rs765822392
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM1PM2BP4_Strong
The NM_015506.3(MMACHC):c.800G>A(p.Arg267Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,613,804 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_015506.3 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
MMACHC | NM_015506.3 | c.800G>A | p.Arg267Gln | missense_variant | 4/4 | ENST00000401061.9 | NP_056321.2 | |
MMACHC | NM_001330540.2 | c.629G>A | p.Arg210Gln | missense_variant | 4/4 | NP_001317469.1 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
MMACHC | ENST00000401061.9 | c.800G>A | p.Arg267Gln | missense_variant | 4/4 | 2 | NM_015506.3 | ENSP00000383840 | P1 | |
MMACHC | ENST00000616135.1 | c.629G>A | p.Arg210Gln | missense_variant | 4/5 | 2 | ENSP00000478859 |
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 152078Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000683 AC: 17AN: 248864Hom.: 0 AF XY: 0.0000666 AC XY: 9AN XY: 135110
GnomAD4 exome AF: 0.0000356 AC: 52AN: 1461726Hom.: 0 Cov.: 32 AF XY: 0.0000385 AC XY: 28AN XY: 727166
GnomAD4 genome AF: 0.0000329 AC: 5AN: 152078Hom.: 0 Cov.: 32 AF XY: 0.0000539 AC XY: 4AN XY: 74270
ClinVar
Submissions by phenotype
Cobalamin C disease Uncertain:5
Uncertain significance, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Apr 11, 2023 | - - |
Uncertain significance, criteria provided, single submitter | clinical testing | Revvity Omics, Revvity | Jul 05, 2021 | - - |
Uncertain significance, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Aug 30, 2021 | This sequence change replaces arginine with glutamine at codon 267 of the MMACHC protein (p.Arg267Gln). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and glutamine. This variant is present in population databases (rs765822392, ExAC 0.02%). This missense change has been observed in individual(s) with methylmalonic aciduria and homocystinuria (PMID: 16311595, 19370762, 24126030). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 378150). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. - |
Uncertain significance, criteria provided, single submitter | clinical testing | Neuberg Centre For Genomic Medicine, NCGM | - | The observed missense variant c.800G>A(p.Arg267Gln) in MMACHC gene has been reported previously in individuals with cblC deficiency who also harbored c.271dupA but it is not known whether these variants occurred in cis/trans chromosomes (Gizicki et al., 2014). Also, this variant is described as a benign and possibly benign variant (Lerner-Ellis JP, et al., 2009). The c.800G>A variant has 0.01% allele frequency in gnomAD Exomes. This variant has been reported to the ClinVar database as Uncertain Significance. The amino acid Arginine at position 267 is changed to a Glutamine changing protein sequence and it might alter its composition and physico-chemical properties.The amino acid change p.Arg267Gln in MMACHC is predicted as conserved by GERP++. For these reasons, this variant has been classified as Uncertain Significance. - |
Uncertain significance, criteria provided, single submitter | clinical testing | Myriad Genetics, Inc. | Oct 20, 2021 | NM_015506.2(MMACHC):c.800G>A(R267Q) is a missense variant classified as a variant of uncertain significance in the context of methylmalonic aciduria and homocystinuria, cblC type. R267Q has been observed in cases with relevant disease (PMID: 16311595, 24126030). Functional assessments of this variant are not available in the literature. R267Q has been observed in population frequency databases (gnomAD: SAS 0.02%). In summary, there is insufficient evidence to classify NM_015506.2(MMACHC):c.800G>A(R267Q) as pathogenic or benign. Please note: this variant was assessed in the context of healthy population screening. - |
not specified Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Jan 11, 2024 | Variant summary: MMACHC c.800G>A (p.Arg267Gln) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 6.8e-05 in 248864 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in MMACHC causing Methylmalonic Acidemia With Homocystinuria (6.8e-05 vs 0.0032), allowing no conclusion about variant significance. c.800G>A has been reported in the literature in individuals affected with Cobalamin C Disease (Methylmalonic Aciduria With Homocystinuria), however the majority of these reports identified the variant as part of a complex allele with c.271dupA (p.R91Kfs) (e.g., Lerner-Ellis_2006, Lerner-Ellis_2009, Koutmos_2011, Gizicki_2014, Stranneheim_2021, Kacpura_2022). These reports therefore do not provide unequivocal conclusions about association of the variant with Methylmalonic Acidemia With Homocystinuria. 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: 24126030, 35156754, 19370762, 16311595, 33726816, 21697092). ClinVar contains an entry for this variant (Variation ID: 378150). Based on the evidence outlined above, the variant was classified as uncertain significance. - |
Inborn genetic diseases Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Ambry Genetics | Sep 12, 2022 | The c.800G>A (p.R267Q) alteration is located in exon 4 (coding exon 4) of the MMACHC gene. This alteration results from a G to A substitution at nucleotide position 800, causing the arginine (R) at amino acid position 267 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. - |
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | GeneDx | Apr 19, 2021 | Also observed in an individual with cblC deficiency who also harbored c.271dupA but it is not known whether these variants occurred on the same (in cis) or opposite (in trans) chromosomes (Gizicki et al., 2014); Described as a benign and possibly benign variant (Lerner-Ellis et al., 2009; Koutmos et al., 2011); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 21697092, 24126030, 19370762, 16311595) - |
Methylmalonic acidemia with homocystinuria cblC Benign:1
Likely benign, no assertion criteria provided | clinical testing | Natera, Inc. | Sep 16, 2020 | - - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at