Genetic Variant MMAB:c.*3178C>A (chr12-109553850-G-T) – ACMG Classification: Benign (-20 pts)

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBA1

The NM_052845.4(MMAB):c.*3178C>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 0.00969 in 454,080 control chromosomes in the GnomAD database, including 146 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.023 ( 119 hom., cov: 33)

Exomes 𝑓: 0.0030 ( 27 hom. )

Consequence

MMAB
NM_052845.4 3_prime_UTR

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:2

Conservation

PhyloP100: 2.88

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.77).

BP6

Variant 12-109553850-G-T is Benign according to our data. Variant chr12-109553850-G-T is described in ClinVar as [Benign]. Clinvar id is 307001.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BA1

GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0769 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMAB	NM_052845.4 link	c.*3178C>A		3_prime_UTR_variant	Exon 9 of 9	ENST00000545712.7	NP_443077.1	Q96EY8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMAB	ENST00000545712 link	c.*3178C>A		3_prime_UTR_variant	Exon 9 of 9	1	NM_052845.4	ENSP00000445920.1		Q96EY8

Frequencies

GnomAD3 genomes

AF:

0.0230

AC:

3497

AN:

152220

Hom.:

119

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0793

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00884

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000558

Gnomad OTH

AF:

0.0172

GnomAD3 exomes

AF:

0.00471

AC:

614

AN:

130476

Hom.:

AF XY:

0.00374

AC XY:

266

AN XY:

71218

show subpopulations

Gnomad AFR exome

AF:

0.0773

Gnomad AMR exome

AF:

0.00443

Gnomad ASJ exome

AF:

0.000123

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000442

Gnomad OTH exome

AF:

0.00299

GnomAD4 exome

AF:

0.00300

AC:

904

AN:

301742

Hom.:

Cov.:

AF XY:

0.00213

AC XY:

366

AN XY:

171966

show subpopulations

Gnomad4 AFR exome

AF:

0.0759

Gnomad4 AMR exome

AF:

0.00444

Gnomad4 ASJ exome

AF:

0.0000927

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000168

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000271

Gnomad4 OTH exome

AF:

0.00541

GnomAD4 genome

AF:

0.0230

AC:

3498

AN:

152338

Hom.:

119

Cov.:

AF XY:

0.0214

AC XY:

1595

AN XY:

74484

show subpopulations

Gnomad4 AFR

AF:

0.0791

Gnomad4 AMR

AF:

0.00882

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000544

Gnomad4 OTH

AF:

0.0170

Alfa

AF:

0.0124

Hom.:

Bravo

AF:

0.0264

Asia WGS

AF:

0.00260

AC:

AN:

3478

ClinVar

Significance: Benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblB type

Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided

Benign:1

Breakthrough Genomics, Breakthrough Genomics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.77

CADD

Benign

DANN

Benign

0.65

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over