chr12-109573393-G-A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_052845.4(MMAB):​c.88C>T​(p.Pro30Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,612,352 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

MMAB
NM_052845.4 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.450

Publications

1 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]
MVK (HGNC:7530): (mevalonate kinase) This gene encodes the peroxisomal enzyme mevalonate kinase. Mevalonate is a key intermediate, and mevalonate kinase a key early enzyme, in isoprenoid and sterol synthesis. Mevalonate kinase deficiency caused by mutation of this gene results in mevalonic aciduria, a disease characterized psychomotor retardation, failure to thrive, hepatosplenomegaly, anemia and recurrent febrile crises. Defects in this gene also cause hyperimmunoglobulinaemia D and periodic fever syndrome, a disorder characterized by recurrent episodes of fever associated with lymphadenopathy, arthralgia, gastrointestinal dismay and skin rash. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]
MVK Gene-Disease associations (from GenCC):
  • porokeratosis 3, disseminated superficial actinic type
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
  • hyperimmunoglobulinemia D with periodic fever
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
  • mevalonic aciduria
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
  • disseminated superficial actinic porokeratosis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • porokeratosis of Mibelli
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.03755933).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMABNM_052845.4 linkc.88C>T p.Pro30Ser missense_variant Exon 1 of 9 ENST00000545712.7 NP_443077.1 Q96EY8
MVKXM_047428873.1 linkc.108G>A p.Gly36Gly synonymous_variant Exon 1 of 11 XP_047284829.1
MMABNR_038118.2 linkn.112C>T non_coding_transcript_exon_variant Exon 1 of 10
MVKXM_017019313.3 linkc.-193G>A 5_prime_UTR_variant Exon 1 of 10 XP_016874802.1 F5H8H2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMABENST00000545712.7 linkc.88C>T p.Pro30Ser missense_variant Exon 1 of 9 1 NM_052845.4 ENSP00000445920.1 Q96EY8

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152220
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:
0.000620
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000452
AC:
11
AN:
243418
AF XY:
0.0000376
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000158
AC:
23
AN:
1460014
Hom.:
0
Cov.:
30
AF XY:
0.0000179
AC XY:
13
AN XY:
726314
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33460
American (AMR)
AF:
0.0000448
AC:
2
AN:
44654
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26096
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39670
South Asian (SAS)
AF:
0.000221
AC:
19
AN:
86116
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52372
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5618
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111738
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60290
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.0000197
AC:
3
AN:
152338
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74486
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41576
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.000621
AC:
3
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00
Hom.:
0
ExAC
AF:
0.0000578
AC:
7

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblB type Uncertain:2
May 13, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missense variant in c.88C>T (p.Pro30Ser) in MMAB gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant has not been reported to the ClinVar database. This variant has been submitted allele frequency 0.0045 % in the gnomAD and novel in 1000 genome database. The amino acid Pro at position 30 is changed to a Ser changing protein sequence and it might alter its composition and physicochemical properties. For these reasons, this variant has been classified as Uncertain Significance (VUS). -

Inborn genetic diseases Uncertain:1
Aug 12, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.88C>T (p.P30S) alteration is located in exon 1 (coding exon 1) of the MMAB gene. This alteration results from a C to T substitution at nucleotide position 88, causing the proline (P) at amino acid position 30 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.090
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.28
CADD
Benign
17
DANN
Benign
0.94
DEOGEN2
Benign
0.14
T;.;T
Eigen
Benign
-0.70
Eigen_PC
Benign
-0.64
FATHMM_MKL
Uncertain
0.79
D
LIST_S2
Benign
0.69
T;T;T
M_CAP
Benign
0.020
T
MetaRNN
Benign
0.038
T;T;T
MetaSVM
Benign
-0.86
T
MutationAssessor
Benign
0.34
N;.;.
PhyloP100
0.45
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-0.47
N;.;.
REVEL
Benign
0.12
Sift
Benign
0.37
T;.;.
Sift4G
Benign
0.22
T;T;T
Polyphen
0.0010
B;.;.
Vest4
0.090
MutPred
0.37
Gain of helix (P = 0.0117);Gain of helix (P = 0.0117);Gain of helix (P = 0.0117);
MVP
0.84
MPC
0.23
ClinPred
0.034
T
GERP RS
-0.52
PromoterAI
0.0085
Neutral
Varity_R
0.055
gMVP
0.29
Mutation Taster
=95/5
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs550461600; hg19: chr12-110011198; API