MCCC2 p.Arg268Thr

Variant names:

• chr5-71632185-G-C
• rs119103223
• NM_022132.5:c.803G>C
• MCCC2 p.Arg268Thr

Your query was ambiguous. Multiple possible variants found:

• chr5-71632185-G-C
• chr5-71632185-GA-CT
• chr5-71632185-GA-CC
• chr5-71632185-GA-CG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PS3 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 (★★). ClinVar reports functional evidence for this variant: "SCV004293740: 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). RNA analysis indicates that this missense change induces altered splicing and may result in an absent or disrupted protein product.". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R268K) 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
• Publications: 7 publications found

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]

MCCC2 Gene-Disease associations (from GenCC):

• 3-methylcrotonyl-CoA carboxylase 2 deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• 3-methylcrotonyl-CoA carboxylase deficiency

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV004293740: 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). RNA analysis indicates that this missense change induces altered splicing and may result in an absent or disrupted protein product.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious 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 VariationId is 1924.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022132.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC2	NM_022132.5	MANE Select	c.803G>C	p.Arg268Thr	missense splice_region	Exon 8 of 17	NP_071415.1	A0A140VK29
	MCCC2	NM_001363147.1		c.689G>C	p.Arg230Thr	missense splice_region	Exon 7 of 16	NP_001350076.1	Q9HCC0-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC2	ENST00000340941.11	TSL:1 MANE Select	c.803G>C	p.Arg268Thr	missense splice_region	Exon 8 of 17	ENSP00000343657.6	Q9HCC0-1
	MCCC2	ENST00000509358.7	TSL:1	c.803G>C	p.Arg268Thr	missense splice_region	Exon 8 of 12	ENSP00000420994.3	D6RDF7
	MCCC2	ENST00000629193.3	TSL:1	c.689G>C	p.Arg230Thr	missense splice_region	Exon 7 of 10	ENSP00000486535.2	A0A0D9SFE9

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

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111852

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	3-methylcrotonyl-CoA carboxylase 2 deficiency (2)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

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
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	1.4	L
PhyloP100		5.9
PrimateAI	Uncertain	0.68	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D
Sift4G	Benign	0.11	T
PromoterAI		0.0033	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.72
gMVP		0.66
Mutation Taster		=14/86	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
Splicevardb		2.0
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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs119103223;

hg19: chr5-70928012;