Variant 1-45500378-CTA-C details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_015506.3(MMACHC):c.48_49del(p.Cys17SerfsTer16) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000657 in 152,308 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. L16L) has been classified as Likely benign.

Frequency

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

Consequence

MMACHC
NM_015506.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 4.95

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 109 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-45500378-CTA-C is Pathogenic according to our data. Variant chr1-45500378-CTA-C is described in ClinVar as [Pathogenic]. Clinvar id is 1076553.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MMACHC	NM_015506.3 linkuse as main transcript	c.48_49del	p.Cys17SerfsTer16	frameshift_variant	1/4	ENST00000401061.9
MMACHC	NM_001330540.2 linkuse as main transcript	c.-175_-174del		5_prime_UTR_variant	1/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MMACHC	ENST00000401061.9 linkuse as main transcript	c.48_49del	p.Cys17SerfsTer16	frameshift_variant	1/4	2	NM_015506.3	P1
MMACHC	ENST00000616135.1 linkuse as main transcript	c.-124_-123del		5_prime_UTR_variant	1/5	2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152190

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152308

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74488

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cobalamin C disease

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 26, 2020

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in MMACHC are known to be pathogenic (PMID: 16311595). This variant has not been reported in the literature in individuals with MMACHC-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change creates a premature translational stop signal (p.Cys17Serfs*16) in the MMACHC gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over