rs200483477

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 7P and 2B. PM1PM2PM5PP2BP4_Moderate

The NM_015506.3(MMACHC):​c.181C>G​(p.Arg61Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R61W) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MMACHC
NM_015506.3 missense

Scores

6
12

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.24

Publications

0 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: Uncertain_significance. The variant received 5 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;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-45507456-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 854802.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
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.
BP4
Computational evidence support a benign effect (MetaRNN=0.25217056).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMACHCNM_015506.3 linkc.181C>G p.Arg61Gly missense_variant Exon 2 of 4 ENST00000401061.9 NP_056321.2
MMACHCNM_001330540.2 linkc.10C>G p.Arg4Gly missense_variant Exon 2 of 4 NP_001317469.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMACHCENST00000401061.9 linkc.181C>G p.Arg61Gly missense_variant Exon 2 of 4 2 NM_015506.3 ENSP00000383840.4
MMACHCENST00000616135.1 linkc.10C>G p.Arg4Gly missense_variant Exon 2 of 5 2 ENSP00000478859.1

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461874
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1112004
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

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
Cov.:
31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Uncertain
0.099
D
BayesDel_noAF
Benign
-0.10
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.76
D;T
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.14
FATHMM_MKL
Benign
0.48
N
LIST_S2
Benign
0.81
T;T
M_CAP
Benign
0.039
D
MetaRNN
Benign
0.25
T;T
MetaSVM
Uncertain
0.27
D
MutationAssessor
Uncertain
2.5
M;.
PhyloP100
1.2
PrimateAI
Benign
0.20
T
PROVEAN
Uncertain
-3.2
D;.
REVEL
Benign
0.25
Sift
Benign
0.12
T;.
Sift4G
Benign
0.084
T;T
Vest4
0.31
ClinPred
0.56
D
GERP RS
4.4
Varity_R
0.33
gMVP
0.43
Mutation Taster
=73/27
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: rs200483477; hg19: chr1-45973127; API