rs1029096863

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_172250.3(MMAA):​c.586C>T​(p.Arg196*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000242 in 1,613,664 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000026 ( 0 hom. )

Consequence

MMAA
NM_172250.3 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 5.67
Variant links:
Genes affected
MMAA (HGNC:18871): (metabolism of cobalamin associated A) The protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase. Defects in this gene are a cause of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 4-145646009-C-T is Pathogenic according to our data. Variant chr4-145646009-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 466217.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-145646009-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
MMAANM_172250.3 linkc.586C>T p.Arg196* stop_gained 4/7 ENST00000649156.2 NP_758454.1 Q8IVH4
MMAANM_001375644.1 linkc.586C>T p.Arg196* stop_gained 4/7 NP_001362573.1
MMAAXM_011531684.4 linkc.586C>T p.Arg196* stop_gained 4/7 XP_011529986.1 Q8IVH4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
MMAAENST00000649156.2 linkc.586C>T p.Arg196* stop_gained 4/7 NM_172250.3 ENSP00000497008.1 Q8IVH4

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151948
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000796
AC:
2
AN:
251370
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135854
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000260
AC:
38
AN:
1461716
Hom.:
0
Cov.:
31
AF XY:
0.0000248
AC XY:
18
AN XY:
727170
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000315
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151948
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74210
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblA type Pathogenic:7
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Sep 16, 2020- -
Pathogenic, criteria provided, single submitterclinical testingCentre for Inherited Metabolic Diseases, Karolinska University HospitalApr 07, 2021- -
Pathogenic, criteria provided, single submitterresearchCenter for Genomic Medicine, King Faisal Specialist Hospital and Research CenterMar 17, 2024- -
Pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsDec 20, 2023- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 09, 2023For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 466217). This premature translational stop signal has been observed in individuals with methylmalonic acidemia (PMID: 21545677, 23711287, 25636100; Invitae). This variant is present in population databases (no rsID available, gnomAD 0.002%). This sequence change creates a premature translational stop signal (p.Arg196*) in the MMAA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MMAA are known to be pathogenic (PMID: 15523652, 15781192). -
Pathogenic, no assertion criteria providedclinical testingBiochemical Molecular Genetic Laboratory, King Abdulaziz Medical CityFeb 05, 2020- -
Pathogenic, no assertion criteria providedclinical testingCounsylSep 01, 2017- -
not provided Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingGeneDxSep 01, 2023Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 27629047, 29996803, 34670123, 25567501, 23711287, 25636100, 16247646, 31622506, 33726816, 32754920, 33453710, 21545677) -
Methylmalonic acidemia Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpApr 08, 2019Variant summary: MMAA c.586C>T (p.Arg196X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 8.1e-06 in 246142 control chromosomes (gnomAD). c.586C>T has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Methylmalonic Acidemia (Plessl_2017, Sun_2015, Lubrano_2013, Nizon_2013). These data indicate that the variant is very likely to be associated with disease. At least one publication evaluated patient derived fibroblasts and demonstrated severely decreased enzyme activity values in homozygotes (Plessl 2017). Two ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.61
D
BayesDel_noAF
Pathogenic
0.65
CADD
Pathogenic
37
DANN
Uncertain
1.0
Eigen
Pathogenic
0.89
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Uncertain
0.96
D
Vest4
0.96
GERP RS
4.6

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1029096863; hg19: chr4-146567161; COSMIC: COSV99849569; COSMIC: COSV99849569; API