3-183034058-C-G

Variant names:

• chr3-183034058-C-G
• rs34749281
• NM_020166.5:c.1614G>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_020166.5(MCCC1):​c.1614G>C​(p.Ser538Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,458,342 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. S538S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MCCC1 NM_020166.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.890
• 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

LOC124906309 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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.1614G>C	p.Ser538Ser	synonymous	Exon 14 of 19	NP_064551.3
	MCCC1	NM_001363880.1		c.1287G>C	p.Ser429Ser	synonymous	Exon 13 of 18	NP_001350809.1
	MCCC1	NM_001293273.2		c.1263G>C	p.Ser421Ser	synonymous	Exon 12 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.1614G>C	p.Ser538Ser	synonymous	Exon 14 of 19	ENSP00000265594.4
	MCCC1	ENST00000492597.5	TSL:1	c.1287G>C	p.Ser429Ser	synonymous	Exon 13 of 18	ENSP00000419898.1
	MCCC1	ENST00000497830.5	TSL:1	n.*1211G>C		non_coding_transcript_exon	Exon 12 of 17	ENSP00000420088.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1458342 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 725800

African (AFR) AF: 0.00 AC: 0 AN: 33400

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39652

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86172

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53116

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5184

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109744

Other (OTH) AF: 0.00 AC: 0 AN: 60238

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.065	T
BayesDel_noAF	Benign	-0.33
CADD	Benign	8.5
DANN	Uncertain	0.98
DEOGEN2	Benign	0.056	T
FATHMM_MKL	Benign	0.61	D
LIST_S2	Benign	0.34	T
MetaRNN	Benign	0.17	T
PhyloP100		0.89
Sift4G	Benign	0.091	T
Vest4		0.40
MVP		0.74
GERP RS		2.7
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.35		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.32		Position offset: -6
DS_AL_spliceai		0.35		Position offset: 19

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

Other links and lift over

dbSNP: rs34749281; hg19: chr3-182751846;