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GeneBe

12-109554288-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBS1_Supporting

The NM_052845.4(MMAB):c.*2740G>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 0.000207 in 454,028 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 0.00035 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

MMAB
NM_052845.4 3_prime_UTR

Scores

2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.288
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.85).
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000355 (54/152230) while in subpopulation AFR AF= 0.000891 (37/41532). AF 95% confidence interval is 0.000664. There are 0 homozygotes in gnomad4. There are 28 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MMABNM_052845.4 linkuse as main transcriptc.*2740G>A 3_prime_UTR_variant 9/9 ENST00000545712.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MMABENST00000545712.7 linkuse as main transcriptc.*2740G>A 3_prime_UTR_variant 9/91 NM_052845.4 P1

Frequencies

GnomAD3 genomes
AF:
0.000355
AC:
54
AN:
152112
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000894
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000393
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000415
Gnomad FIN
AF:
0.0000943
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00144
GnomAD3 exomes
AF:
0.000222
AC:
29
AN:
130484
Hom.:
0
AF XY:
0.000211
AC XY:
15
AN XY:
71230
show subpopulations
Gnomad AFR exome
AF:
0.000493
Gnomad AMR exome
AF:
0.000616
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000447
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000141
Gnomad OTH exome
AF:
0.000749
GnomAD4 exome
AF:
0.000133
AC:
40
AN:
301798
Hom.:
0
Cov.:
0
AF XY:
0.000116
AC XY:
20
AN XY:
171998
show subpopulations
Gnomad4 AFR exome
AF:
0.000468
Gnomad4 AMR exome
AF:
0.000660
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000503
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000378
Gnomad4 OTH exome
AF:
0.000285
GnomAD4 genome
AF:
0.000355
AC:
54
AN:
152230
Hom.:
0
Cov.:
32
AF XY:
0.000376
AC XY:
28
AN XY:
74416
show subpopulations
Gnomad4 AFR
AF:
0.000891
Gnomad4 AMR
AF:
0.000392
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000415
Gnomad4 FIN
AF:
0.0000943
Gnomad4 NFE
AF:
0.0000735
Gnomad4 OTH
AF:
0.00142
Alfa
AF:
0.0000434
Hom.:
0
Bravo
AF:
0.000385
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblB type Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.85
Cadd
Benign
2.4
Dann
Benign
0.47

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.

Other links and lift over

dbSNP: rs139886832; hg19: chr12-109992093; API