rs150327768

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The NM_022132.5(MCCC2):​c.1559A>C​(p.Tyr520Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000595 in 1,614,052 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y520C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000065 ( 0 hom. )

Consequence

MCCC2
NM_022132.5 missense

Scores

13
5
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 8.92

Publications

8 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: Pathogenic. The variant received 11 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_022132.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr5-71652739-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2676478.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.981
PP5
Variant 5-71652739-A-C is Pathogenic according to our data. Variant chr5-71652739-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 467805.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC2NM_022132.5 linkc.1559A>C p.Tyr520Ser missense_variant Exon 16 of 17 ENST00000340941.11 NP_071415.1 Q9HCC0-1A0A140VK29
MCCC2NM_001363147.1 linkc.1445A>C p.Tyr482Ser missense_variant Exon 15 of 16 NP_001350076.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC2ENST00000340941.11 linkc.1559A>C p.Tyr520Ser missense_variant Exon 16 of 17 1 NM_022132.5 ENSP00000343657.6 Q9HCC0-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152218
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251390
AF XY:
0.0000147
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:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000650
AC:
95
AN:
1461834
Hom.:
0
Cov.:
32
AF XY:
0.0000550
AC XY:
40
AN XY:
727222
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
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:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
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:
0.0000845
AC:
94
AN:
1111966
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
6
12
17
23
29
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.00000657
AC:
1
AN:
152218
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 2 deficiency Pathogenic:1
Aug 09, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense change has been observed in individual(s) with 3-methylcrotonyl-CoA carboxylase (3MCC) deficiency (PMID: 21071250; Invitae). For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MCCC2 protein function. ClinVar contains an entry for this variant (Variation ID: 467805). This variant is present in population databases (rs150327768, gnomAD 0.004%). This sequence change replaces tyrosine, which is neutral and polar, with serine, which is neutral and polar, at codon 520 of the MCCC2 protein (p.Tyr520Ser). -

not specified Uncertain:1
Jun 06, 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.1559A>C (p.Tyr520Ser) results in a non-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 all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 2e-05 in 251390 control chromosomes. c.1559A>C has been observed in individual(s) affected with Methylcrotonyl-CoA Carboxylase Deficiency (Nguyen_2011, Internal data). 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 have been ascertained in the context of this evaluation (PMID: 21071250). ClinVar contains an entry for this variant (Variation ID: 467805). 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

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.43
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.62
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.95
D
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.75
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.5
H
PhyloP100
8.9
PrimateAI
Uncertain
0.64
T
PROVEAN
Pathogenic
-8.6
D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.0030
D
Polyphen
1.0
D
Vest4
0.91
MVP
0.99
MPC
0.62
ClinPred
1.0
D
GERP RS
5.4
Varity_R
0.97
gMVP
0.96
Mutation Taster
=8/92
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
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: rs150327768; hg19: chr5-70948566; API