Genetic Variant MMAA:c.733+1G>T (chr4-145646157-G-T) – ACMG Classification: Pathogenic (14 pts)

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_172250.3(MMAA):c.733+1G>T variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,688 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MMAA
NM_172250.3 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 9.27

Publications

0 publications found

Variant links:

Genes affected

MMAA (HGNC:18871): (metabolism of cobalamin associated A) The protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase. Defects in this gene are a cause of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

MMAA Gene-Disease associations (from GenCC):

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

MMAA links:

ENSG00000248356 (HGNC:):

ENSG00000248356 links:

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ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.13603818 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 4-145646157-G-T is Pathogenic according to our data. Variant chr4-145646157-G-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2676599.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_172250.3. 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
	MMAA	NM_172250.3	MANE Select	c.733+1G>T		splice_donor intron	N/A	NP_758454.1	Q8IVH4
	MMAA	NM_001375644.1		c.733+1G>T		splice_donor intron	N/A	NP_001362573.1	Q8IVH4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
MMAA	ENST00000649156.2	MANE Select	c.733+1G>T	splice_donor intron	N/A	ENSP00000497008.1	Q8IVH4
MMAA	ENST00000511969.4	TSL:1	n.733+1G>T	splice_donor intron	N/A	ENSP00000427422.1	D6RIS5
MMAA	ENST00000541599.5	TSL:5	c.733+1G>T	splice_donor intron	N/A	ENSP00000442284.3	Q8IVH4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251400

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461688

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727148

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.0000447

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39676

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111862

Other (OTH)

AF:

0.00

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

ClinVar submissions

Significance:Pathogenic/Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Methylmalonic aciduria, cblA type (2)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.29

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.98

PhyloP100

9.3

GERP RS

5.3

Mutation Taster

=0/100

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.99

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.99

Position offset: -1

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over