rs754460336

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3_ModeratePP5_Very_Strong

The NM_020166.5(MCCC1):​c.196C>T​(p.Arg66Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000291 in 1,614,002 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R66H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

MCCC1
NM_020166.5 missense

Scores

13
4
2

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 5.40

Publications

1 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: Pathogenic. The variant received 10 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.899
PP5
Variant 3-183092486-G-A is Pathogenic according to our data. Variant chr3-183092486-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 542949.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC1NM_020166.5 linkc.196C>T p.Arg66Cys missense_variant Exon 3 of 19 ENST00000265594.9 NP_064551.3 Q96RQ3A0A0S2Z693

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC1ENST00000265594.9 linkc.196C>T p.Arg66Cys missense_variant Exon 3 of 19 1 NM_020166.5 ENSP00000265594.4 Q96RQ3

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152142
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000328
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000636
AC:
16
AN:
251472
AF XY:
0.0000515
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000217
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000280
AC:
41
AN:
1461860
Hom.:
0
Cov.:
32
AF XY:
0.0000303
AC XY:
22
AN XY:
727226
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000126
AC:
5
AN:
39698
South Asian (SAS)
AF:
0.000197
AC:
17
AN:
86256
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:
0.0000108
AC:
12
AN:
1111982
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
4
7
11
14
18
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:
0.0000394
AC:
6
AN:
152142
Hom.:
0
Cov.:
32
AF XY:
0.0000673
AC XY:
5
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.000328
AC:
5
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10594
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.417
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000302
ExAC
AF:
0.0000494
AC:
6

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 1 deficiency Pathogenic:3
May 29, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 22, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 66 of the MCCC1 protein (p.Arg66Cys). This variant is present in population databases (rs754460336, gnomAD 0.02%). This missense change has been observed in individual(s) with MCCC1-related conditions (PMID: 36822454; 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: 542949). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MCCC1 protein function. 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. -

Dec 22, 2023
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Methylcrotonyl-CoA carboxylase deficiency Pathogenic:1
Mar 22, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MCCC1 c.196C>T (p.Arg66Cys) results in a non-conservative amino acid change located in the Biotin carboxylase-like, N-terminal domain (IPR005481) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.4e-05 in 251472 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in MCCC1 causing Methylcrotonyl-CoA Carboxylase Deficiency (6.4e-05 vs 0.0042), allowing no conclusion about variant significance. c.196C>T has been reported in the literature in individuals affected with Methylcrotonyl-CoA Carboxylase Deficiency (Men_2023, Cheng_2023). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One submitter has provided a clinical-significance assessment for this variant to ClinVar after 2014 without evidence for independent evaluation, and classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.52
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.89
D;D
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Uncertain
0.24
D
MetaRNN
Pathogenic
0.90
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.5
H;.
PhyloP100
5.4
PrimateAI
Uncertain
0.61
T
PROVEAN
Pathogenic
-6.7
D;.
REVEL
Pathogenic
0.91
Sift
Uncertain
0.0010
D;.
Sift4G
Pathogenic
0.0010
D;D
Polyphen
1.0
D;.
Vest4
0.81
MutPred
0.73
Loss of MoRF binding (P = 0.0235);.;
MVP
0.99
MPC
0.68
ClinPred
0.95
D
GERP RS
5.0
Varity_R
0.74
gMVP
0.83
Mutation Taster
=73/27
disease causing (ClinVar)

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: rs754460336; hg19: chr3-182810274; COSMIC: COSV99660015; API