant shows: no information on de novo occurrence or parental testing. Therefore, this criterion is not applied at Not Applied due to lack of de novo data.

PS3

PS3 (Strong)

According to standard ACMG guidelines, the rule for PS3 is: 'Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product'. The evidence for this variant shows: functional characterization demonstrated that H538_K539delinsL is activating, with increased downstream pathway activation and cytokine-independent growth in mouse progenitor B cells. Therefore, this criterion is applied at Strong strength because robust functional studies support a damaging gain-of-function effect.

PS4

PS4 (Not Applied)

According to standard ACMG guidelines, the rule for PS4 is: 'Prevalence in affected individuals significantly increased compared with controls'. The evidence for this variant shows: no case-control or prevalence data. Therefore, this criterion is not applied at Not Applied due to lack of prevalence data.

PM1

PM1 (Not Applied)

According to standard ACMG guidelines, the rule for PM1 is: 'Located in a mutational hot spot or well-established functional domain without benign variation'. The evidence for this variant shows: no specific information on a mutational hotspot or absence of benign variation at this site. Therefore, this criterion is not applied at Not Applied.

PM2

PM2 (Moderate)

According to standard ACMG guidelines, the rule for PM2 is: 'Absent from controls (or at extremely low frequency if recessive)'. The evidence for this variant shows: it is not found in gnomAD or other population databases (MAF=0%). Therefore, this criterion is applied at Moderate strength because the variant is absent from population controls.

PM3

PM3 (Not Applied)

According to standard ACMG guidelines, the rule for PM3 is: 'Detected in trans with a pathogenic variant for recessive disorders'. The evidence for this variant shows: JAK2-associated disease is dominant and no trans-phase data. Therefore, this criterion is not applied at Not Applied.

PM4

PM4 (Moderate)

According to standard ACMG guidelines, the rule for PM4 is: 'Protein length changes due to in-frame deletions/insertions or stop-loss variants'. The evidence for this variant shows: H538_K539delinsL results in net deletion of two amino acids and insertion of one, altering protein length. Therefore, this criterion is applied at Moderate strength because the variant causes a protein length change.

PM5

PM5 (Not Applied)

According to standard ACMG guidelines, the rule for PM5 is: 'Novel missense change at an amino acid residue where a different pathogenic missense change has been seen'. The evidence for this variant shows: it is an in-frame indel, not a novel missense change. Therefore, this criterion is not applied at Not Applied.

PM6

PM6 (Not Applied)

According to standard ACMG guidelines, the rule for PM6 is: 'Assumed de novo, but without confirmation of paternity and maternity'. The evidence for this variant shows: no de novo or parental data. Therefore, this criterion is not applied at Not Applied.

PP1

PP1 (Not Applied)

According to standard ACMG guidelines, the rule for PP1 is: 'Co-segregation with disease in multiple affected family members'. The evidence for this variant shows: no family segregation data. Therefore, this criterion is not applied at Not Applied.

PP2

PP2 (Not Applied)

According to standard ACMG guidelines, the rule for PP2 is: 'Missense variant in a gene with a low rate of benign missense variation and where missense variants are a common mechanism of disease'. The evidence for this variant shows: it is an in-frame indel, not a missense variant. Therefore, this criterion is not applied at Not Applied.

PP3

PP3 (Not Applied)

According to standard ACMG guidelines, the rule for PP3 is: 'Multiple lines of computational evidence support a deleterious effect on the gene/product'. The evidence for this variant shows: in silico predictions are benign and SpliceAI score is 0. Therefore, this criterion is not applied at Not Applied because computational evidence does not support a deleterious effect.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: 'Patient's phenotype or family history highly specific for a disease with a single genetic etiology'. The evidence for this variant shows: no detailed phenotype or family history provided. Therefore, this criterion is not applied at Not Applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, the rule for PP5 is: 'Reputable source reports variant as pathogenic, but without accessible evidence'. The evidence for this variant shows: no such reports in ClinVar or other databases. Therefore, this criterion is not applied at Not Applied.

BA1

BA1 (Not Applied)

According to standard ACMG guidelines, the rule for BA1 is: 'Allele frequency is too high for disorder'. The evidence for this variant shows: absent from populations (MAF=0%). Therefore, this criterion is not applied at Not Applied.

BS1

BS1 (Not Applied)

According to standard ACMG guidelines, the rule for BS1 is: 'Allele frequency is greater than expected for disorder'. The evidence for this variant shows: absent from population databases. Therefore, this criterion is not applied at Not Applied.

BS2

BS2 (Not Applied)

According to standard ACMG guidelines, the rule for BS2 is: 'Observed in healthy individuals with full penetrance expected'. The evidence for this variant shows: no data from healthy cohorts. Therefore, this criterion is not applied at Not Applied.

BS3

BS3 (Not Applied)

According to standard ACMG guidelines, the rule for BS3 is: 'Well-established functional studies show no damaging effect'. The evidence for this variant shows: functional studies indicate a damaging gain-of-function effect. Therefore, this criterion is not applied at Not Applied.

BS4

BS4 (Not Applied)

According to standard ACMG guidelines, the rule for BS4 is: 'Lack of segregation in affected family members'. The evidence for this variant shows: no family segregation data. Therefore, this criterion is not applied at Not Applied.

BP1

BP1 (Not Applied)

According to standard ACMG guidelines, the rule for BP1 is: 'Missense variant in a gene where only LoF causes disease'. The evidence for this variant shows: it is an in-frame indel in JAK2, not a missense variant. Therefore, this criterion is not applied at Not Applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, the rule for BP2 is: 'Observed in trans with a pathogenic variant for dominant disorders or in cis with a pathogenic variant'. The evidence for this variant shows: no data on co-occurrence with other variants. Therefore, this criterion is not applied at Not Applied.

BP3

BP3 (Not Applied)

According to standard ACMG guidelines, the rule for BP3 is: 'In-frame deletions/insertions in a repetitive region without known function'. The evidence for this variant shows: the altered region is not a repetitive sequence. Therefore, this criterion is not applied at Not Applied.

BP4

BP4 (Supporting)

According to standard ACMG guidelines, the rule for BP4 is: 'Multiple lines of computational evidence suggest no impact on gene or gene product'. The evidence for this variant shows: computational predictions are benign and SpliceAI predicts no splicing impact. Therefore, this criterion is applied at Supporting strength because in silico evidence indicates no deleterious effect.

BP5

BP5 (Not Applied)

According to standard ACMG guidelines, the rule for BP5 is: 'Variant found in a case with an alternate molecular basis for disease'. The evidence for this variant shows: no such alternate molecular findings. Therefore, this criterion is not applied at Not Applied.

BP6

BP6 (Not Applied)

According to standard ACMG guidelines, the rule for BP6 is: 'Reputable source reports variant as benign, but without accessible evidence'. The evidence for this variant shows: no such reports. Therefore, this criterion is not applied at Not Applied.

BP7

BP7 (Not Applied)

According to standard ACMG guidelines, the rule for BP7 is: 'Synonymous variant with no predicted impact on splicing'. The evidence for this variant shows: it is not synonymous. Therefore, this criterion is not applied at Not Applied.