Genetic Variant MMAA:p.Leu217Ser (chr4-145646073-T-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B.

PM1PM2PP3_Moderate

The NM_172250.3(MMAA):c.650T>C(p.Leu217Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,808 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L217L) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

MMAA
NM_172250.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.48

Publications

4 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:

ENSG00000248356 (HGNC:):

ENSG00000248356 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_172250.3

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.929

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMAA	NM_172250.3 link	c.650T>C	p.Leu217Ser	missense_variant	Exon 4 of 7	ENST00000649156.2	NP_758454.1	Q8IVH4
MMAA	NM_001375644.1 link	c.650T>C	p.Leu217Ser	missense_variant	Exon 4 of 7		NP_001362573.1
MMAA	XM_011531684.4 link	c.650T>C	p.Leu217Ser	missense_variant	Exon 4 of 7		XP_011529986.1	Q8IVH4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMAA	ENST00000649156.2 link	c.650T>C	p.Leu217Ser	missense_variant	Exon 4 of 7		NM_172250.3	ENSP00000497008.1		Q8IVH4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251418

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461808

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727204

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:

0.0000252

AC:

AN:

39682

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111954

Other (OTH)

AF:

0.0000166

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.515

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:

0.0000312

Hom.:

Bravo

AF:

0.00000378

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.82

BayesDel_addAF

Pathogenic

0.35

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.78

D;.;D;D;D;D

Eigen

Pathogenic

0.89

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.96

.;D;.;.;D;D

M_CAP

Pathogenic

0.43

MetaRNN

Pathogenic

0.93

D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.7

H;.;H;H;H;.

PhyloP100

7.5

PrimateAI

Pathogenic

0.82

PROVEAN

Pathogenic

-5.0

.;.;D;.;.;.

REVEL

Pathogenic

0.94

Sift

Uncertain

0.021

.;.;D;.;.;.

Sift4G

Pathogenic

0.0

.;.;D;.;.;D

Polyphen

1.0

D;.;D;D;D;.

Vest4

0.96, 0.96

MVP

0.98

MPC

0.63

ClinPred

1.0

GERP RS

5.4

Varity_R

0.75

gMVP

0.93

Mutation Taster

=42/58

disease causing

(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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over