4-145639146-A-G

Variant summary

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

The NM_172250.3(MMAA):​c.7A>G​(p.Met3Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,614,216 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 0.000092 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

MMAA
NM_172250.3 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -0.422

Publications

1 publications found
Variant links:
Genes affected
MMAA (HGNC:18871): (metabolism of cobalamin associated A) The protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase. Defects in this gene are a cause of methylmalonic aciduria. [provided by RefSeq, Jul 2008]
MMAA Gene-Disease associations (from GenCC):
  • methylmalonic aciduria, cblA type
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Myriad Women’s Health, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, G2P

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=0.036696404).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMAANM_172250.3 linkc.7A>G p.Met3Val missense_variant Exon 2 of 7 ENST00000649156.2 NP_758454.1 Q8IVH4
MMAANM_001375644.1 linkc.7A>G p.Met3Val missense_variant Exon 2 of 7 NP_001362573.1
MMAAXM_011531684.4 linkc.7A>G p.Met3Val missense_variant Exon 2 of 7 XP_011529986.1 Q8IVH4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMAAENST00000649156.2 linkc.7A>G p.Met3Val missense_variant Exon 2 of 7 NM_172250.3 ENSP00000497008.1 Q8IVH4

Frequencies

GnomAD3 genomes
AF:
0.0000854
AC:
13
AN:
152242
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000289
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:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251418
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.000369
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1461856
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727226
show subpopulations
African (AFR)
AF:
0.000418
AC:
14
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112004
Other (OTH)
AF:
0.0000993
AC:
6
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.449
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000919
AC:
14
AN:
152360
Hom.:
0
Cov.:
32
AF XY:
0.0000805
AC XY:
6
AN XY:
74504
show subpopulations
African (AFR)
AF:
0.000313
AC:
13
AN:
41598
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.000131
Hom.:
0
Bravo
AF:
0.0000793
ExAC
AF:
0.0000247
AC:
3
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblA type Uncertain:1
Sep 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 3 of the MMAA protein (p.Met3Val). This variant is present in population databases (rs527340737, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with MMAA-related conditions. ClinVar contains an entry for this variant (Variation ID: 1479375). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MMAA protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Inborn genetic diseases Uncertain:1
May 02, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.7A>G (p.M3V) alteration is located in exon 2 (coding exon 1) of the MMAA gene. This alteration results from a A to G substitution at nucleotide position 7, causing the methionine (M) at amino acid position 3 to be replaced by a valine (V). 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
0.057
BayesDel_addAF
Benign
-0.35
T
BayesDel_noAF
Benign
-0.43
CADD
Benign
0.028
DANN
Benign
0.60
DEOGEN2
Benign
0.16
T;.;T;T;T;T
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.3
FATHMM_MKL
Benign
0.022
N
LIST_S2
Benign
0.32
.;T;.;.;T;T
M_CAP
Benign
0.080
D
MetaRNN
Benign
0.037
T;T;T;T;T;T
MetaSVM
Benign
-0.62
T
MutationAssessor
Benign
0.42
N;.;N;N;N;.
PhyloP100
-0.42
PrimateAI
Benign
0.22
T
PROVEAN
Benign
-0.25
.;.;N;.;.;.
REVEL
Benign
0.18
Sift
Benign
0.74
.;.;T;.;.;.
Sift4G
Uncertain
0.016
.;.;D;.;.;D
Polyphen
0.0
B;.;B;B;B;.
Vest4
0.047, 0.082
MVP
0.32
MPC
0.12
ClinPred
0.014
T
GERP RS
-7.7
Varity_R
0.038
gMVP
0.37
Mutation Taster
=96/4
polymorphism

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

Other links and lift over

dbSNP: rs527340737; hg19: chr4-146560298; COSMIC: COSV99850083; COSMIC: COSV99850083; API