NM_015506.3:c.88T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP2PP3_Moderate

The NM_015506.3(MMACHC):​c.88T>C​(p.Trp30Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

MMACHC
NM_015506.3 missense

Scores

11
5
2

Clinical Significance

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

Conservation

PhyloP100: 7.48

Publications

1 publications found
Variant links:
Genes affected
MMACHC (HGNC:24525): (metabolism of cobalamin associated C) The exact function of the protein encoded by this gene is not known, however, its C-terminal region shows similarity to TonB, a bacterial protein involved in energy transduction for cobalamin (vitamin B12) uptake. Hence, it is postulated that this protein may have a role in the binding and intracellular trafficking of cobalamin. Mutations in this gene are associated with methylmalonic aciduria and homocystinuria type cblC. [provided by RefSeq, Oct 2009]
MMACHC Gene-Disease associations (from GenCC):
  • methylmalonic aciduria and homocystinuria type cblC
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Myriad Women’s Health, ClinGen, G2P, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a chain Cyanocobalamin reductase / alkylcobalamin dealkylase (size 281) in uniprot entity MMAC_HUMAN there are 42 pathogenic changes around while only 16 benign (72%) in NM_015506.3
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 28 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: -1.0759 (below the threshold of 3.09). Trascript score misZ: -0.13772 (below the threshold of 3.09). GenCC associations: The gene is linked to methylmalonic aciduria and homocystinuria type cblC.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.934

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015506.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MMACHC
NM_015506.3
MANE Select
c.88T>Cp.Trp30Arg
missense
Exon 2 of 4NP_056321.2
MMACHC
NM_001330540.2
c.-84T>C
5_prime_UTR
Exon 2 of 4NP_001317469.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MMACHC
ENST00000401061.9
TSL:2 MANE Select
c.88T>Cp.Trp30Arg
missense
Exon 2 of 4ENSP00000383840.4
MMACHC
ENST00000616135.1
TSL:2
c.-84T>C
5_prime_UTR
Exon 2 of 5ENSP00000478859.1
MMACHC
ENST00000933807.1
c.82-850T>C
intron
N/AENSP00000603866.1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152170
Hom.:
0
Cov.:
31
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
249258
AF XY:
0.0000148
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:
0.0000265
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000369
AC:
54
AN:
1461852
Hom.:
0
Cov.:
32
AF XY:
0.0000303
AC XY:
22
AN XY:
727224
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
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:
0.0000477
AC:
53
AN:
1111998
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.490
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000329
AC:
5
AN:
152170
Hom.:
0
Cov.:
31
AF XY:
0.0000538
AC XY:
4
AN XY:
74344
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
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:
0.0000868
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.00000827
AC:
1

ClinVar

ClinVar submissions as Germline
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
4
-
Cobalamin C disease (4)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.83
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.49
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.79
D
Eigen
Pathogenic
0.79
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.56
T
M_CAP
Pathogenic
0.36
D
MetaRNN
Pathogenic
0.93
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
7.5
PrimateAI
Pathogenic
0.80
D
PROVEAN
Pathogenic
-10
D
REVEL
Pathogenic
0.94
Sift
Benign
0.081
T
Sift4G
Uncertain
0.0090
D
Polyphen
1.0
D
Vest4
0.94
MutPred
0.73
Gain of methylation at W30 (P = 0.0494)
MVP
0.98
MPC
0.080
ClinPred
1.0
D
GERP RS
5.4
Varity_R
0.92
gMVP
0.84
Mutation Taster
=41/59
disease causing

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: rs745419717; hg19: chr1-45973034; API