rs397509364

Positions:

• chr2-149571078-TACTC-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_015702.3(MMADHC):​c.696+3_696+6del variant causes a splice donor 5th base, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MMADHC NM_015702.3 splice_donor_5th_base, intron
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.79

Genes affected

MMADHC (HGNC:25221): (metabolism of cobalamin associated D) This gene encodes a mitochondrial protein that is involved in an early step of vitamin B12 metabolism. Vitamin B12 (cobalamin) is essential for normal development and survival in humans. Mutations in this gene cause methylmalonic aciduria and homocystinuria type cblD (MMADHC), a disorder of cobalamin metabolism that is characterized by decreased levels of the coenzymes adenosylcobalamin and methylcobalamin. Pseudogenes have been identified on chromosomes 11 and X.[provided by RefSeq, Nov 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-149571078-TACTC-T is Pathogenic according to our data. Variant chr2-149571078-TACTC-T is described in ClinVar as [Pathogenic]. Clinvar id is 769.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MMADHC	NM_015702.3	c.696+3_696+6del		splice_donor_5th_base_variant, intron_variant		ENST00000303319.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MMADHC	ENST00000303319.10	c.696+3_696+6del		splice_donor_5th_base_variant, intron_variant		1	NM_015702.3	P1
MMADHC	ENST00000422782.2	c.798+3_798+6del		splice_donor_5th_base_variant, intron_variant		5
MMADHC	ENST00000428879.5	c.696+3_696+6del		splice_donor_5th_base_variant, intron_variant		2		P1

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Methylmalonic aciduria and homocystinuria type cblD Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Apr 03, 2008

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.85		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.85		Position offset: 7

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

Publications

LitVar

Other links and lift over

dbSNP: rs397509364; hg19: chr2-150427592;