rs1553162910

Variant names:

• chr1-45508833-G-A
• rs1553162910
• NM_015506.3:c.467G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_015506.3(MMACHC):​c.467G>A​(p.Gly156Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,850 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. G156S) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MMACHC NM_015506.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 9.36
• Publications: 3 publications found

Genes affected

MMACHC (HGNC:24525): (metabolism of cobalamin associated C) The exact function of the protein encoded by this gene is not known, however, its C-terminal region shows similarity to TonB, a bacterial protein involved in energy transduction for cobalamin (vitamin B12) uptake. Hence, it is postulated that this protein may have a role in the binding and intracellular trafficking of cobalamin. Mutations in this gene are associated with methylmalonic aciduria and homocystinuria type cblC. [provided by RefSeq, Oct 2009]

MMACHC Gene-Disease associations (from GenCC):

• methylmalonic aciduria and homocystinuria type cblC

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

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_015506.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-45508832-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1495958.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 28 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: -1.0759 (below the threshold of 3.09). Trascript score misZ: -0.13772 (below the threshold of 3.09). GenCC associations: The gene is linked to methylmalonic aciduria and homocystinuria type cblC.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 1-45508833-G-A is Pathogenic according to our data. Variant chr1-45508833-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 554696.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015506.3. 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
	MMACHC	NM_015506.3	MANE Select	c.467G>A	p.Gly156Asp	missense	Exon 4 of 4	NP_056321.2	Q9Y4U1
	MMACHC	NM_001330540.2		c.296G>A	p.Gly99Asp	missense	Exon 4 of 4	NP_001317469.1	A0A0C4DGU2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MMACHC	ENST00000401061.9	TSL:2 MANE Select	c.467G>A	p.Gly156Asp	missense	Exon 4 of 4	ENSP00000383840.4	Q9Y4U1
	MMACHC	ENST00000616135.1	TSL:2	c.296G>A	p.Gly99Asp	missense	Exon 4 of 5	ENSP00000478859.1	A0A0C4DGU2
	MMACHC	ENST00000933807.1		c.272G>A	p.Gly91Asp	missense	Exon 3 of 3	ENSP00000603866.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461850 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727224

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

American (AMR) AF: 0.0000447 AC: 2 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	1	-	Cobalamin C disease (3)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.79	T
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		9.4
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-6.4	D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.057	T
Polyphen		0.95	P
Vest4		0.97
MutPred		0.94		Loss of MoRF binding (P = 0.0721)
MVP		0.97
MPC		0.073
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.94
gMVP		0.99
Mutation Taster		=4/96	disease causing (ClinVar)

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: rs1553162910; hg19: chr1-45974505;