1-43340495-G-C

Variant names:

• chr1-43340495-G-C
• rs149265851
• NM_005373.3:c.962G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_005373.3(MPL):​c.962G>C​(p.Arg321Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,886 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. R321Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MPL NM_005373.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.363
• Publications: 6 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]

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MPL	NM_005373.3	c.962G>C	p.Arg321Pro	missense_variant	Exon 6 of 12	ENST00000372470.9	NP_005364.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MPL	ENST00000372470.9	c.962G>C	p.Arg321Pro	missense_variant	Exon 6 of 12	1	NM_005373.3	ENSP00000361548.3
MPL	ENST00000413998.7	c.941G>C	p.Arg314Pro	missense_variant	Exon 6 of 12	1		ENSP00000414004.3
MPL	ENST00000638732.1	n.962G>C		non_coding_transcript_exon_variant	Exon 6 of 10	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251482 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000992

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461886 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

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

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

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112008

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

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000254 Hom.: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.070	D
BayesDel_noAF	Benign	-0.14
CADD	Benign	11
DANN	Benign	0.95
DEOGEN2	Benign	0.38	T;.
Eigen	Benign	-0.58
Eigen_PC	Benign	-0.68
FATHMM_MKL	Benign	0.13	N
LIST_S2	Benign	0.73	T;T
M_CAP	Benign	0.047	D
MetaRNN	Uncertain	0.47	T;T
MetaSVM	Benign	-0.68	T
MutationAssessor	Uncertain	2.2	M;.
PhyloP100		-0.36
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-1.3	N;.
REVEL	Uncertain	0.57
Sift	Uncertain	0.014	D;.
Sift4G	Uncertain	0.017	D;.
Polyphen		0.49	P;.
Vest4		0.58
MutPred		0.74		Loss of sheet (P = 0.0228);.;
MVP		0.65
MPC		0.37
ClinPred		0.38	T
GERP RS		0.33
Varity_R		0.19
gMVP		0.64
Mutation Taster		=82/18	polymorphism

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

Other links and lift over

dbSNP: rs149265851; hg19: chr1-43806166;