rs773059864

Variant names:

• chr12-109561067-C-G
• rs773059864
• NM_052845.4:c.557G>C

Your query was ambiguous. Multiple possible variants found:

• chr12-109561067-C-G
• chr12-109561067-C-T
• chr12-109561067-C-A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_052845.4(MMAB):​c.557G>C​(p.Arg186Pro) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,458,936 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. R186Q) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MMAB NM_052845.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 5.67
• Publications: 0 publications found

Genes affected

MMAB (HGNC:19331): (metabolism of cobalamin associated B) This gene encodes a protein that catalyzes the final step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12-containing coenzyme for methylmalonyl-CoA mutase. Mutations in the gene are the cause of vitamin B12-dependent methylmalonic aciduria linked to the cblB complementation group. Alternatively spliced transcript variants have been found. [provided by RefSeq, Apr 2011]

MMAB Gene-Disease associations (from GenCC):

• methylmalonic acidemia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• methylmalonic aciduria, cblB type

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Myriad Women’s Health, G2P

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_052845.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-109561067-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 552212.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant 12-109561067-C-G is Pathogenic according to our data. Variant chr12-109561067-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2954625.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052845.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMAB	NM_052845.4	MANE Select	c.557G>C	p.Arg186Pro	missense	Exon 7 of 9	NP_443077.1	Q96EY8
	MMAB	NR_038118.2		n.668G>C		non_coding_transcript_exon	Exon 8 of 10

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMAB	ENST00000545712.7	TSL:1 MANE Select	c.557G>C	p.Arg186Pro	missense	Exon 7 of 9	ENSP00000445920.1	Q96EY8
	MMAB	ENST00000878519.1		c.620G>C	p.Arg207Pro	missense	Exon 8 of 10	ENSP00000548578.1
	MMAB	ENST00000878520.1		c.557G>C	p.Arg186Pro	missense	Exon 7 of 8	ENSP00000548579.1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1458936 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 726002

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.0000198 AC: 1 AN: 50520

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111990

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome Cov.: 30

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Methylmalonic aciduria, cblB type (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	4.8	H
PhyloP100		5.7
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-6.2	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.94		Loss of MoRF binding (P = 5e-04)
MVP		1.0
MPC		0.97
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.99
gMVP		0.99
Mutation Taster		=16/84	disease causing

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

Other links and lift over

dbSNP: rs773059864; hg19: chr12-109998872;