3-183071223-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_020166.5(MCCC1):​c.626G>A​(p.Gly209Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,858 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 (★★). Synonymous variant affecting the same amino acid position (i.e. G209G) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MCCC1
NM_020166.5 missense

Scores

15
3
1

Clinical Significance

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

Conservation

PhyloP100: 7.50

Publications

3 publications found
Variant links:
Genes affected
MCCC1 (HGNC:6936): (methylcrotonyl-CoA carboxylase subunit 1) This gene encodes the large subunit of 3-methylcrotonyl-CoA carboxylase. This enzyme functions as a heterodimer and catalyzes the carboxylation of 3-methylcrotonyl-CoA to form 3-methylglutaconyl-CoA. Mutations in this gene are associated with 3-Methylcrotonylglycinuria, an autosomal recessive disorder of leucine catabolism. [provided by RefSeq, Jul 2008]
MCCC1 Gene-Disease associations (from GenCC):
  • 3-methylcrotonyl-CoA carboxylase 1 deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • 3-methylcrotonyl-CoA carboxylase deficiency
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.981

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC1NM_020166.5 linkc.626G>A p.Gly209Asp missense_variant Exon 6 of 19 ENST00000265594.9 NP_064551.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC1ENST00000265594.9 linkc.626G>A p.Gly209Asp missense_variant Exon 6 of 19 1 NM_020166.5 ENSP00000265594.4

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251464
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461858
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111988
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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.:
33
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 1 deficiency Uncertain:2
Oct 10, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 01, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 209 of the MCCC1 protein (p.Gly209Asp). This variant is present in population databases (rs186209189, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with MCCC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 569048). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -

MCCC1-related disorder Uncertain:1
Aug 07, 2023
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The MCCC1 c.626G>A variant is predicted to result in the amino acid substitution p.Gly209Asp. To our knowledge, this variant has not been reported in the literature. A different substitution affecting the same amino acid (p.Gly209Ala) was reported along with a loss-of-function variant in a patient with 3-MCC deficiency (Yang et al. 2015. PubMed ID: 25382614). Of note, the p.Gly209 amino acid is located in the enzyme ATP binding pocket (Yang et al. 2015. PubMed ID: 25382614). This variant is reported in 0.0058% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/3-182789011-C-T). Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.45
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.91
D;D;D;D;D
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
1.0
D;D;D;D;D
M_CAP
Uncertain
0.23
D
MetaRNN
Pathogenic
0.98
D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.5
H;.;.;.;.
PhyloP100
7.5
PrimateAI
Uncertain
0.72
T
PROVEAN
Pathogenic
-6.6
D;D;.;.;D
REVEL
Pathogenic
0.90
Sift
Pathogenic
0.0
D;D;.;.;D
Sift4G
Pathogenic
0.0
D;D;D;D;.
Polyphen
1.0
D;D;.;.;D
Vest4
0.84
MutPred
0.90
Loss of methylation at R208 (P = 0.0334);.;.;.;.;
MVP
0.99
MPC
0.68
ClinPred
1.0
D
GERP RS
5.9
Varity_R
0.95
gMVP
0.97
Mutation Taster
=7/93
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: rs186209189; hg19: chr3-182789011; API