rs587778514

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_005373.3(MPL):c.235_236delCT(p.Leu79GlufsTer84) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,614,080 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L79L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

MPL
NM_005373.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8O:1

Conservation

PhyloP100: 2.74

Publications

4 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 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 1-43338563-CCT-C is Pathogenic according to our data. Variant chr1-43338563-CCT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 134822.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.235_236delCT	p.Leu79GlufsTer84	frameshift_variant	Exon 3 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.235_236delCT	p.Leu79GlufsTer84	frameshift_variant	Exon 3 of 12	1	NM_005373.3	ENSP00000361548.3	P40238-1
MPL	ENST00000413998.7 link	c.214_215delCT	p.Leu72GlufsTer84	frameshift_variant	Exon 3 of 12	1		ENSP00000414004.3	Q5JUY5
MPL	ENST00000638732.1 link	n.235_236delCT		non_coding_transcript_exon_variant	Exon 3 of 10	1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000517

AC:

AN:

251394

AF XY:

0.0000589

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.000109

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000792

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000233

AC:

AN:

1461892

Hom.:

AF XY:

0.0000275

AC XY:

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000180

AC:

AN:

1112010

Other (OTH)

AF:

0.0000993

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

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:

0.0000460

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74342

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41442

American (AMR)

AF:

0.0000654

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000385

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.518

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:

0.0000434

Hom.:

Bravo

AF:

0.0000227

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000178

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Congenital amegakaryocytic thrombocytopenia

Pathogenic:4

Apr 18, 2017

Genetic Services Laboratory, University of Chicago

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Neuberg Centre For Genomic Medicine, NCGM

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The MPL c.235_236del (p.Leu79GlufsTer84) variant has been reported in homozygous state in individuals affected with Amegakaryocytic Thrombocytopenia, Congenital (Ballmaier M et al.). Experimental studies have shown that this frameshift predicted to result in a complete absence of functional c-Mpl protein. This variant has also been reported to lead to a complete loss of a functional TPO receptor c-Mpl (Ballmaier M et al.). This variant has been submitted with the allele frequency 0.005% in the gnomAD and novel in 1000 genome database. It has been submitted to ClinVar as Pathogenic. This variant causes a frameshift starting with codon Leucine 79, changes this amino acid to Glutamic Acid residue, and creates a premature Stop codon at position 84 of the new reading frame, denoted p.Leu79GlufsTer84. Loss-of-function variants in MPL are known to be pathogenic (Gurney AL et al.) For these reasons, this variant has been classified as Pathogenic. -

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 12, 2017

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

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: The MPL c.235_236delCT (p.Leu79Glufs) variant results in a premature termination codon, predicted to cause a truncated or absent MPL protein due to nonsense mediated decay, which are commonly known mechanisms for disease. One in silico tool predicts a damaging outcome for this variant. This variant was found in 6/121376 control chromosomes at a frequency of 0.0000494, which does not exceed the estimated maximal expected allele frequency of a pathogenic MPL variant (0.002357). The variant has been reported in affected individuals in the literature in the homozygous and compound heterozygous state. Taken together, this variant is classified as pathogenic. -

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

Pathogenic:1

May 09, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Congenital amegakaryocytic thrombocytopenia 1

Pathogenic:1

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

PM2_Supporting+PVS1+PM3_Strong -

not provided

Pathogenic:1

Sep 04, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Published functional studies demonstrate a damaging effect of no protein expression (Gandhi et al., 2005); This variant is associated with the following publications: (PMID: 19388932, 17666371, 21228398, 16470591, 19302922, 31350202, 29625052, 34426522, 31589614, 11133753, 16219544) -

Essential thrombocythemia;C1327915:Congenital amegakaryocytic thrombocytopenia

Pathogenic:1

Feb 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Leu79Glufs*84) in the MPL gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MPL are known to be pathogenic (PMID: 8073287, 11133753). This variant is present in population databases (rs587778514, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with congenital amegakaryocytic thrombocytopenia (PMID: 11133753, 17666371). This variant is also known as del235/236. ClinVar contains an entry for this variant (Variation ID: 134822). For these reasons, this variant has been classified as Pathogenic. -

not specified

Other:1

Sep 19, 2013

ITMI

Significance:not provided

Review Status:no classification provided

Collection Method:reference population

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

2.7

Mutation Taster

=10/190

disease causing (ClinVar)

(source)

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

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