NM_015506.3:c.178G>C

Variant names:

• chr1-45507452-G-C
• rs6662272
• NM_015506.3:c.178G>C

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 3P and 20B. PM1 PP2 BP4_Strong BP6_Very_Strong BA1

The NM_015506.3(MMACHC):​c.178G>C​(p.Asp60His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00479 in 1,614,128 control chromosomes in the GnomAD database, including 336 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. D60D) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.026 (171 hom., cov: 31)
  • Exomes 𝑓: 0.0026 (165 hom.)
• Consequence: MMACHC NM_015506.3 missense
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:11
• Conservation: PhyloP100: 7.51
• Publications: 6 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, Myriad Women’s Health, ClinGen, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Benign. The variant received -17 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_015506.3
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.003980756).
• BP6: Variant 1-45507452-G-C is Benign according to our data. Variant chr1-45507452-G-C is described in ClinVar as Benign. ClinVar VariationId is 138238.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0879 is higher than 0.05.

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.178G>C	p.Asp60His	missense	Exon 2 of 4	NP_056321.2	Q9Y4U1
	MMACHC	NM_001330540.2		c.7G>C	p.Asp3His	missense	Exon 2 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.178G>C	p.Asp60His	missense	Exon 2 of 4	ENSP00000383840.4	Q9Y4U1
	MMACHC	ENST00000616135.1	TSL:2	c.7G>C	p.Asp3His	missense	Exon 2 of 5	ENSP00000478859.1	A0A0C4DGU2
	MMACHC	ENST00000933807.1		c.82-760G>C		intron	N/A	ENSP00000603866.1

Frequencies

GnomAD3 genomes AF: 0.0259 AC: 3936 AN: 152126 Hom.: 171 Cov.: 31

Gnomad AFR AF: 0.0906

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00910

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00949

Gnomad NFE AF: 0.000309

Gnomad OTH AF: 0.0105

GnomAD2 exomes AF: 0.00637 AC: 1590 AN: 249514 AF XY: 0.00488

Gnomad AFR exome AF: 0.0907

Gnomad AMR exome AF: 0.00420

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000185

Gnomad OTH exome AF: 0.00248

GnomAD4 exome AF: 0.00260 AC: 3800 AN: 1461884 Hom.: 165 Cov.: 32 AF XY: 0.00222 AC XY: 1617 AN XY: 727244

African (AFR) AF: 0.0933 AC: 3123 AN: 33480

American (AMR) AF: 0.00483 AC: 216 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.000232 AC: 20 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00225 AC: 13 AN: 5768

European-Non Finnish (NFE) AF: 0.0000998 AC: 111 AN: 1112010

Other (OTH) AF: 0.00523 AC: 316 AN: 60396

GnomAD4 genome AF: 0.0258 AC: 3934 AN: 152244 Hom.: 171 Cov.: 31 AF XY: 0.0255 AC XY: 1895 AN XY: 74438

African (AFR) AF: 0.0903 AC: 3751 AN: 41520

American (AMR) AF: 0.00909 AC: 139 AN: 15296

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00680 AC: 2 AN: 294

European-Non Finnish (NFE) AF: 0.000294 AC: 20 AN: 68028

Other (OTH) AF: 0.0104 AC: 22 AN: 2114

Alfa AF: 0.00404 Hom.: 15

Bravo AF: 0.0292

ESP6500AA AF: 0.0837 AC: 346

ESP6500EA AF: 0.000355 AC: 3

ExAC AF: 0.00769 AC: 931

Asia WGS AF: 0.00577 AC: 20 AN: 3478

EpiCase AF: 0.000218

EpiControl AF: 0.000356

ClinVar

ClinVar submissions as Germline

Significance: Benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	5	not specified (5)
-	-	3	Cobalamin C disease (3)
-	-	2	not provided (2)
-	-	1	Disorders of Intracellular Cobalamin Metabolism (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D
MetaRNN	Benign	0.0040	T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Pathogenic	3.0	M
PhyloP100		7.5
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.77
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.011	D
Polyphen		1.0	D
Vest4		0.67
MVP		0.98
MPC		0.074
ClinPred		0.010	T
GERP RS		5.4
Varity_R		0.63
gMVP		0.66
Mutation Taster		=36/64	polymorphism (auto)

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: rs6662272; hg19: chr1-45973124;