5-218353-G-T

Variant names:

• chr5-218353-G-T
• rs1553996340
• NM_004168.4:c.-3G>T

Variant summary

Our verdict is Likely benign. The variant received -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, multiple submitters, no conflicts U:2
• 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]

ENSG00000286001 (HGNC:):

CCDC127 (HGNC:30520): (coiled-coil domain containing 127) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.-3G>T		5_prime_UTR_variant	Exon 1 of 15	ENST00000264932.11	NP_004159.2
CCDC127	NM_145265.3	c.-271C>A		upstream_gene_variant		ENST00000296824.4	NP_660308.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932	c.-3G>T		5_prime_UTR_variant	Exon 1 of 15	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.-3G>T		non_coding_transcript_exon_variant	Exon 1 of 24			ENSP00000499215.1
ENSG00000286001	ENST00000651543.1	n.-3G>T		5_prime_UTR_variant	Exon 1 of 24			ENSP00000499215.1
CCDC127	ENST00000296824.4	c.-271C>A		upstream_gene_variant		1	NM_145265.3	ENSP00000296824.2

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 AC: 0 AN: 26842

Gnomad4 AMR exome AF: 0.00 AC: 0 AN: 24642

Gnomad4 ASJ exome AF: 0.0000491 AC: 1 AN: 20378

Gnomad4 EAS exome AF: 0.00 AC: 0 AN: 30986

Gnomad4 SAS exome AF: 0.00 AC: 0 AN: 66078

Gnomad4 FIN exome AF: 0.00 AC: 0 AN: 33898

Gnomad4 NFE exome AF: 0.00000478 AC: 5 AN: 1046714

Gnomad4 Remaining exome AF: 0.00 AC: 0 AN: 53468

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Jul 11, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Nucleotide substitution has no predicted effect on splicing and is not conserved across species; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary cancer-predisposing syndrome Uncertain:1

May 20, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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
Mutation Taster		=299/1	polymorphism

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;