dbSNP rs768176676: MMAB:p.Val188Met (chr12-109561062-C-T) – ACMG Classification: Pathogenic (16 pts)

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong

The NM_052845.4(MMAB):c.562G>A(p.Val188Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000279 in 1,610,614 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. V188G) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 30)

Exomes 𝑓: 0.000026 ( 0 hom. )

Consequence

MMAB
NM_052845.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6U:1

Conservation

PhyloP100: 4.02

Publications

6 publications found

Variant links:

Genes affected

MMAB (HGNC:19331): (metabolism of cobalamin associated B) This gene encodes a protein that catalyzes the final step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12-containing coenzyme for methylmalonyl-CoA mutase. Mutations in the gene are the cause of vitamin B12-dependent methylmalonic aciduria linked to the cblB complementation group. Alternatively spliced transcript variants have been found. [provided by RefSeq, Apr 2011]

MMAB Gene-Disease associations (from GenCC):

methylmalonic acidemia
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
methylmalonic aciduria, cblB type
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Myriad Women’s Health, G2P

MMAB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PM1

In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_052845.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr12-109561061-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 225186.Status of the report is no_assertion_criteria_provided, 0 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.937

PP5

Variant 12-109561062-C-T is Pathogenic according to our data. Variant chr12-109561062-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 551432.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052845.4. 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
	MMAB	NM_052845.4	MANE Select	c.562G>A	p.Val188Met	missense	Exon 7 of 9	NP_443077.1	Q96EY8
	MMAB	NR_038118.2		n.673G>A		non_coding_transcript_exon	Exon 8 of 10

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
MMAB	ENST00000545712.7	TSL:1 MANE Select	c.562G>A	p.Val188Met	missense	Exon 7 of 9	ENSP00000445920.1	Q96EY8
MMAB	ENST00000878519.1		c.625G>A	p.Val209Met	missense	Exon 8 of 10	ENSP00000548578.1
MMAB	ENST00000878520.1		c.562G>A	p.Val188Met	missense	Exon 7 of 8	ENSP00000548579.1

Frequencies

GnomAD3 genomes

AF:

0.0000461

AC:

AN:

151914

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000968

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000241

AC:

AN:

249032

AF XY:

0.0000370

show subpopulations

Gnomad AFR exome

AF:

0.000124

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000996

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000499

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000261

AC:

AN:

1458700

Hom.:

Cov.:

AF XY:

0.0000276

AC XY:

AN XY:

725928

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26132

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000199

AC:

AN:

50312

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000261

AC:

AN:

1111966

Other (OTH)

AF:

0.0000331

AC:

AN:

60368

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.471

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000461

AC:

AN:

151914

Hom.:

Cov.:

AF XY:

0.0000539

AC XY:

AN XY:

74206

show subpopulations

African (AFR)

AF:

0.0000968

AC:

AN:

41336

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5152

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

67960

Other (OTH)

AF:

0.00

AC:

AN:

2080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.589

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000387

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000165

AC:

ClinVar

ClinVar submissions

Significance:Pathogenic/Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Methylmalonic aciduria, cblB type (7)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Pathogenic

0.31

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.81

Eigen

Pathogenic

0.76

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.67

MetaRNN

Pathogenic

0.94

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.6

PhyloP100

4.0

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-2.5

REVEL

Pathogenic

0.94

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0020

Polyphen

1.0

Vest4

0.74

MutPred

0.72

Gain of MoRF binding (P = 0.0974)

MVP

0.98

MPC

0.73

ClinPred

0.90

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.70

gMVP

0.86

Mutation Taster

=14/86

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over