rs398124434
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_052845.4(MMAB):c.568C>T(p.Arg190Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000989 in 1,415,906 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R190H) has been classified as Pathogenic.
Frequency
Consequence
NM_052845.4 missense
Scores
Clinical Significance
Conservation
Publications
- methylmalonic aciduria, cblB typeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, G2P, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 30
GnomAD2 exomes AF: 0.0000201 AC: 5AN: 248952 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.00000989 AC: 14AN: 1415906Hom.: 0 Cov.: 35 AF XY: 0.0000128 AC XY: 9AN XY: 704076 show subpopulations
GnomAD4 genome Cov.: 30
ClinVar
Submissions by phenotype
Methylmalonic aciduria, cblB type Pathogenic:6Other:1
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 190 of the MMAB protein (p.Arg190Cys). This variant is present in population databases (rs398124434, gnomAD 0.003%). This missense change has been observed in individuals with clinical features of methylmalonic aciduria cobalamin B type (PMID: 16410054, 24059531, 29039164). ClinVar contains an entry for this variant (Variation ID: 96244). 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 MMAB protein function. Experimental studies have shown that this missense change affects MMAB function (PMID: 19625202, 29197662). This variant disrupts the p.Arg190 amino acid residue in MMAB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16410054, 16439175, 19625202; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at