rs144203670

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP5

The NM_022132.5(MCCC2):​c.995G>A​(p.Arg332Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000799 in 1,613,788 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00040 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000047 ( 0 hom. )

Consequence

MCCC2
NM_022132.5 missense

Scores

9
6
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:3

Conservation

PhyloP100: 4.93

Publications

3 publications found
Variant links:
Genes affected
MCCC2 (HGNC:6937): (methylcrotonyl-CoA carboxylase subunit 2) This gene encodes the small 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. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, May 2018]
MCCC2 Gene-Disease associations (from GenCC):
  • 3-methylcrotonyl-CoA carboxylase 2 deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • 3-methylcrotonyl-CoA carboxylase deficiency
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PP5
Variant 5-71635242-G-A is Pathogenic according to our data. Variant chr5-71635242-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 467811.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC2NM_022132.5 linkc.995G>A p.Arg332Gln missense_variant Exon 10 of 17 ENST00000340941.11 NP_071415.1 Q9HCC0-1A0A140VK29

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC2ENST00000340941.11 linkc.995G>A p.Arg332Gln missense_variant Exon 10 of 17 1 NM_022132.5 ENSP00000343657.6 Q9HCC0-1

Frequencies

GnomAD3 genomes
AF:
0.000401
AC:
61
AN:
152186
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00147
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000915
AC:
23
AN:
251448
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.00129
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.0000992
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000465
AC:
68
AN:
1461484
Hom.:
0
Cov.:
32
AF XY:
0.0000440
AC XY:
32
AN XY:
727070
show subpopulations
African (AFR)
AF:
0.00161
AC:
54
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26130
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39684
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86230
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111688
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
4
9
13
18
22
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
AF:
0.000401
AC:
61
AN:
152304
Hom.:
0
Cov.:
33
AF XY:
0.000416
AC XY:
31
AN XY:
74466
show subpopulations
African (AFR)
AF:
0.00147
AC:
61
AN:
41554
American (AMR)
AF:
0.00
AC:
0
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
3
6
9
12
15
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:
0.000176
Hom.:
0
Bravo
AF:
0.000446
ESP6500AA
AF:
0.000454
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000988
AC:
12
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 2 deficiency Pathogenic:2
Apr 13, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 332 of the MCCC2 protein (p.Arg332Gln). This variant is present in population databases (rs144203670, gnomAD 0.1%). This missense change has been observed in individual(s) with clinical features of 3-methylcrotonyl-CoA carboxylase deficiency (internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 467811). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MCCC2 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -

not specified Uncertain:1
May 21, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MCCC2 c.995G>A (p.Arg332Gln) results in a conservative amino acid change located in the Acetyl-coenzyme A carboxyltransferase, C-terminal domain (IPR011763) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 9.1e-05 in 251448 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in MCCC2 causing Methylcrotonyl-CoA Carboxylase Deficiency (9.1e-05 vs 0.0042), allowing no conclusion about variant significance. c.995G>A has been observed in individual(s) affected with Methylcrotonyl-CoA Carboxylase Deficiency (example: Cook_2024, internal data). In at least one of these individuals the variant was found to be carried in trans with a pathogenic variant. These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 38146699). ClinVar contains an entry for this variant (Variation ID: 467811). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Methylcrotonyl-CoA carboxylase deficiency Uncertain:1
Sep 16, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Uncertain:1
Aug 20, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.48
CADD
Pathogenic
28
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.24
T;D;.;.
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.96
D;D;D;T
M_CAP
Pathogenic
0.41
D
MetaRNN
Uncertain
0.54
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.5
.;H;.;.
PhyloP100
4.9
PrimateAI
Benign
0.45
T
PROVEAN
Uncertain
-3.6
.;D;D;D
REVEL
Pathogenic
0.88
Sift
Uncertain
0.0010
.;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D
Polyphen
1.0
.;D;D;.
Vest4
0.53
MVP
0.98
MPC
0.42
ClinPred
0.85
D
GERP RS
5.3
Varity_R
0.86
gMVP
0.83
Mutation Taster
=58/42
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: rs144203670; hg19: chr5-70931069; COSMIC: COSV60156123; COSMIC: COSV60156123; API