NM_005373.3:c.19T>C

Variant names:

• chr1-43337867-T-C
• NM_005373.3:c.19T>C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005373.3(MPL):​c.19T>C​(p.Phe7Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MPL NM_005373.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.38

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1042096).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MPL	NM_005373.3	c.19T>C	p.Phe7Leu	missense_variant	Exon 1 of 12	ENST00000372470.9	NP_005364.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MPL	ENST00000372470.9	c.19T>C	p.Phe7Leu	missense_variant	Exon 1 of 12	1	NM_005373.3	ENSP00000361548.3
MPL	ENST00000413998.7	c.19T>C	p.Phe7Leu	missense_variant	Exon 1 of 12	1		ENSP00000414004.3
MPL	ENST00000638732.1	n.19T>C		non_coding_transcript_exon_variant	Exon 1 of 10	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Essential thrombocythemia;C1327915:Congenital amegakaryocytic thrombocytopenia Uncertain:1

Jan 11, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 7 of the MPL protein (p.Phe7Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MPL-related conditions. 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) indicates that this missense variant is not expected to disrupt MPL protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.53
CADD	Benign	16
DANN	Benign	0.74
DEOGEN2	Benign	0.22	T;.
Eigen	Benign	-0.65
Eigen_PC	Benign	-0.42
FATHMM_MKL	Benign	0.48	N
LIST_S2	Benign	0.58	T;T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.10	T;T
MetaSVM	Benign	-0.89	T
MutationAssessor	Benign	0.41	N;.
PrimateAI	Benign	0.40	T
PROVEAN	Benign	0.11	N;N
REVEL	Benign	0.15
Sift	Benign	0.53	T;T
Sift4G	Benign	1.0	T;T
Polyphen		0.0	B;B
Vest4		0.14
MutPred		0.41		Gain of disorder (P = 0.0516);Gain of disorder (P = 0.0516);
MVP		0.66
MPC		0.22
ClinPred		0.060	T
GERP RS		2.6
Varity_R		0.072
gMVP		0.32

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-43803538;