NM_020166.5:c.2079delA

Variant names:

• chr3-183015536-CT-C
• rs119103217
• NM_020166.5:c.2079delA

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_020166.5(MCCC1):​c.2079delA​(p.Val694fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,826 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. T693T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MCCC1 NM_020166.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: -4.19
• Publications: 3 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-183015536-CT-C is Pathogenic according to our data. Variant chr3-183015536-CT-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1934.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020166.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC1	NM_020166.5	MANE Select	c.2079delA	p.Val694fs	frameshift	Exon 19 of 19	NP_064551.3
	MCCC1	NM_001363880.1		c.1752delA	p.Val585fs	frameshift	Exon 18 of 18	NP_001350809.1
	MCCC1	NM_001293273.2		c.1728delA	p.Val577fs	frameshift	Exon 17 of 17	NP_001280202.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC1	ENST00000265594.9	TSL:1 MANE Select	c.2079delA	p.Val694fs	frameshift	Exon 19 of 19	ENSP00000265594.4
	MCCC1	ENST00000492597.5	TSL:1	c.1752delA	p.Val585fs	frameshift	Exon 18 of 18	ENSP00000419898.1
	MCCC1	ENST00000497830.5	TSL:1	n.*1676delA		non_coding_transcript_exon	Exon 17 of 17	ENSP00000420088.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000160 AC: 4 AN: 249234 AF XY: 0.0000222

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000993

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000269

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461826 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727216

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111956

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	3-methylcrotonyl-CoA carboxylase 1 deficiency (4)
2	-	-	not provided (2)
1	-	-	MCCC1-related disorder (1)
1	-	-	Methylcrotonyl-CoA carboxylase deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-4.2
Mutation Taster		=8/192	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs119103217; hg19: chr3-182733324;