rs763935916

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_052845.4(MMAB):​c.197-1G>T variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000217 in 1,612,208 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

MMAB
NM_052845.4 splice_acceptor, intron

Scores

5
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:13O:1

Conservation

PhyloP100: 6.94

Publications

5 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6.5, offset of 10, new splice context is: ttttccacatggttttctAGtac. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PP5
Variant 12-109568864-C-A is Pathogenic according to our data. Variant chr12-109568864-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 219008.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.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MMAB
NM_052845.4
MANE Select
c.197-1G>T
splice_acceptor intron
N/ANP_443077.1Q96EY8
MMAB
NR_038118.2
n.221-1G>T
splice_acceptor intron
N/A

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MMAB
ENST00000545712.7
TSL:1 MANE Select
c.197-1G>T
splice_acceptor intron
N/AENSP00000445920.1Q96EY8
MMAB
ENST00000878519.1
c.197-1G>T
splice_acceptor intron
N/AENSP00000548578.1
MMAB
ENST00000878520.1
c.197-1G>T
splice_acceptor intron
N/AENSP00000548579.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151900
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251468
AF XY:
0.0000662
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1460308
Hom.:
0
Cov.:
30
AF XY:
0.0000385
AC XY:
28
AN XY:
726624
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33446
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.000313
AC:
27
AN:
86212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1110576
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.436
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000132
AC:
2
AN:
151900
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74190
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41374
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10474
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67974
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000436
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000247
AC:
3

ClinVar

ClinVar submissions
Significance:Pathogenic
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
10
-
-
Methylmalonic aciduria, cblB type (11)
2
-
-
Methylmalonic acidemia (2)
1
-
-
Methylmalonic aciduria (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.40
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.96
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
6.9
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.80
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.61
Position offset: -11
DS_AL_spliceai
0.80
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs763935916; hg19: chr12-110006669; API