rs727504009
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5
The NM_022132.5(MCCC2):c.478G>A(p.Ala160Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,614,018 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. A160G) has been classified as Uncertain significance.
Frequency
Consequence
NM_022132.5 missense
Scores
Clinical Significance
Conservation
Publications
- 3-methylcrotonyl-CoA carboxylase 2 deficiencyInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- 3-methylcrotonyl-CoA carboxylase deficiencyInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
MCCC2 | NM_022132.5 | c.478G>A | p.Ala160Thr | missense_variant | Exon 5 of 17 | ENST00000340941.11 | NP_071415.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152152Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000795 AC: 2AN: 251476 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000752 AC: 11AN: 1461866Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152152Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74330 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
3-methylcrotonyl-CoA carboxylase 2 deficiency Pathogenic:1Uncertain:1
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This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 160 of the MCCC2 protein (p.Ala160Thr). This variant is present in population databases (rs727504009, gnomAD 0.003%). This missense change has been observed in individual(s) with 3-methylcrotonyl-CoA carboxylase (3MCC) deficiency (PMID: 32778825; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 167277). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MCCC2 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
MCCC2-related disorder Uncertain:1
The MCCC2 c.478G>A variant is predicted to result in the amino acid substitution p.Ala160Thr. This variant was reported in a newborn screening for inborn errors of metabolism; however, clinical information was not provided (Table S5, Adhikari et al. 2020. PubMed ID: 32778825). This variant is reported in 0.0029% of alleles in individuals of Latino descent in gnomAD. A different missense variant (c.479C>A, Ala160Asp) has been reported, along with another variant of uncertain significance, in a patient with elevated C5-OH by newborn screening suggestive of 3-methylcrotonyl-CoA carboxylase deficiency with mild elevation of 3-methylcrotonylglycine and normal 3-hydroxyisovaleric acid (Cheng et al. 2023. PubMed ID: 36822454). Although we suspect this variant may be pathogenic, at this time, the clinical significance of the c.478G>A variant is uncertain due to the absence of conclusive functional and genetic evidence. -
not provided Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at