rs201041864

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP5

The NM_020166.5(MCCC1):​c.872C>T​(p.Ala291Val) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000155 in 1,598,522 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. A291E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00016 ( 0 hom. )

Consequence

MCCC1
NM_020166.5 missense, splice_region

Scores

8
9
2
Splicing: ADA: 0.001581
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5U:1

Conservation

PhyloP100: 2.82

Publications

7 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: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_020166.5
PP5
Variant 3-183057312-G-A is Pathogenic according to our data. Variant chr3-183057312-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 476401.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MCCC1NM_020166.5 linkc.872C>T p.Ala291Val missense_variant, splice_region_variant Exon 8 of 19 ENST00000265594.9 NP_064551.3 Q96RQ3A0A0S2Z693

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MCCC1ENST00000265594.9 linkc.872C>T p.Ala291Val missense_variant, splice_region_variant Exon 8 of 19 1 NM_020166.5 ENSP00000265594.4 Q96RQ3

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152146
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.000176
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000139
AC:
32
AN:
230448
AF XY:
0.000129
show subpopulations
Gnomad AFR exome
AF:
0.0000681
Gnomad AMR exome
AF:
0.000334
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000177
Gnomad OTH exome
AF:
0.000173
GnomAD4 exome
AF:
0.000158
AC:
229
AN:
1446376
Hom.:
0
Cov.:
30
AF XY:
0.000134
AC XY:
96
AN XY:
718098
show subpopulations
African (AFR)
AF:
0.0000301
AC:
1
AN:
33264
American (AMR)
AF:
0.000323
AC:
14
AN:
43338
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25776
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39514
South Asian (SAS)
AF:
0.0000238
AC:
2
AN:
83972
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52766
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.000180
AC:
198
AN:
1102210
Other (OTH)
AF:
0.000234
AC:
14
AN:
59772
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.457
Heterozygous variant carriers
0
10
21
31
42
52
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:
0.000118
AC:
18
AN:
152146
Hom.:
0
Cov.:
32
AF XY:
0.000108
AC XY:
8
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41424
American (AMR)
AF:
0.000262
AC:
4
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000176
AC:
12
AN:
68018
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
1
2
3
4
5
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:
0.000107
Hom.:
0
Bravo
AF:
0.000166
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.000115
AC:
14

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:5Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

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

- -

Dec 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 291 of the MCCC1 protein (p.Ala291Val). This variant is present in population databases (rs201041864, gnomAD 0.03%). This missense change has been observed in individuals with biochemical testing consistent with 3-MCC deficiency (PMID: 16010683, 22642865, 30626930; internal data). ClinVar contains an entry for this variant (Variation ID: 476401). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects MCCC1 function (PMID: 16010683). For these reasons, this variant has been classified as Pathogenic. -

Jun 12, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1Uncertain:1
Jul 24, 2023
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Expression studies found that this variant is associated with significantly reduced MCC activity compared to wild-type (Dantas MF et al., 2005); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30626930, 35281663, 31737040, 16010683, 31730530, 22642865) -

Nov 30, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Methylcrotonyl-CoA carboxylase deficiency Pathogenic:1
Nov 01, 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.872C>T (p.Ala291Val) 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. Five of five in-silico tools predict a damaging effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00014 in 230448 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in MCCC1 causing Methylcrotonyl-CoA Carboxylase Deficiency (0.00014 vs 0.0042), allowing no conclusion about variant significance. c.872C>T has been reported in the literature in multiple individuals affected with Methylcrotonyl-CoA Carboxylase Deficiency (Dantas_2005, Shepard_2015, Wang_2019, Navarrete_2019, Martn-Rivada_2022). These data indicate that the variant is likely to be associated with disease. The variant was examined via transfection assays using MCCC1 deficient cells, and the variant was found with 26% enzymatic activity compared to wild-type (Dantas_2005). The following publications have been ascertained in the context of this evaluation (PMID: 25356967, 30626930, 16010683, 31730530, 35281663). Three submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified this variant as uncertain significance, likely pathogenic and 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
Uncertain
0.45
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Pathogenic
0.24
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.81
D;D;D;D;D
Eigen
Uncertain
0.38
Eigen_PC
Uncertain
0.31
FATHMM_MKL
Uncertain
0.85
D
LIST_S2
Pathogenic
0.99
D;D;D;D;D
M_CAP
Pathogenic
0.50
D
MetaRNN
Uncertain
0.72
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.8
H;.;.;.;.
PhyloP100
2.8
PrimateAI
Benign
0.36
T
PROVEAN
Uncertain
-3.3
D;D;.;.;D
REVEL
Pathogenic
0.83
Sift
Uncertain
0.015
D;D;.;.;D
Sift4G
Uncertain
0.029
D;D;D;D;.
Polyphen
0.98
D;B;.;.;D
Vest4
0.77
MVP
0.97
MPC
0.59
ClinPred
0.90
D
GERP RS
1.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.66
gMVP
0.87
Mutation Taster
=4/96
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0016
dbscSNV1_RF
Benign
0.26
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: rs201041864; hg19: chr3-182775100; API