3-183086767-C-T
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5
The NM_020166.5(MCCC1):c.295G>A(p.Gly99Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,613,918 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G99R) has been classified as Uncertain significance.
Frequency
Consequence
NM_020166.5 missense
Scores
Clinical Significance
Conservation
Publications
- 3-methylcrotonyl-CoA carboxylase 1 deficiencyInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- 3-methylcrotonyl-CoA carboxylase deficiencyInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MCCC1 | NM_020166.5 | c.295G>A | p.Gly99Ser | missense_variant | Exon 4 of 19 | ENST00000265594.9 | NP_064551.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MCCC1 | ENST00000265594.9 | c.295G>A | p.Gly99Ser | missense_variant | Exon 4 of 19 | 1 | NM_020166.5 | ENSP00000265594.4 |
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152132Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251214 AF XY: 0.0000295 show subpopulations
GnomAD4 exome AF: 0.0000253 AC: 37AN: 1461786Hom.: 0 Cov.: 31 AF XY: 0.0000206 AC XY: 15AN XY: 727180 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152132Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74310 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
3-methylcrotonyl-CoA carboxylase 1 deficiency Pathogenic:1Uncertain:1
In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MCCC1 protein function. ClinVar contains an entry for this variant (Variation ID: 656280). This missense change has been observed in individual(s) with 3 Methylcrotonyl-CoA carboxylase deficiency (PMID: 25190158, 31730530; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs375244642, gnomAD 0.02%). This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 99 of the MCCC1 protein (p.Gly99Ser).
not specified Uncertain:1
Variant summary: MCCC1 c.295G>A (p.Gly99Ser) results in a non-conservative amino acid change located in the biotin carboxylase-like, N-terminal domain (IPR005481) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 251214 control chromosomes. c.295G>A has been reported in the literature in individuals identified through newborn screening programs as affected with Methylcrotonyl-CoA Carboxylase Deficiency, including at least one case where it was found in trans with a pathogenic variant (e.g. Ye_2014, Wang_2019, Yang_2019, Cheng_2023). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 36822454, 31730530, 30838026, 25190158). ClinVar contains an entry for this variant (Variation ID: 656280). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at