9-5073770-G-C

Variant names:

• chr9-5073770-G-C
• rs77375493
• NM_004972.4:c.1849G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PM5

The NM_004972.4(JAK2):​c.1849G>C​(p.Val617Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,454,466 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V617I) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: JAK2 NM_004972.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.55
• Publications: 1 publications found

Genes affected

JAK2 (HGNC:6192): (Janus kinase 2) This gene encodes a non-receptor tyrosine kinase that plays a central role in cytokine and growth factor signalling. The primary isoform of this protein has an N-terminal FERM domain that is required for erythropoietin receptor association, an SH2 domain that binds STAT transcription factors, a pseudokinase domain and a C-terminal tyrosine kinase domain. Cytokine binding induces autophosphorylation and activation of this kinase. This kinase then recruits and phosphorylates signal transducer and activator of transcription (STAT) proteins. Growth factors like TGF-beta 1 also induce phosphorylation and activation of this kinase and translocation of downstream STAT proteins to the nucleus where they influence gene transcription. Mutations in this gene are associated with numerous inflammatory diseases and malignancies. This gene is a downstream target of the pleiotropic cytokine IL6 that is produced by B cells, T cells, dendritic cells and macrophages to produce an immune response or inflammation. Disregulation of the IL6/JAK2/STAT3 signalling pathways produces increased cellular proliferation and myeloproliferative neoplasms of hematopoietic stem cells. A nonsynonymous mutation in the pseudokinase domain of this gene disrupts the domains inhibitory effect and results in constitutive tyrosine phosphorylation activity and hypersensitivity to cytokine signalling. This gene and the IL6/JAK2/STAT3 signalling pathway is a therapeutic target for the treatment of excessive inflammatory responses to viral infections. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2020]

INSL6 (HGNC:6089): (insulin like 6) The protein encoded by this gene contains a classical signature of the insulin superfamily and is significantly similar to relaxin and relaxin-like factor. This gene is preferentially expressed in testis. Its expression in testis is restricted to interstitial cells surrounding seminiferous tubules, which suggests a role in sperm development and fertilization. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-5073770-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 29763.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004972.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	JAK2	NM_004972.4	MANE Select	c.1849G>C	p.Val617Leu	missense	Exon 14 of 25	NP_004963.1
	JAK2	NM_001322194.2		c.1849G>C	p.Val617Leu	missense	Exon 14 of 25	NP_001309123.1
	JAK2	NM_001322195.2		c.1849G>C	p.Val617Leu	missense	Exon 13 of 24	NP_001309124.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	JAK2	ENST00000381652.4	TSL:1 MANE Select	c.1849G>C	p.Val617Leu	missense	Exon 14 of 25	ENSP00000371067.4
	JAK2	ENST00000870320.1		c.1849G>C	p.Val617Leu	missense	Exon 14 of 25	ENSP00000540379.1
	JAK2	ENST00000870321.1		c.1849G>C	p.Val617Leu	missense	Exon 14 of 25	ENSP00000540380.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1454466 Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0 AN XY: 723944

⚠️ 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: 33290

American (AMR) AF: 0.00 AC: 0 AN: 44662

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26036

East Asian (EAS) AF: 0.00 AC: 0 AN: 39596

South Asian (SAS) AF: 0.00 AC: 0 AN: 86006

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52988

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5748

European-Non Finnish (NFE) AF: 9.04e-7 AC: 1 AN: 1105994

Other (OTH) AF: 0.00 AC: 0 AN: 60146

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.72	D
Eigen	Benign	0.17
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.091	D
MetaRNN	Uncertain	0.74	D
MetaSVM	Benign	-0.41	T
MutationAssessor	Benign	0.98	L
PhyloP100		9.5
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-1.9	N
REVEL	Uncertain	0.60
Sift	Benign	0.051	T
Sift4G	Benign	0.091	T
Polyphen		0.083	B
Vest4		0.73
MutPred		0.58		Loss of sheet (P = 0.1398)
MVP		0.96
MPC		0.33
ClinPred		0.88	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.62
gMVP		0.52
Mutation Taster		=68/32	polymorphism

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

Other links and lift over

dbSNP: rs77375493; hg19: chr9-5073770;