rs878854625

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_004168.4(SDHA):​c.1196C>A​(p.Pro399Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,128 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P399L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Consequence

SDHA
NM_004168.4 missense

Scores

14
4
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.25

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.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SDHANM_004168.4 linkc.1196C>A p.Pro399Gln missense_variant Exon 9 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.1196C>A p.Pro399Gln missense_variant Exon 9 of 15 1 NM_004168.4 ENSP00000264932.6 P31040-1
ENSG00000286001ENST00000651543.1 linkn.1065-1153C>A intron_variant Intron 8 of 23 ENSP00000499215.1 A0A494C1T6

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152128
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
31
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152128
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74312
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41410
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
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

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:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2
Mar 18, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P399Q variant (also known as c.1196C>A), located in coding exon 9 of the SDHA gene, results from a C to A substitution at nucleotide position 1196. The proline at codon 399 is replaced by glutamine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Jul 13, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

not provided Uncertain:1
May 09, 2018
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The P399Q variant in the SDHA gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The P399Q variant is not observed in large population cohorts (Lek et al., 2016). The P399Q variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In-silico analyses, including protein predictors and evolutionary conservation, support a deleterious effect. We interpret P399Q as a variant of uncertain significance. -

Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
Sep 27, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with glutamine, which is neutral and polar, at codon 399 of the SDHA protein (p.Pro399Gln). This variant is not present in population databases (gnomAD no frequency). 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: 480869). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SDHA protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.30
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.59
D;D;.;.
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.86
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
0.99
D;D;D;D
M_CAP
Pathogenic
0.36
D
MetaRNN
Pathogenic
0.94
D;D;D;D
MetaSVM
Uncertain
0.70
D
MutationAssessor
Pathogenic
4.0
.;H;.;.
PhyloP100
7.2
PrimateAI
Pathogenic
0.79
T
PROVEAN
Pathogenic
-7.5
.;D;D;D
REVEL
Pathogenic
0.82
Sift
Pathogenic
0.0
.;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
.;D;D;.
Vest4
0.89
MutPred
0.76
.;Gain of catalytic residue at P399 (P = 0.0344);Gain of catalytic residue at P399 (P = 0.0344);.;
MVP
0.88
MPC
1.3
ClinPred
1.0
D
GERP RS
5.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.96
gMVP
0.87
Mutation Taster
=18/82
disease causing

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: rs878854625; hg19: chr5-235390; COSMIC: COSV53766928; API