chr3-183015492-G-GT

Variant names:

• chr3-183015492-G-GT
• rs1404350628
• NM_020166.5:c.2123dupA

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_020166.5(MCCC1):​c.2123dupA​(p.His708GlnfsTer8) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MCCC1 NM_020166.5 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 6.11
• Publications: 1 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: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• 3-methylcrotonyl-CoA carboxylase deficiency

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 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. Fraction of 0.0253 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-183015492-G-GT is Pathogenic according to our data. Variant chr3-183015492-G-GT is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 654061.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC1	NM_020166.5	MANE Select	c.2123dupA	p.His708GlnfsTer8	frameshift	Exon 19 of 19	NP_064551.3
	MCCC1	NM_001363880.1		c.1796dupA	p.His599GlnfsTer8	frameshift	Exon 18 of 18	NP_001350809.1	E9PHF7
	MCCC1	NM_001293273.2		c.1772dupA	p.His591GlnfsTer8	frameshift	Exon 17 of 17	NP_001280202.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MCCC1	ENST00000265594.9	TSL:1 MANE Select	c.2123dupA	p.His708GlnfsTer8	frameshift	Exon 19 of 19	ENSP00000265594.4	Q96RQ3
	MCCC1	ENST00000492597.5	TSL:1	c.1796dupA	p.His599GlnfsTer8	frameshift	Exon 18 of 18	ENSP00000419898.1	E9PHF7
	MCCC1	ENST00000497830.5	TSL:1	n.*1720dupA		non_coding_transcript_exon	Exon 17 of 17	ENSP00000420088.1	F2Z3E2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000113

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.1
Mutation Taster		=0/200	disease causing

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

Other links and lift over

dbSNP: rs1404350628; hg19: chr3-182733280;