Genetic Variant MMAB:c.*2783G>A (chr12-109554245-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_052845.4(MMAB):c.*2783G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000374 in 453,976 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000043 ( 0 hom. )

Consequence

MMAB
NM_052845.4 3_prime_UTR

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.112

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.81).

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.*2783G>A		3_prime_UTR	Exon 9 of 9	NP_443077.1	Q96EY8
	MMAB	NR_038118.2		n.3647G>A		non_coding_transcript_exon	Exon 10 of 10

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMAB	ENST00000545712.7	TSL:1 MANE Select	c.*2783G>A		3_prime_UTR	Exon 9 of 9	ENSP00000445920.1	Q96EY8

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000307

AC:

AN:

130424

AF XY:

0.0000281

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000604

Gnomad OTH exome

AF:

0.000250

GnomAD4 exome

AF:

0.0000431

AC:

AN:

301780

Hom.:

Cov.:

AF XY:

0.0000407

AC XY:

AN XY:

171988

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

8554

American (AMR)

AF:

0.00

AC:

AN:

27272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

10786

East Asian (EAS)

AF:

0.00

AC:

AN:

9210

South Asian (SAS)

AF:

0.00

AC:

AN:

59650

European-Finnish (FIN)

AF:

0.00

AC:

AN:

12368

Middle Eastern (MID)

AF:

0.00

AC:

AN:

1150

European-Non Finnish (NFE)

AF:

0.0000819

AC:

AN:

158746

Other (OTH)

AF:

0.00

AC:

AN:

14044

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.490

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:

0.0000263

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74348

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41448

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:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68042

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

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:

0.00

Hom.:

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Methylmalonic aciduria, cblB type (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.81

CADD

Benign

4.6

(source)

DANN

Benign

0.35

PhyloP100

0.11

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