NM_005373.3:c.769C>T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP2PP3_ModeratePP5_Very_Strong

The NM_005373.3(MPL):c.769C>T(p.Arg257Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000112 in 1,614,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R257H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

MPL
NM_005373.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 2.86

Publications

23 publications found

Variant links:

Genes affected

MPL (HGNC:7217): (MPL proto-oncogene, thrombopoietin receptor) In 1990 an oncogene, v-mpl, was identified from the murine myeloproliferative leukemia virus that was capable of immortalizing bone marrow hematopoietic cells from different lineages. In 1992 the human homologue, named, c-mpl, was cloned. Sequence data revealed that c-mpl encoded a protein that was homologous with members of the hematopoietic receptor superfamily. Presence of anti-sense oligodeoxynucleotides of c-mpl inhibited megakaryocyte colony formation. The ligand for c-mpl, thrombopoietin, was cloned in 1994. Thrombopoietin was shown to be the major regulator of megakaryocytopoiesis and platelet formation. The protein encoded by the c-mpl gene, CD110, is a 635 amino acid transmembrane domain, with two extracellular cytokine receptor domains and two intracellular cytokine receptor box motifs . TPO-R deficient mice were severely thrombocytopenic, emphasizing the important role of CD110 and thrombopoietin in megakaryocyte and platelet formation. Upon binding of thrombopoietin CD110 is dimerized and the JAK family of non-receptor tyrosine kinases, as well as the STAT family, the MAPK family, the adaptor protein Shc and the receptors themselves become tyrosine phosphorylated. [provided by RefSeq, Jul 2008]

MPL Gene-Disease associations (from GenCC):

thrombocythemia 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen
congenital amegakaryocytic thrombocytopenia
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
congenital amegakaryocytic thrombocytopenia 1
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
familial thrombocytosis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
hereditary isolated aplastic anemia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

MPL links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 25 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 0.39478 (below the threshold of 3.09). Trascript score misZ: 1.6963 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary isolated aplastic anemia, congenital amegakaryocytic thrombocytopenia, thrombocythemia 2, congenital amegakaryocytic thrombocytopenia 1, familial thrombocytosis.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.868

PP5

Variant 1-43340042-C-T is Pathogenic according to our data. Variant chr1-43340042-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 14156.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MPL	NM_005373.3 link	c.769C>T	p.Arg257Cys	missense_variant	Exon 5 of 12	ENST00000372470.9	NP_005364.1	P40238-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MPL	ENST00000372470.9 link	c.769C>T	p.Arg257Cys	missense_variant	Exon 5 of 12	1	NM_005373.3	ENSP00000361548.3	P40238-1
MPL	ENST00000413998.7 link	c.748C>T	p.Arg250Cys	missense_variant	Exon 5 of 12	1		ENSP00000414004.3	Q5JUY5
MPL	ENST00000638732.1 link	n.769C>T		non_coding_transcript_exon_variant	Exon 5 of 10	1

Frequencies

GnomAD3 genomes

AF:

0.000105

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000169

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000415

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000103

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000598

AC:

AN:

250774

AF XY:

0.0000590

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000884

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000113

AC:

165

AN:

1461866

Hom.:

Cov.:

AF XY:

0.000110

AC XY:

AN XY:

727226

show subpopulations

African (AFR)

AF:

0.000149

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000580

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000135

AC:

150

AN:

1112004

Other (OTH)

AF:

0.0000662

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000105

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74360

show subpopulations

African (AFR)

AF:

0.000169

AC:

AN:

41460

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.000415

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000103

AC:

AN:

68050

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.494

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000154

Hom.:

Bravo

AF:

0.000117

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Congenital amegakaryocytic thrombocytopenia

Pathogenic:3

Jul 27, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: MPL c.769C>T (p.Arg257Cys) results in a non-conservative amino acid change located in the Fibronectin type III domain (IPR003961) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6e-05 in 250774 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in MPL causing Congenital Amegakaryocytic Thrombocytopenia (6e-05 vs 0.0024), allowing no conclusion about variant significance. c.769C>T has been reported in the literature in individuals affected with Congenital Amegakaryocytic Thrombocytopenia (example, VandenOudenrijn_2000, Lo_2018, Andres_2018). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in impaired signal transduction (Tijssen_2008). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Dept. of Cytogenetics, ICMR- National Institute of Immunohaematology

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

showed progression to aplastic anemia -

Congenital amegakaryocytic thrombocytopenia 1

Pathogenic:2

Mar 30, 2023

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

Jun 01, 2008

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Primary myelofibrosis;C3275998:Thrombocythemia 2;C5882667:Congenital amegakaryocytic thrombocytopenia 1

Pathogenic:1

Apr 30, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Pathogenic:1

Dec 28, 2017

Genetic Services Laboratory, University of Chicago

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Essential thrombocythemia;C1327915:Congenital amegakaryocytic thrombocytopenia

Pathogenic:1

Dec 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 257 of the MPL protein (p.Arg257Cys). This variant is present in population databases (rs121913611, gnomAD 0.009%). This missense change has been observed in individual(s) with congenital amegakaryocytic thrombocytopenia (PMID: 10971406, 28859041). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 14156). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MPL protein function. Experimental studies have shown that this missense change affects MPL function (PMID: 18422784, 20188141). This variant disrupts the p.Arg257 amino acid residue in MPL. Other variant(s) that disrupt this residue have been observed in individuals with MPL-related conditions (PMID: 16470591), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.56

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.93

D;.

Eigen

Pathogenic

0.76

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Uncertain

0.87

LIST_S2

Uncertain

0.91

D;D

M_CAP

Uncertain

0.23

MetaRNN

Pathogenic

0.87

D;D

MetaSVM

Uncertain

0.76

MutationAssessor

Uncertain

2.3

M;.

PhyloP100

2.9

PrimateAI

Uncertain

0.60

PROVEAN

Pathogenic

-5.3

D;.

REVEL

Pathogenic

0.80

Sift

Uncertain

0.0020

D;.

Sift4G

Pathogenic

0.0

D;.

Polyphen

1.0

D;.

Vest4

0.63

MVP

0.97

MPC

0.88

ClinPred

0.78

GERP RS

6.0

Varity_R

0.49

gMVP

0.74

Mutation Taster

=8/92

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over