4-145655145-A-T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_StrongPM2PP5

The NM_172250.3(MMAA):​c.970-2A>T variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,710 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 Pathogenic (no stars).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MMAA
NM_172250.3 splice_acceptor, intron

Scores

7
1
6
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic no assertion criteria provided P:1

Conservation

PhyloP100: 8.91

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 3.887828 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.6, offset of 23, new splice context is: attcgtatttctgcccgaAGtgg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 4-145655145-A-T is Pathogenic according to our data. Variant chr4-145655145-A-T is described in ClinVar as Pathogenic. ClinVar VariationId is 555331.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MMAANM_172250.3 linkc.970-2A>T splice_acceptor_variant, intron_variant Intron 6 of 6 ENST00000649156.2 NP_758454.1
MMAANM_001375644.1 linkc.970-2A>T splice_acceptor_variant, intron_variant Intron 6 of 6 NP_001362573.1
MMAAXM_011531684.4 linkc.970-2A>T splice_acceptor_variant, intron_variant Intron 6 of 6 XP_011529986.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MMAAENST00000649156.2 linkc.970-2A>T splice_acceptor_variant, intron_variant Intron 6 of 6 NM_172250.3 ENSP00000497008.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461710
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727156
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86188
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111914
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000936
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

Methylmalonic aciduria, cblA type Pathogenic:1
Dec 08, 2017
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.20
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;.;.;.;.;.
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.0
.;.;.;.;.;.
MetaRNN
Benign
0.0
.;.;.;.;.;.
MutationAssessor
Benign
0.0
.;.;.;.;.;.
PhyloP100
8.9
PROVEAN
Benign
0.0
.;.;.;.;.;.
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;.;.;.;.
Sift4G
Pathogenic
0.0
.;.;.;.;.;.
Vest4
0.0
GERP RS
5.7
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.99
Position offset: 2

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

Publications

Other links and lift over

dbSNP: rs1553959113; hg19: chr4-146576297; API