5-254396-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PP3_Strong

The NM_004168.4(SDHA):​c.1798C>T​(p.Arg600Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000312 in 1,601,688 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R600Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)
Exomes 𝑓: 0.000033 ( 0 hom. )

Consequence

SDHA
NM_004168.4 missense

Scores

11
7
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:5

Conservation

PhyloP100: 2.13

Publications

2 publications found
Variant links:
Genes affected
SDHA (HGNC:10680): (succinate dehydrogenase complex flavoprotein subunit A) This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2014]
SDHA Gene-Disease associations (from GenCC):
  • hereditary pheochromocytoma-paraganglioma
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • pheochromocytoma/paraganglioma syndrome 5
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • mitochondrial complex II deficiency, nuclear type 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • neurodegeneration with ataxia and late-onset optic atrophy
    Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • Leigh syndrome
    Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • gastrointestinal stromal tumor
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Leigh syndrome with leukodystrophy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • mitochondrial complex II deficiency
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • dilated cardiomyopathy 1GG
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

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 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_004168.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SDHANM_004168.4 linkc.1798C>T p.Arg600Trp missense_variant Exon 14 of 15 ENST00000264932.11 NP_004159.2 P31040-1A0A024QZ30

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SDHAENST00000264932.11 linkc.1798C>T p.Arg600Trp missense_variant Exon 14 of 15 1 NM_004168.4 ENSP00000264932.6 P31040-1
ENSG00000286001ENST00000651543.1 linkn.*531C>T non_coding_transcript_exon_variant Exon 13 of 24 ENSP00000499215.1 A0A494C1T6
ENSG00000286001ENST00000651543.1 linkn.*531C>T 3_prime_UTR_variant Exon 13 of 24 ENSP00000499215.1 A0A494C1T6

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152102
Hom.:
0
Cov.:
30
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:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000421
AC:
1
AN:
237692
AF XY:
0.00000781
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:
0.00000935
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000331
AC:
48
AN:
1449586
Hom.:
0
Cov.:
32
AF XY:
0.0000320
AC XY:
23
AN XY:
719794
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33172
American (AMR)
AF:
0.00
AC:
0
AN:
43140
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25806
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39454
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5382
European-Non Finnish (NFE)
AF:
0.0000416
AC:
46
AN:
1105864
Other (OTH)
AF:
0.0000334
AC:
2
AN:
59910
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.433
Heterozygous variant carriers
0
4
8
13
17
21
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:
0.0000131
AC:
2
AN:
152102
Hom.:
0
Cov.:
30
AF XY:
0.0000135
AC XY:
1
AN XY:
74314
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41360
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
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

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1
Aug 02, 2024
Ambry Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R600W variant (also known as c.1798C>T), located in coding exon 14 of the SDHA gene, results from a C to T substitution at nucleotide position 1798. The arginine at codon 600 is replaced by tryptophan, an amino acid with dissimilar properties. This variant has been observed in at least one individual with a personal and/or family history that is consistent with SDHA-related paraganglioma-pheochromocytoma syndrome (Ambry internal data). Based on internal structural analysis, the variant is moderately destabilizing to the local structure (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

not specified Uncertain:1
May 05, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: SDHA c.1798C>T (p.Arg600Trp) results in a non-conservative amino acid change located in the C-terminal domain (IPR015939) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 3.1e-05 in 1595078 control chromosomes (gnomAD v4.1). This frequency is not significantly higher than estimated for a pathogenic variant in SDHA causing Neurodegeneration With Ataxia And Late-Onset Optic Atrophy, allowing no conclusion about variant significance. To our knowledge, no occurrence of c.1798C>T in individuals affected with Neurodegeneration With Ataxia And Late-Onset Optic Atrophy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 239659). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Pheochromocytoma/paraganglioma syndrome 5 Uncertain:1
May 21, 2025
Molecular Pathology, Peter Maccallum Cancer Centre
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jul 15, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
Jan 27, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with SDHA-related conditions. ClinVar contains an entry for this variant (Variation ID: 239659). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 600 of the SDHA protein (p.Arg600Trp). -

Dilated cardiomyopathy 1GG;C3279992:Pheochromocytoma/paraganglioma syndrome 5;C5543254:Neurodegeneration with ataxia and late-onset optic atrophy;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
Sep 24, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.57
D;D;.;.
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Uncertain
0.93
D;D;T;D
M_CAP
Pathogenic
0.75
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Uncertain
0.74
D
MutationAssessor
Pathogenic
4.7
.;H;.;.
PhyloP100
2.1
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-5.9
.;D;N;D
REVEL
Pathogenic
0.83
Sift
Pathogenic
0.0
.;D;D;D
Sift4G
Uncertain
0.0050
D;D;D;D
Polyphen
1.0
.;D;D;.
Vest4
0.79
MutPred
0.88
.;Loss of disorder (P = 0.0089);.;.;
MVP
0.95
MPC
1.2
ClinPred
1.0
D
GERP RS
3.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
Varity_R
0.85
gMVP
0.91
Mutation Taster
=26/74
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs878854630; hg19: chr5-254511; COSMIC: COSV106371228; COSMIC: COSV106371228; API