rs1061517

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PS1_ModeratePP5_Very_Strong

The NM_004168.4(SDHA):c.1A>C(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 (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000038 ( 0 hom. )

Consequence

SDHA
NM_004168.4 start_lost

Scores

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]

SDHA links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Start lost variant, no new inframe start found.

PS1

Another start lost variant in NM_004168.4 (SDHA) was described as [Pathogenic] in ClinVar as 1408872

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	UniProt
SDHA	NM_004168.4 linkuse as main transcript	c.1A>C	p.Met1?	start_lost	1/15	ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11 linkuse as main transcript	c.1A>C	p.Met1?	start_lost	1/15	1	NM_004168.4	P1	P31040-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152158

Hom.:

Cov.:

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:

AN:

1308140

Hom.:

Cov.:

AF XY:

0.00000310

AC XY:

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:

AN:

152158

Hom.:

Cov.:

AF XY:

0.00

AC XY:

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 provided

literature only

OMIM

Feb 01, 2000

- -

Paragangliomas 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 19, 2023

This 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 submitter

clinical testing

Ambry Genetics

Jul 06, 2020

The 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 submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 03, 2023

Variant 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 submitter

clinical testing

Myriad Genetics, Inc.

Aug 10, 2023

This 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

BayesDel_noAF

Uncertain

0.13

CADD

Benign

DANN

Benign

0.48

DEOGEN2

Benign

0.26

T;T;.;.

Eigen

Benign

-0.79

Eigen_PC

Benign

-0.75

FATHMM_MKL

Benign

0.61

LIST_S2

Uncertain

0.90

D;D;D;D

M_CAP

Pathogenic

0.90

MetaRNN

Pathogenic

0.99

D;D;D;D

MetaSVM

Benign

-0.92

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

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over