6-49448840-G-C

Variant names:

• chr6-49448840-G-C
• rs887126161
• NM_000255.4:c.1420C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_000255.4(MMUT):​c.1420C>G​(p.Arg474Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,044 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R474P) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MMUT NM_000255.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.52
• Publications: 0 publications found

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]

MMUT Gene-Disease associations (from GenCC):

• methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
• vitamin B12-unresponsive methylmalonic acidemia type mut-

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• vitamin B12-unresponsive methylmalonic acidemia type mut0

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-49448839-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1363055.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 150 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 0.22855 (below the threshold of 3.09). Trascript score misZ: 1.0842 (below the threshold of 3.09). GenCC associations: The gene is linked to vitamin B12-unresponsive methylmalonic acidemia type mut-, methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency, vitamin B12-unresponsive methylmalonic acidemia type mut0.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.885

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMUT	NM_000255.4	c.1420C>G	p.Arg474Gly	missense_variant	Exon 7 of 13	ENST00000274813.4	NP_000246.2
MMUT	XM_005249143.4	c.1420C>G	p.Arg474Gly	missense_variant	Exon 7 of 13		XP_005249200.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMUT	ENST00000274813.4	c.1420C>G	p.Arg474Gly	missense_variant	Exon 7 of 13	1	NM_000255.4	ENSP00000274813.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461044 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726872

African (AFR) AF: 0.00 AC: 0 AN: 33432

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39626

South Asian (SAS) AF: 0.00 AC: 0 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111408

Other (OTH) AF: 0.0000166 AC: 1 AN: 60358

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.29
CADD	Uncertain	26
DANN	Uncertain	1.0
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	1.1	D
PhyloP100		6.5
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-4.6	D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.015	D
Sift4G	Uncertain	0.055	T
Vest4		0.88
ClinPred		0.99	D
GERP RS		5.1
gMVP		0.91
Mutation Taster		=29/71	disease causing

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

Other links and lift over

dbSNP: rs887126161; hg19: chr6-49416553;