rs770402221

Variant names:

• chr1-43352607-CCT-C
• rs770402221
• NM_005373.3:c.1744_1745delCT

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Strong PP5

The NM_005373.3(MPL):​c.1744_1745delCT​(p.Leu582ValfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: MPL NM_005373.3 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 2.05
• Publications: 0 publications found

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]

CDC20-DT (HGNC:55681): (CDC20 divergent transcript)

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.
• PP5: Variant 1-43352607-CCT-C is Pathogenic according to our data. Variant chr1-43352607-CCT-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 458369.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005373.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPL	NM_005373.3	MANE Select	c.1744_1745delCT	p.Leu582ValfsTer30	frameshift	Exon 12 of 12	NP_005364.1	P40238-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPL	ENST00000372470.9	TSL:1 MANE Select	c.1744_1745delCT	p.Leu582ValfsTer30	frameshift	Exon 12 of 12	ENSP00000361548.3	P40238-1
	MPL	ENST00000413998.7	TSL:1	c.1723_1724delCT	p.Leu575ValfsTer30	frameshift	Exon 12 of 12	ENSP00000414004.3	Q5JUY5
	MPL	ENST00000967221.1		c.1759_1760delCT	p.Leu587ValfsTer30	frameshift	Exon 12 of 12	ENSP00000637280.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251472 AF XY: 0.0000221

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: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461894 Hom.: 0 AF XY: 0.00000963 AC XY: 7 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
1	-	-	Congenital amegakaryocytic thrombocytopenia (1)
-	1	-	Essential thrombocythemia;C1327915:Congenital amegakaryocytic thrombocytopenia (1)
1	-	-	Primary myelofibrosis;C3275998:Thrombocythemia 2;C5882667:Congenital amegakaryocytic thrombocytopenia 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.1
Mutation Taster		=31/169	disease causing

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: rs770402221; hg19: chr1-43818278;