chr1-45508910-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_015506.3(MMACHC):ā€‹c.544T>Cā€‹(p.Cys182Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,886 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 (ā˜…ā˜…). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C182Y) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes š‘“: 0.0000082 ( 0 hom. )

Consequence

MMACHC
NM_015506.3 missense

Scores

12
4
3

Clinical Significance

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

Conservation

PhyloP100: 7.52
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1
In a chain Cyanocobalamin reductase / alkylcobalamin dealkylase (size 281) in uniprot entity MMAC_HUMAN there are 50 pathogenic changes around while only 14 benign (78%) in NM_015506.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.957

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MMACHCNM_015506.3 linkuse as main transcriptc.544T>C p.Cys182Arg missense_variant 4/4 ENST00000401061.9
MMACHCNM_001330540.2 linkuse as main transcriptc.373T>C p.Cys125Arg missense_variant 4/4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MMACHCENST00000401061.9 linkuse as main transcriptc.544T>C p.Cys182Arg missense_variant 4/42 NM_015506.3 P1
MMACHCENST00000616135.1 linkuse as main transcriptc.373T>C p.Cys125Arg missense_variant 4/52

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000401
AC:
1
AN:
249556
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135390
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461886
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
727244
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000540
Gnomad4 OTH exome
AF:
0.0000662
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000756

ClinVar

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

Submissions by phenotype

Cobalamin C disease Uncertain:3
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsJul 26, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingCounsylMar 28, 2017- -
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabApr 11, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.62
BayesDel_addAF
Pathogenic
0.52
D
BayesDel_noAF
Pathogenic
0.50
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.86
D;T
Eigen
Pathogenic
0.75
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.69
T;T
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.96
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.8
M;.
MutationTaster
Benign
1.0
D
PrimateAI
Uncertain
0.78
T
PROVEAN
Pathogenic
-6.4
D;.
REVEL
Pathogenic
0.94
Sift
Benign
0.11
T;.
Sift4G
Uncertain
0.0030
D;D
Polyphen
1.0
D;.
Vest4
0.88
MutPred
0.86
Gain of disorder (P = 0.0031);.;
MVP
0.95
MPC
0.074
ClinPred
0.97
D
GERP RS
5.7
Varity_R
0.93
gMVP
0.97

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs955468279; hg19: chr1-45974582; API