NM_004168.4:c.242C>T

Variant names:

• chr5-224451-C-T
• rs1553997357
• NM_004168.4:c.242C>T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004168.4(SDHA):​c.242C>T​(p.Ser81Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SDHA NM_004168.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.50

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.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.852

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.242C>T	p.Ser81Phe	missense_variant	Exon 3 of 15	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.242C>T	p.Ser81Phe	missense_variant	Exon 3 of 15	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.242C>T		non_coding_transcript_exon_variant	Exon 3 of 24			ENSP00000499215.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Apr 11, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a SDHA-related disease. This sequence change replaces serine with phenylalanine at codon 81 of the SDHA protein (p.Ser81Phe). The serine residue is highly conserved and there is a large physicochemical difference between serine and phenylalanine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Dec 13, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S81F variant (also known as c.242C>T), located in coding exon 3 of the SDHA gene, results from a C to T substitution at nucleotide position 242. The serine at codon 81 is replaced by phenylalanine, an amino acid with highly dissimilar 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	T;T;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.85	D;D;D;D
MetaSVM	Uncertain	0.063	D
MutationAssessor	Uncertain	2.3	.;M;.;M
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-2.9	.;D;D;D
REVEL	Uncertain	0.53
Sift	Uncertain	0.0010	.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	.;D;D;.
Vest4		0.89
MutPred		0.59		Gain of sheet (P = 0.0085);Gain of sheet (P = 0.0085);Gain of sheet (P = 0.0085);Gain of sheet (P = 0.0085);
MVP		0.90
MPC		1.4
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.92
gMVP		0.96

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

Other links and lift over

dbSNP: rs1553997357; hg19: chr5-224566;