Genetic Variant NM_032601.4:c.419delA (chr2-71110081-CT-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The NM_032601.4(MCEE):c.419delA(p.Lys140ArgfsTer6) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000267 in 1,612,086 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000053 ( 1 hom., cov: 31)

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

MCEE
NM_032601.4 frameshift

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.23

Variant links:

Genes affected

MCEE (HGNC:16732): (methylmalonyl-CoA epimerase) The product of this gene catalyzes the interconversion of D- and L-methylmalonyl-CoA during the degradation of branched chain amino acids. odd chain-length fatty acids, and other metabolites. Mutations in this gene result in methylmalonyl-CoA epimerase deficiency, which is presented as mild to moderate methylmalonic aciduria. [provided by RefSeq, Jul 2008]

MCEE links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 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. Fraction of 0.211 CDS is truncated, and there are 0 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MCEE	NM_032601.4 link	c.419delA	p.Lys140ArgfsTer6	frameshift_variant	Exon 3 of 3	ENST00000244217.6	NP_115990.3	Q96PE7
MCEE	XM_005264613.3 link	c.257delA	p.Lys86ArgfsTer6	frameshift_variant	Exon 3 of 3		XP_005264670.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MCEE	ENST00000244217.6 link	c.419delA	p.Lys140ArgfsTer6	frameshift_variant	Exon 3 of 3	1	NM_032601.4	ENSP00000244217.5	Q96PE7
MCEE	ENST00000413592.5 link	c.125delA	p.Lys42ArgfsTer6	frameshift_variant	Exon 2 of 2	2		ENSP00000391140.1	H7BZS7
MCEE	ENST00000462609.2 link	n.365delA		non_coding_transcript_exon_variant	Exon 5 of 5	3

Frequencies

GnomAD3 genomes

AF:

0.0000527

AC:

AN:

151896

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000118

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000360

AC:

AN:

250236

Hom.:

AF XY:

0.0000296

AC XY:

AN XY:

135320

show subpopulations

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 SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000708

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000240

AC:

AN:

1460190

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

726446

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000297

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000527

AC:

AN:

151896

Hom.:

Cov.:

AF XY:

0.0000539

AC XY:

AN XY:

74190

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000453

EpiCase

AF:

0.00

EpiControl

AF:

0.0000594

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Oct 14, 2024

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MCEE c.419delA (p.Lys140ArgfsX6) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein. The variant allele was found at a frequency of 3.6e-05 in 250236 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.419delA has been reported in the literature in at least one individual affected with Parkinson disease, dementia, stroke and elevated levels of methylmalonic acid (e.g., Andrasson_2019). While the current variant may not result in NMD, it alters several amino acids located in the Vicinal oxygen chelate (VOC) domain. It is unclear what impact the variant will have on the function of this protein. These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 31146325). No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over