NM_172250.3:c.800C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting

The NM_172250.3(MMAA):​c.800C>T​(p.Ala267Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000175 in 1,613,848 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00017 ( 0 hom. )

Consequence

MMAA
NM_172250.3 missense

Scores

3
14
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.38

Publications

0 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 -1 ACMG points.

BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000191 (29/152116) while in subpopulation AMR AF = 0.000982 (15/15280). AF 95% confidence interval is 0.000605. There are 0 homozygotes in GnomAd4. There are 21 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMAANM_172250.3 linkc.800C>T p.Ala267Val missense_variant Exon 5 of 7 ENST00000649156.2 NP_758454.1 Q8IVH4
MMAANM_001375644.1 linkc.800C>T p.Ala267Val missense_variant Exon 5 of 7 NP_001362573.1
MMAAXM_011531684.4 linkc.800C>T p.Ala267Val missense_variant Exon 5 of 7 XP_011529986.1 Q8IVH4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMAAENST00000649156.2 linkc.800C>T p.Ala267Val missense_variant Exon 5 of 7 NM_172250.3 ENSP00000497008.1 Q8IVH4

Frequencies

GnomAD3 genomes
AF:
0.000191
AC:
29
AN:
152116
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000982
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:
0.000191
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000111
AC:
28
AN:
251362
AF XY:
0.000125
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000260
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000150
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000173
AC:
253
AN:
1461732
Hom.:
0
Cov.:
31
AF XY:
0.000165
AC XY:
120
AN XY:
727182
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.000313
AC:
14
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000201
AC:
224
AN:
1111890
Other (OTH)
AF:
0.000215
AC:
13
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
12
24
35
47
59
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000191
AC:
29
AN:
152116
Hom.:
0
Cov.:
32
AF XY:
0.000283
AC XY:
21
AN XY:
74310
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41416
American (AMR)
AF:
0.000982
AC:
15
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000191
AC:
13
AN:
68022
Other (OTH)
AF:
0.000478
AC:
1
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
1
3
4
6
7
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
Bravo
AF:
0.000181
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.000140
AC:
17
EpiCase
AF:
0.000164
EpiControl
AF:
0.000237

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblA type Uncertain:3
Oct 31, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 267 of the MMAA protein (p.Ala267Val). This variant is present in population databases (rs138854691, gnomAD 0.03%). 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: 466218). 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. -

Jul 07, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 16, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Uncertain:1
Sep 24, 2020
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.39
BayesDel_addAF
Uncertain
0.11
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.79
D;.;D;D;D;D
Eigen
Uncertain
0.48
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.41
.;T;.;.;D;D
M_CAP
Uncertain
0.23
D
MetaRNN
Uncertain
0.70
D;D;D;D;D;D
MetaSVM
Uncertain
0.77
D
MutationAssessor
Pathogenic
2.9
M;.;M;M;M;.
PhyloP100
7.4
PrimateAI
Uncertain
0.66
T
PROVEAN
Uncertain
-3.4
.;.;D;.;.;.
REVEL
Pathogenic
0.81
Sift
Uncertain
0.0030
.;.;D;.;.;.
Sift4G
Uncertain
0.039
.;.;D;.;.;D
Polyphen
0.25
B;.;B;B;B;.
Vest4
0.78, 0.77
MVP
0.94
MPC
0.26
ClinPred
0.81
D
GERP RS
5.4
Varity_R
0.84
gMVP
0.85
Mutation Taster
=29/71
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs138854691; hg19: chr4-146572280; API