rs202083272

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_020166.5(MCCC1):​c.758C>T​(p.Pro253Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,512 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). Synonymous variant affecting the same amino acid position (i.e. P253P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

MCCC1
NM_020166.5 missense

Scores

12
5
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4

Conservation

PhyloP100: 9.47

Publications

5 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 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.967
PP5
Variant 3-183071002-G-A is Pathogenic according to our data. Variant chr3-183071002-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 476399.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC1NM_020166.5 linkc.758C>T p.Pro253Leu missense_variant Exon 7 of 19 ENST00000265594.9 NP_064551.3 Q96RQ3A0A0S2Z693

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC1ENST00000265594.9 linkc.758C>T p.Pro253Leu missense_variant Exon 7 of 19 1 NM_020166.5 ENSP00000265594.4 Q96RQ3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152020
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000725
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:
0.0000120
AC:
3
AN:
250760
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.000185
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461492
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727000
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44684
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86210
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53378
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111784
Other (OTH)
AF:
0.00
AC:
0
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000197
AC:
3
AN:
152020
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74256
show subpopulations
African (AFR)
AF:
0.0000725
AC:
3
AN:
41352
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
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

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:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 1 deficiency Pathogenic:1Uncertain:2
Apr 19, 2021
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Aug 08, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 253 of the MCCC1 protein (p.Pro253Leu). This variant is present in population databases (rs202083272, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of 3 methylcrotonyl-CoA carboxylase deficiency (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 476399). 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 MCCC1 protein function with a positive predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Mar 03, 2020
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Jun 13, 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: MCCC1 c.758C>T (p.Pro253Leu) results in a non-conservative amino acid change located in the Carbamoyl-phosphate synthetase large subunit-like, ATP-binding domain( IPR005479) 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 1.2e-05 in 250760 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.758C>T has been observed in one individual affected with features of Methylcrotonyl-CoA Carboxylase Deficiency (internal data). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 476399). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Inborn genetic diseases Uncertain:1
Dec 19, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.758C>T (p.P253L) alteration is located in exon 7 (coding exon 7) of the MCCC1 gene. This alteration results from a C to T substitution at nucleotide position 758, causing the proline (P) at amino acid position 253 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.86
D;D;D;D;D
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Pathogenic
0.99
D;D;D;D;D
M_CAP
Uncertain
0.16
D
MetaRNN
Pathogenic
0.97
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.2
H;.;.;.;.
PhyloP100
9.5
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-9.6
D;D;.;.;D
REVEL
Pathogenic
0.86
Sift
Uncertain
0.0010
D;D;.;.;D
Sift4G
Pathogenic
0.0010
D;D;D;D;.
Polyphen
1.0
D;D;.;.;D
Vest4
0.98
MVP
0.99
MPC
0.62
ClinPred
1.0
D
GERP RS
5.6
Varity_R
0.96
gMVP
0.88
Mutation Taster
=24/76
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: rs202083272; hg19: chr3-182788790; COSMIC: COSV99659822; COSMIC: COSV99659822; API