5-254396-C-T

Variant names:

• chr5-254396-C-T
• rs878854630
• NM_004168.4:c.1798C>T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_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).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 30)
  • Exomes 𝑓: 0.000033 (0 hom.)
• Consequence: SDHA NM_004168.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 2.13

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]

ENSG00000286001 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.1798C>T	p.Arg600Trp	missense_variant	Exon 14 of 15	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.1798C>T	p.Arg600Trp	missense_variant	Exon 14 of 15	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.*531C>T		non_coding_transcript_exon_variant	Exon 13 of 24			ENSP00000499215.1
ENSG00000286001	ENST00000651543.1	n.*531C>T		3_prime_UTR_variant	Exon 13 of 24			ENSP00000499215.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152102 Hom.: 0 Cov.: 30

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

GnomAD4 exome AF: 0.0000331 AC: 48 AN: 1449586 Hom.: 0 Cov.: 32 AF XY: 0.0000320 AC XY: 23 AN XY: 719794

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: 0.0000416

Gnomad4 OTH exome AF: 0.0000334

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152102 Hom.: 0 Cov.: 30 AF XY: 0.0000135 AC XY: 1 AN XY: 74314

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0000942

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

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. -

Dilated cardiomyopathy 1GG;C3279992:Paragangliomas 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

- -

Paragangliomas 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). -

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 -

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;.;.
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

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

LitVar

Other links and lift over

dbSNP: rs878854630; hg19: chr5-254511;