dbSNP rs115078899: MCCC2:c.282-7G>A (chr5-71599652-G-A) – ACMG Classification: Benign (-16 pts)

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS2

The NM_022132.5(MCCC2):c.282-7G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000753 in 1,607,362 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0037 ( 2 hom., cov: 32)

Exomes 𝑓: 0.00044 ( 3 hom. )

Consequence

MCCC2
NM_022132.5 splice_region, intron

Scores

Splicing: ADA: 0.00009839

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 0.0440

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -16 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.79).

BP6

Variant 5-71599652-G-A is Benign according to our data. Variant chr5-71599652-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 261559.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MCCC2	NM_022132.5 link	c.282-7G>A		splice_region_variant, intron_variant	Intron 3 of 16	ENST00000340941.11	NP_071415.1	Q9HCC0-1A0A140VK29

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MCCC2	ENST00000340941.11 link	c.282-7G>A		splice_region_variant, intron_variant	Intron 3 of 16	1	NM_022132.5	ENSP00000343657.6		Q9HCC0-1

Frequencies

GnomAD3 genomes

AF:

0.00373

AC:

566

AN:

151902

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0126

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00184

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:

0.000177

Gnomad OTH

AF:

0.00239

GnomAD3 exomes

AF:

0.00101

AC:

253

AN:

251392

Hom.:

AF XY:

0.000677

AC XY:

AN XY:

135876

show subpopulations

Gnomad AFR exome

AF:

0.0128

Gnomad AMR exome

AF:

0.000665

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000149

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000443

AC:

644

AN:

1455342

Hom.:

Cov.:

AF XY:

0.000382

AC XY:

277

AN XY:

724514

show subpopulations

Gnomad4 AFR exome

AF:

0.0119

Gnomad4 AMR exome

AF:

0.000805

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000697

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000111

Gnomad4 OTH exome

AF:

0.00118

GnomAD4 genome

AF:

0.00373

AC:

567

AN:

152020

Hom.:

Cov.:

AF XY:

0.00363

AC XY:

270

AN XY:

74306

show subpopulations

Gnomad4 AFR

AF:

0.0126

Gnomad4 AMR

AF:

0.00183

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000177

Gnomad4 OTH

AF:

0.00237

Alfa

AF:

0.00181

Hom.:

Bravo

AF:

0.00410

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.000415

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:3

Mar 02, 2017

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 01, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MCCC2 c.282-7G>A alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing, however, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.001 in 251392 control chromosomes (gnomAD), predominantly at a frequency of 0.013 within the African or African-American subpopulation in the gnomAD database, including 3 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 3-fold of the estimated maximal expected allele frequency for a pathogenic variant in MCCC2 causing Methylcrotonyl-CoA Carboxylase Deficiency phenotype (0.0042), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.282-7G>A in individuals affected with Methylcrotonyl-CoA Carboxylase Deficiency and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -

not provided

Benign:1

Breakthrough Genomics, Breakthrough Genomics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

3-methylcrotonyl-CoA carboxylase 2 deficiency

Benign:1

Jan 22, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.79

CADD

Benign

2.5

DANN

Benign

0.39

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.000098

dbscSNV1_RF

Benign

0.022

SpliceAI score (max)

0.060

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over