5-233650-G-C

Variant names:

• chr5-233650-G-C
• rs200021115
• NM_004168.4:c.1064+5G>C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3

The NM_004168.4(SDHA):​c.1064+5G>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,456 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: SDHA NM_004168.4 splice_region, intron
• Scores: Splicing: ADA: 0.9995
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2 B:1
• Conservation: PhyloP100: 1.33

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 1 ACMG points.

• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.1064+5G>C		splice_region_variant, intron_variant	Intron 8 of 14	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.1064+5G>C		splice_region_variant, intron_variant	Intron 8 of 14	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.1064+5G>C		splice_region_variant, intron_variant	Intron 8 of 23			ENSP00000499215.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251286 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135812

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461456 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727048

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: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Jan 11, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 8 of the SDHA gene. It does not directly change the encoded amino acid sequence of the SDHA protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs200021115, gnomAD 0.003%). 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: 412345). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant is associated with inconclusive levels of altered splicing (internal data). 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 15, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1064+5G>C intronic variant results from a G to C substitution 5 nucleotides after coding exon 8 in the SDHA gene. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis for this alteration is inconclusive. RNA studies have demonstrated that this alteration results in a splice defect; the clinical impact of this abnormal splicing is unknown at this time (Ambry internal data). Based on the available evidence, the clinical significance of this variant remains unclear. -

SDHA-related disorder Benign:1

Sep 18, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.76
CADD	Benign	19
DANN	Benign	0.62

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.13		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: rs200021115; hg19: chr5-233765;