rs1061517

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_004168.4(SDHA):ā€‹c.1A>Cā€‹(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,460,298 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 (ā˜…ā˜…).

Frequency

Genomes: š‘“ 0.0000066 ( 0 hom., cov: 34)
Exomes š‘“: 0.0000038 ( 0 hom. )

Consequence

SDHA
NM_004168.4 start_lost

Scores

3
3
10

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 0.636
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1
Start lost variant, no new inframe start found.
PP5
Variant 5-218356-A-C is Pathogenic according to our data. Variant chr5-218356-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 8744.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
SDHANM_004168.4 linkuse as main transcriptc.1A>C p.Met1? start_lost 1/15 ENST00000264932.11 NP_004159.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
SDHAENST00000264932.11 linkuse as main transcriptc.1A>C p.Met1? start_lost 1/151 NM_004168.4 ENSP00000264932 P1P31040-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152158
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000382
AC:
5
AN:
1308140
Hom.:
0
Cov.:
31
AF XY:
0.00000310
AC XY:
2
AN XY:
645810
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000477
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152158
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
74324
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mitochondrial complex II deficiency, nuclear type 1 Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 01, 2000- -
Paragangliomas 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 19, 2023This sequence change affects the initiator methionine of the SDHA mRNA. The next in-frame methionine is located at codon 114. This variant is not present in population databases (gnomAD no frequency). Disruption of the initiator codon has been observed in individuals with pheochromocytoma, gastrointestinal stromal tumor, and clinical features of complex II deficiency (PMID: 10746566, 28384794, 31413764). ClinVar contains an entry for this variant (Variation ID: 8744). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that disruption of the initiator codon affects SDHA function (PMID: 10746566). For these reasons, this variant has been classified as Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsJul 06, 2020The p.M1? pathogenic mutation (also known as c.1A>C) is located in coding exon 1 of the SDHA gene and results from an A to C substitution at nucleotide position 1. This alters the methionine residue at the initiation codon. There is an in-frame methionine 114 amino acids downstream from this initiation site which may result in an N-terminal truncation; however, direct evidence is unavailable. This alteration has been reported in an individual with Leigh syndrome who also carried a functionally deleterious SDHA alteration in trans (Parfait B et al. Hum. Genet. 2000 Feb;106:236-43). This alteration has also been observed individuals with paraganglioma and gastrointestinal stromal tumor (GIST) (Bausch B et al. JAMA Oncol. 2017 Sep;3(9):1204-1212; Carrera S et al. Hered. Cancer Clin. Pract. 2019 Aug;17:23). In addition to the clinical data presented in the literature, since sequence variations that modify the initiation codon (ATG) are expected to result in either loss of translation initiation, N-terminal truncation, or cause a shift in the mRNA reading frame, this alteration is interpreted as a disease-causing mutation. -
Neurodegeneration with ataxia and late-onset optic atrophy Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMay 03, 2023Variant summary: SDHA c.1A>C (p.Met1?) alters the initiation codon and is predicted to result either in absence of the protein or truncation of the encoded protein due to translation initiation at a downstream codon. The next in-frame Methionine is located at codon 114 in exon 4 of the encoded protein sequence. The variant was absent in 114846 control chromosomes. c.1A>C has been reported in the literature as a compound heterozygous genotype in an individual affected with features of Leigh Syndrome with Succinate dehydrogenase deficiency (example, Parfait_2000) and as a heterozygous genotype in individuals affected with features of extra-adrenal thoracid paraganglioma and/or Gastrointestinal stromal tumors (GISTs) (example, Bausch_2017, Carrera_2019). At least one publication reports experimental evidence evaluating an impact on transcript levels (Parfait_2000). The most pronounced variant effect results in mutant transcript representing only 10% of total Flavoprotein (Fp) transcripts, suggesting a high instability of this transcript. The following publications have been ascertained in the context of this evaluation (PMID: 28384794, 31413764, 10746566). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Paragangliomas 5 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingMyriad Genetics, Inc.Aug 10, 2023This variant is considered pathogenic. This variant is located within the gene translation start codon (p.Met1?) and is predicted to result in abnormal protein translation. This variant has been reported in multiple individuals with clinical features of gene-specific disease [PMID: 28384794, 35014173, 10746566, 32971818]. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Uncertain
0.13
CADD
Benign
14
DANN
Benign
0.48
DEOGEN2
Benign
0.26
T;T;.;.
Eigen
Benign
-0.79
Eigen_PC
Benign
-0.75
FATHMM_MKL
Benign
0.61
D
LIST_S2
Uncertain
0.90
D;D;D;D
M_CAP
Pathogenic
0.90
D
MetaRNN
Pathogenic
0.99
D;D;D;D
MetaSVM
Benign
-0.92
T
MutationTaster
Benign
1.0
D;D;D
PROVEAN
Benign
-0.26
.;N;N;N
REVEL
Uncertain
0.36
Sift
Benign
0.093
.;T;T;T
Sift4G
Benign
0.15
T;T;T;T
Polyphen
0.0
.;B;B;.
Vest4
0.83
MutPred
0.99
Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);
MVP
0.69
ClinPred
0.74
D
GERP RS
2.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.32
gMVP
0.63

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1061517; hg19: chr5-218471; API