rs757000253

Variant names:

• chr6-49457977-T-A
• rs757000253
• NM_000255.4:c.467A>T

Your query was ambiguous. Multiple possible variants found:

• chr6-49457977-T-A
• chr6-49457977-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PM5 PP3_Strong PP5

The NM_000255.4(MMUT):​c.467A>T​(p.Asp156Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 11/19 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D156N) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MMUT NM_000255.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.56

Genes affected

MMUT (HGNC:7526): (methylmalonyl-CoA mutase) This gene encodes the mitochondrial enzyme methylmalonyl Coenzyme A mutase. In humans, the product of this gene is a vitamin B12-dependent enzyme which catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA, while in other species this enzyme may have different functions. Mutations in this gene may lead to various types of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.965
• PP5: Variant 6-49457977-T-A is Pathogenic according to our data. Variant chr6-49457977-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 222913.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMUT	NM_000255.4	c.467A>T	p.Asp156Val	missense_variant	Exon 3 of 13	ENST00000274813.4	NP_000246.2
MMUT	XM_005249143.4	c.467A>T	p.Asp156Val	missense_variant	Exon 3 of 13		XP_005249200.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMUT	ENST00000274813.4	c.467A>T	p.Asp156Val	missense_variant	Exon 3 of 13	1	NM_000255.4	ENSP00000274813.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1456768 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 724930

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency Pathogenic:1

-

University Children's Hospital, University of Zurich

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified Uncertain:1

Jan 08, 2025

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: MUT c.467A>T (p.Asp156Val) results in a non-conservative amino acid change located in the cobalamin (vitamin B12)-dependent enzyme domain (IPR016176) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The frequency data for this variant in gnomAD is considered unreliable, as metrics indicate poor data quality at this position. c.467A>T has been reported in the literature in individuals affected with Methylmalonic Acidemia (e.g., Forny_2016, Hu_2022, Liang_2023, Liang_2021, Ling_2024, Yu_2021). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 27167370, 35361390, 37316190, 33413471, 39075538, 34668645). ClinVar contains an entry for this variant (Variation ID: 222913). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.77	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-9.0	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.92
MutPred		0.79		Loss of disorder (P = 0.0421);
MVP		0.99
MPC		0.58
ClinPred		1.0	D
GERP RS		5.5
gMVP		0.96

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

LitVar

Other links and lift over

dbSNP: rs757000253; hg19: chr6-49425690;