5-218353-G-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_004168.4(SDHA):c.-3G>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000459 in 1,306,702 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000046 (0 hom.)
• Consequence: SDHA NM_004168.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0690

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]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHA	NM_004168.4	c.-3G>T		5_prime_UTR_variant	1/15	ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11	c.-3G>T		5_prime_UTR_variant	1/15	1	NM_004168.4	P1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000459 AC: 6 AN: 1306702 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 644858

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000491

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000478

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 20, 2023

The c.-3G>T variant is located in the 5' untranslated region (5’ UTR) of the SDHA gene. This variant results from a G to T substitution 3 bases upstream from the first translated codon. This nucleotide position is well conserved on limited sequence alignment. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
Cadd	Benign	7.9
Dann	Benign	0.70
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs1553996340; hg19: chr5-218468;