3-183015348-C-T

Variant names:

• chr3-183015348-C-T
• rs894828851
• ENST00000497830.5:n.*1865G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_020166.5(MCCC1):​c.*90G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000779 in 1,424,664 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000085 (0 hom.)
• Consequence: MCCC1 NM_020166.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.971
• Publications: 0 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: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.9).
• BS1: Variant frequency is greater than expected in population eas. GnomAdExome4 allele frequency = 0.0000849 (108/1272450) while in subpopulation EAS AF = 0.00276 (107/38804). AF 95% confidence interval is 0.00233. There are 0 homozygotes in GnomAdExome4. There are 52 alleles in the male GnomAdExome4 subpopulation. Median coverage is 19. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MCCC1	NM_020166.5	c.*90G>A		3_prime_UTR_variant	Exon 19 of 19	ENST00000265594.9	NP_064551.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MCCC1	ENST00000265594.9	c.*90G>A		3_prime_UTR_variant	Exon 19 of 19	1	NM_020166.5	ENSP00000265594.4

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152214 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000577

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

GnomAD4 exome AF: 0.0000849 AC: 108 AN: 1272450 Hom.: 0 Cov.: 19 AF XY: 0.0000809 AC XY: 52 AN XY: 643006

African (AFR) AF: 0.00 AC: 0 AN: 29662

American (AMR) AF: 0.00 AC: 0 AN: 44450

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24946

East Asian (EAS) AF: 0.00276 AC: 107 AN: 38804

South Asian (SAS) AF: 0.00 AC: 0 AN: 81838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52264

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4952

European-Non Finnish (NFE) AF: 0.00000106 AC: 1 AN: 941314

Other (OTH) AF: 0.00 AC: 0 AN: 54220

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152214 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74362

African (AFR) AF: 0.00 AC: 0 AN: 41454

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000577 AC: 3 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68032

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

3-methylcrotonyl-CoA carboxylase 1 deficiency Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.90
CADD	Benign	0.11
DANN	Benign	0.27
PhyloP100		-0.97
Mutation Taster		=100/0	polymorphism

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: rs894828851; hg19: chr3-182733136;