NM_000387.6:c.496C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000387.6(SLC25A20):​c.496C>T​(p.Arg166*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,786 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

SLC25A20
NM_000387.6 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 3.29

Publications

4 publications found
Variant links:
Genes affected
SLC25A20 (HGNC:1421): (solute carrier family 25 member 20) This gene product is one of several closely related mitochondrial-membrane carrier proteins that shuttle substrates between cytosol and the intramitochondrial matrix space. This protein mediates the transport of acylcarnitines into mitochondrial matrix for their oxidation by the mitochondrial fatty acid-oxidation pathway. Mutations in this gene are associated with carnitine-acylcarnitine translocase deficiency, which can cause a variety of pathological conditions such as hypoglycemia, cardiac arrest, hepatomegaly, hepatic dysfunction and muscle weakness, and is usually lethal in new born and infants. [provided by RefSeq, Jul 2008]
PRKAR2A-AS1 (HGNC:40471): (PRKAR2A antisense RNA 1)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-48862581-G-A is Pathogenic according to our data. Variant chr3-48862581-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 12135.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
SLC25A20NM_000387.6 linkc.496C>T p.Arg166* stop_gained Exon 5 of 9 ENST00000319017.5 NP_000378.1 O43772

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC25A20ENST00000319017.5 linkc.496C>T p.Arg166* stop_gained Exon 5 of 9 1 NM_000387.6 ENSP00000326305.4 O43772

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152104
Hom.:
0
Cov.:
32
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251456
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461682
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
727162
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1111846
Other (OTH)
AF:
0.00
AC:
0
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
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

Exome 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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152104
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41404
American (AMR)
AF:
0.00
AC:
0
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000165
AC:
2

ClinVar

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

Submissions by phenotype

Carnitine acylcarnitine translocase deficiency Pathogenic:5
Feb 25, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 01, 1999
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Nov 05, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: SLC25A20 c.496C>T (p.Arg166X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.2e-05 in 251456 control chromosomes (gnomAD). c.496C>T has been reported in the literature in at least two individuals (homozygous and a compound heterozygous) affected with Carnitine-Acylcarnitine Translocase Deficiency (Costa_1999 and Wang_2011). One homozygous individual with this variant was reported as having a complete deficiency of Carnitine Acylcarnitine carrier enzyme activity at day 3 and confirmed three months later in fibroblasts, however, primary data supporting this finding were not reported (Costa_1999). To our knowledge, no other experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Mar 30, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 16, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 12135). This premature translational stop signal has been observed in individual(s) with carnitine-acylcarnitine translocase deficiency (PMID: 10384384, 12559850). This variant is present in population databases (rs151340616, gnomAD 0.006%). This sequence change creates a premature translational stop signal (p.Arg166*) in the SLC25A20 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SLC25A20 are known to be pathogenic (PMID: 25614308). -

not provided Pathogenic:1
Apr 09, 2018
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The R166X nonsense variant in the SLC25A20 gene has been reported previously in association with carnitine-acylcarnitine translocase deficiency (Costa et al., 1999; Wang et al., 2011). The R166X variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). This pathogenic variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.62
CADD
Pathogenic
38
DANN
Uncertain
1.0
Eigen
Pathogenic
0.85
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.87
D
PhyloP100
3.3
Vest4
0.76
GERP RS
4.9
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs151340616; hg19: chr3-48900014; API