6-49459144-C-T

Variant names:

• chr6-49459144-C-T
• rs483352778
• NM_000255.4:c.323G>A

Variant summary

Our verdict is Pathogenic. The variant received 23 ACMG points: 23P and 0B. PS3 PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000255.4(MMUT):​c.323G>A​(p.Arg108His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,614,108 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000919780: "This variant has been reported in multiple affected individuals mostly as compound heterozygotes and the patients' fibroblasts presented with a marked decrease in MCM enzyme activity (Acquaviva_2001 and Lempp_2007)."". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R108C) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: MMUT NM_000255.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9 O:1
• Conservation: PhyloP100: 7.50
• Publications: 30 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: Labcorp Genetics (formerly Invitae), ClinGen, 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: Pathogenic. The variant received 23 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000919780: "This variant has been reported in multiple affected individuals mostly as compound heterozygotes and the patients' fibroblasts presented with a marked decrease in MCM enzyme activity (Acquaviva_2001 and Lempp_2007)."
• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_000255.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-49459145-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 1887.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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 methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency, vitamin B12-unresponsive methylmalonic acidemia type mut-, vitamin B12-unresponsive methylmalonic acidemia type mut0.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 6-49459144-C-T is Pathogenic according to our data. Variant chr6-49459144-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 100707.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000255.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMUT	NM_000255.4	MANE Select	c.323G>A	p.Arg108His	missense	Exon 2 of 13	NP_000246.2	P22033

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMUT	ENST00000274813.4	TSL:1 MANE Select	c.323G>A	p.Arg108His	missense	Exon 2 of 13	ENSP00000274813.3	P22033
	MMUT	ENST00000878060.1		c.323G>A	p.Arg108His	missense	Exon 2 of 13	ENSP00000548119.1
	MMUT	ENST00000878062.1		c.323G>A	p.Arg108His	missense	Exon 2 of 13	ENSP00000548121.1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000199 AC: 5 AN: 251292 AF XY: 0.0000221

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000198 AC: 29 AN: 1461844 Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13 AN XY: 727226

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.0000504 AC: 2 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.0000234 AC: 26 AN: 1111984

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152264 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74436

African (AFR) AF: 0.0000241 AC: 1 AN: 41560

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5180

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10600

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68020

Other (OTH) AF: 0.00 AC: 0 AN: 2112

Alfa AF: 0.0000272 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency (4)
2	-	-	not provided (3)
1	-	-	Methylmalonic acidemia (1)
1	-	-	Methylmalonic aciduria due to complete methylmalonyl-CoA mutase deficiency (1)
1	-	-	METHYLMALONIC ACIDURIA, mut(0) TYPE (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Pathogenic	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.98	D
PhyloP100		7.5
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.9	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.98
MutPred		1.0		Loss of MoRF binding (P = 0.0708)
MVP		0.98
MPC		0.54
ClinPred		1.0	D
GERP RS		5.6
gMVP		0.93
Mutation Taster		=19/81	disease causing (ClinVar)

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: rs483352778; hg19: chr6-49426857; COSMIC: COSV51277513; COSMIC: COSV51277513;