rs119103223

chr5-71632185-G-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_022132.5(MCCC2):c.803G>C(p.Arg268Thr) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,704 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R268G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MCCC2 NM_022132.5 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 5.86

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a domain CoA carboxyltransferase N-terminal (size 257) in uniprot entity MCCB_HUMAN there are 45 pathogenic changes around while only 2 benign (96%) in NM_022132.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-71632185-G-C is Pathogenic according to our data. Variant chr5-71632185-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 1924.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MCCC2	NM_022132.5	c.803G>C	p.Arg268Thr	missense_variant, splice_region_variant	8/17	ENST00000340941.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MCCC2	ENST00000340941.11	c.803G>C	p.Arg268Thr	missense_variant, splice_region_variant	8/17	1	NM_022132.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461704 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727164

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 2 deficiency Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Feb 11, 2023	Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change results in activation of a cryptic splice site, deletes the last 19bp of exon 8 and introduces a premature termination codon (PMID: 16010683). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 268 of the MCCC2 protein (p.Arg268Thr). RNA analysis indicates that this missense change induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with 3 methylcrotonyl-CoA carboxylase deficiency (PMID: 11406611, 16835865). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 1924). -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jun 01, 2001	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Mar 01, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
Cadd	Pathogenic	37
Dann	Uncertain	0.98
DEOGEN2	Benign	0.082	T;D;.;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.94	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	A;A;A
PrimateAI	Uncertain	0.68	T
Sift4G	Benign	0.11	T;T;T;T
Polyphen		0.64, 0.76	.;P;P;.
Vest4		0.68
MutPred		0.86		.;Loss of stability (P = 0.0595);Loss of stability (P = 0.0595);.;
MVP		0.95
MPC		0.46
ClinPred		0.99	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.72
gMVP		0.66

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.73		Position offset: -19
DS_DL_spliceai		0.92		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs119103223; hg19: chr5-70928012;