Genetic Variant MMAA:p.Pro8Leu (chr4-145639162-C-T) – ACMG Classification: Uncertain_significance (0 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_172250.3(MMAA):c.23C>T(p.Pro8Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MMAA
NM_172250.3 missense

Scores

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: 3.46

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: Myriad Women’s Health, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, G2P

MMAA links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.18316478).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMAA	NM_172250.3 link	c.23C>T	p.Pro8Leu	missense_variant	Exon 2 of 7	ENST00000649156.2	NP_758454.1	Q8IVH4
MMAA	NM_001375644.1 link	c.23C>T	p.Pro8Leu	missense_variant	Exon 2 of 7		NP_001362573.1
MMAA	XM_011531684.4 link	c.23C>T	p.Pro8Leu	missense_variant	Exon 2 of 7		XP_011529986.1	Q8IVH4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMAA	ENST00000649156.2 link	c.23C>T	p.Pro8Leu	missense_variant	Exon 2 of 7		NM_172250.3	ENSP00000497008.1		Q8IVH4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461838

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727220

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111982

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblA type

Uncertain:1

Mar 18, 2025

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.082

BayesDel_addAF

Uncertain

0.065

BayesDel_noAF

Benign

-0.14

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.19

T;.;T;T;T;T

Eigen

Benign

-0.23

Eigen_PC

Benign

-0.16

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.83

.;T;.;.;T;T

M_CAP

Uncertain

0.088

MetaRNN

Benign

0.18

T;T;T;T;T;T

MetaSVM

Uncertain

0.20

MutationAssessor

Benign

2.0

M;.;M;M;M;.

PhyloP100

3.5

PrimateAI

Benign

0.27

PROVEAN

Benign

-0.83

.;.;N;.;.;.

REVEL

Benign

0.24

Sift

Uncertain

0.0050

.;.;D;.;.;.

Sift4G

Pathogenic

0.0

.;.;D;.;.;D

Polyphen

0.0010

B;.;B;B;B;.

Vest4

0.27, 0.35

MutPred

0.34

Loss of glycosylation at P8 (P = 0.0167);Loss of glycosylation at P8 (P = 0.0167);Loss of glycosylation at P8 (P = 0.0167);Loss of glycosylation at P8 (P = 0.0167);Loss of glycosylation at P8 (P = 0.0167);Loss of glycosylation at P8 (P = 0.0167);

MVP

0.92

MPC

0.26

ClinPred

0.55

GERP RS

4.6

Varity_R

0.074

gMVP

0.53

Mutation Taster

=80/20

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over