rs864309724
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong
The NM_004991.4(MECOM):c.2812C>T(p.Arg938Trp) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. R938Q) has been classified as Pathogenic.
Frequency
Consequence
NM_004991.4 missense
Scores
Clinical Significance
Conservation
Publications
- MECOM-associated syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- radioulnar synostosis with amegakaryocytic thrombocytopenia 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
- radio-ulnar synostosis-amegakaryocytic thrombocytopenia syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MECOM | NM_004991.4 | c.2812C>T | p.Arg938Trp | missense_variant | Exon 12 of 17 | ENST00000651503.2 | NP_004982.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MECOM | ENST00000651503.2 | c.2812C>T | p.Arg938Trp | missense_variant | Exon 12 of 17 | NM_004991.4 | ENSP00000498411.1 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0AN: 1456170Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0AN XY: 724312
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Radioulnar synostosis with amegakaryocytic thrombocytopenia 2 Pathogenic:2
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This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -
not provided Pathogenic:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 29519864, 20091385, 26581901, 29540340, 29097497, 29200407, 32098966, Pronama2021[Review], 35219593, 35470277, 36515795) -
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 750 of the MECOM protein (p.Arg750Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of radioulnar synostosis with amegakaryocytic thrombocytopenia (PMID: 26581901, 29146883, 29200407, 29519864). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 218953). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects MECOM function (PMID: 26581901, 35219593). For these reasons, this variant has been classified as Pathogenic. -
MECOM-related disorder Pathogenic:1
The MECOM c.2248C>T variant is predicted to result in the amino acid substitution p.Arg750Trp. This variant has been reported as a recurrent de novo variant in individuals with radioulnar synostosis with amegakaryocytic thrombocytopenia-2 (Niihori et al. 2015. PubMed ID: 26581901; Germeshausen et al. 2018. PubMed ID: 29540340; Lord et al. 2018. PubMed ID: 29200407; Walne et al. 2018. PubMed ID: 29519864). This variant has not been reported in a large population database, indicating this variant is rare. Given the evidence, we interpret c.2248C>T (p.Arg750Trp) as pathogenic. -
MECOM-associated syndrome Pathogenic:1
The p.Arg938Trp (also known as p.Arg750Trp) variant in MECOM has been reported in at least 7 individuals with MECOM-associated syndrome (PMID: 29540340, 29200407, 295198642, 26581901, 29519864), and was absent from large population studies. This variant was found to be de novo in at least 5 individuals with and without confirmed paternity and maternity (PMID: 29540340, 29200407, 295198642). This variant has also been reported in ClinVar (VCV000218953.7) and has been interpreted as pathogenic by Baylor Genetics, GeneDx, Labcorp Genetics, OMIM and PreventionGenetics. In vitro functional studies provide some evidence that the p.Arg938Trp variant may slightly impact protein function (PMID: 26581901). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. The p.Arg938Trp variant is located in a region of MECOM that is essential to protein folding and stability, suggesting that this variant is in a functional domain and slightly supports pathogenicity (PMID: 35219593). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal dominant MECOM-associated syndrome. ACMG/AMP Criteria applied: PS2_moderate, PM1_supporting, PM2_supporting, PS3_supporting, PS4_supporting (Richards 2015). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at