15-40407639-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_002225.5(IVD):​c.148C>T​(p.Arg50Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000409 in 1,613,542 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R50G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000043 ( 0 hom. )

Consequence

IVD
NM_002225.5 missense

Scores

13
3
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 3.65

Publications

4 publications found
Variant links:
Genes affected
IVD (HGNC:6186): (isovaleryl-CoA dehydrogenase) Isovaleryl-CoA dehydrogenase (IVD) is a mitochondrial matrix enzyme that catalyzes the third step in leucine catabolism. The genetic deficiency of IVD results in an accumulation of isovaleric acid, which is toxic to the central nervous system and leads to isovaleric acidemia. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2017]
IVD Gene-Disease associations (from GenCC):
  • isovaleric acidemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Myriad Women’s Health, G2P, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_002225.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-40407639-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 648047.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.951
PP5
Variant 15-40407639-C-T is Pathogenic according to our data. Variant chr15-40407639-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 3567.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IVDNM_002225.5 linkc.148C>T p.Arg50Cys missense_variant Exon 2 of 12 ENST00000487418.8 NP_002216.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IVDENST00000487418.8 linkc.148C>T p.Arg50Cys missense_variant Exon 2 of 12 1 NM_002225.5 ENSP00000418397.3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152172
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251486
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000431
AC:
63
AN:
1461370
Hom.:
0
Cov.:
31
AF XY:
0.0000454
AC XY:
33
AN XY:
727042
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000549
AC:
61
AN:
1111548
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60384
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.435
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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
AF:
0.0000197
AC:
3
AN:
152172
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000800
Hom.:
0
Bravo
AF:
0.0000302
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Isovaleryl-CoA dehydrogenase deficiency Pathogenic:6
Jun 14, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 53 of the IVD protein (p.Arg53Cys). RNA analysis indicates that this missense change induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs34695403, gnomAD 0.003%). This missense change has been observed in individuals with isovaleric acidemia (PMID: 10677295, 31442447; Invitae). This variant is also known as 148C>T (Arg21Cys). ClinVar contains an entry for this variant (Variation ID: 3567). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Studies have shown that this missense change results in skipping of exon 2, but is expected to preserve the integrity of the reading-frame (PMID: 2063866, 10677295). For these reasons, this variant has been classified as Pathogenic. -

Oct 04, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: IVD c.148C>T (p.Arg50Cys) results in a non-conservative amino acid change in the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. However, at least one publication reports experimental evidence that this variant affects mRNA splicing and causes skipping of exon 2 (Vockley_2000). The variant allele was found at a frequency of 1.2e-05 in 251486 control chromosomes (gnomAD). c.148C>T has been reported in the literature in individuals affected with Isovaleryl-CoA Dehydrogenase Deficiency (Vockley_2000, Li_2019). These data indicate that the variant may be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 26990548, 22960500, 17001642, 31442447, 34394177, 10677295). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Feb 24, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 01, 2000
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Mar 07, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 16, 2020
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.47
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.51
CADD
Pathogenic
34
DANN
Pathogenic
1.0
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
0.98
.;D;D
M_CAP
Pathogenic
0.47
D
MetaRNN
Pathogenic
0.95
D;D;D
MetaSVM
Pathogenic
0.96
D
PhyloP100
3.7
PrimateAI
Uncertain
0.56
T
PROVEAN
Pathogenic
-7.3
.;D;D
REVEL
Pathogenic
0.84
Sift
Pathogenic
0.0
.;D;D
Sift4G
Pathogenic
0.0
D;D;D
Vest4
0.93
MVP
0.95
MPC
1.1
ClinPred
1.0
D
GERP RS
5.3
PromoterAI
-0.070
Neutral
Varity_R
0.94
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.11
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs34695403; hg19: chr15-40699840; API