rs1553854969

Positions:

• chr3-183041681-T-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP3_Strong PP5_Moderate

The NM_020166.5(MCCC1):​c.1153A>G​(p.Arg385Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,876 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. R385S) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MCCC1 NM_020166.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.55

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-183041679-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1930.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant 3-183041681-T-C is Pathogenic according to our data. Variant chr3-183041681-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 542952.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MCCC1	NM_020166.5	c.1153A>G	p.Arg385Gly	missense_variant	11/19	ENST00000265594.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MCCC1	ENST00000265594.9	c.1153A>G	p.Arg385Gly	missense_variant	11/19	1	NM_020166.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 1 deficiency Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 25, 2023

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. This variant disrupts the p.Arg385 amino acid residue in MCCC1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11170888, 14680978, 15868465, 22642865). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. ClinVar contains an entry for this variant (Variation ID: 542952). This variant has not been reported in the literature in individuals affected with MCCC1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 385 of the MCCC1 protein (p.Arg385Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;D;D;D;D
Eigen	Benign	0.18
Eigen_PC	Benign	0.11
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.6	H;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-6.8	D;D;.;.;D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0040	D;D;.;.;D
Sift4G	Uncertain	0.0040	D;D;D;D;.
Polyphen		0.75	P;B;.;.;B
Vest4		0.97
MutPred		0.92		Gain of catalytic residue at A384 (P = 0.0409);.;.;.;.;
MVP		0.98
MPC		0.35
ClinPred		0.99	D
GERP RS		1.3
Varity_R		0.98
gMVP		0.97

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

LitVar

Other links and lift over

dbSNP: rs1553854969; hg19: chr3-182759469;