rs768272570

chr5-71656799-G-GT

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_022132.5(MCCC2):c.1635dup(p.Ser546Ter) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,614,050 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: MCCC2 NM_022132.5 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 0.0380

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 Likely_pathogenic. Variant got 7 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 6 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-71656799-G-GT is Pathogenic according to our data. Variant chr5-71656799-G-GT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 535825.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MCCC2	NM_022132.5	c.1635dup	p.Ser546Ter	frameshift_variant	17/17	ENST00000340941.11
MCCC2	NM_001363147.1	c.1521dup	p.Ser508Ter	frameshift_variant	16/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MCCC2	ENST00000340941.11	c.1635dup	p.Ser546Ter	frameshift_variant	17/17	1	NM_022132.5	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152188 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251442 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000103 AC: 15 AN: 1461862 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 727232

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

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: 0.0000117

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152188 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74354

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 2 deficiency Pathogenic:2 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Sep 03, 2023	This variant is present in population databases (rs768272570, gnomAD 0.006%). This sequence change creates a premature translational stop signal (p.Ser546*) in the MCCC2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 18 amino acid(s) of the MCCC2 protein. This premature translational stop signal has been observed in individual(s) with a positive newborn screening result for MCCC2-related disease (PMID: 27601257; Invitae). ClinVar contains an entry for this variant (Variation ID: 535825). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant disrupts a region of the MCCC2 protein in which other variant(s) (p.Thr556Ile) have been determined to be pathogenic (PMID: 25381946; Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Aug 25, 2021	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 09, 2023	- -

Methylcrotonyl-CoA carboxylase deficiency Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Sep 16, 2020

- -

Computational scores

Source: dbNSFP v4.3

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: rs768272570; hg19: chr5-70952626;