Genetic Variant MMAB:c.*3043T>G (chr12-109553985-A-C) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBS1_Supporting

The NM_052845.4(MMAB):c.*3043T>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000304 in 453,988 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 0.00032 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00030 ( 0 hom. )

Consequence

MMAB
NM_052845.4 3_prime_UTR

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.38

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 -3 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.45).

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000315 (48/152188) while in subpopulation NFE AF = 0.000661 (45/68036). AF 95% confidence interval is 0.000507. There are 0 homozygotes in GnomAd4. There are 22 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

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.*3043T>G		3_prime_UTR	Exon 9 of 9	NP_443077.1	Q96EY8
	MMAB	NR_038118.2		n.3907T>G		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.*3043T>G		3_prime_UTR	Exon 9 of 9	ENSP00000445920.1	Q96EY8

Frequencies

GnomAD3 genomes

AF:

0.000315

AC:

AN:

152188

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:

0.000188

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000661

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000276

AC:

AN:

130498

AF XY:

0.000253

show subpopulations

Gnomad AFR exome

AF:

0.000164

Gnomad AMR exome

AF:

0.000123

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000643

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000298

AC:

AN:

301800

Hom.:

Cov.:

AF XY:

0.000267

AC XY:

AN XY:

172000

show subpopulations

African (AFR)

AF:

0.000234

AC:

AN:

8554

American (AMR)

AF:

0.000110

AC:

AN:

27274

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:

0.000243

AC:

AN:

12366

Middle Eastern (MID)

AF:

0.00

AC:

AN:

1150

European-Non Finnish (NFE)

AF:

0.000491

AC:

AN:

158766

Other (OTH)

AF:

0.000285

AC:

AN:

14044

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.491

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:

0.000315

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.000296

AC XY:

AN XY:

74358

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41432

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:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.000188

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000661

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.517

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:

0.000598

Hom.:

Bravo

AF:

0.000397

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

-0.45

CADD

Benign

(source)

DANN

Benign

0.75

PhyloP100

1.4

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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