rs768276870

Positions:

• chr5-233649-C-A
• chr5-233649-C-G
• chr5-233649-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_004168.4(SDHA):​c.1064+4C>A variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,380 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: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SDHA NM_004168.4 splice_donor_region, intron
• Scores: Splicing: ADA: 0.00003529
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.213

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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHA	NM_004168.4	c.1064+4C>A		splice_donor_region_variant, intron_variant		ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11	c.1064+4C>A		splice_donor_region_variant, intron_variant		1	NM_004168.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461380 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727016

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 31, 2021

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 of the intron. This variant is not present in population databases (ExAC no frequency). 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: 472297). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	4.9
DANN	Benign	0.75

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000035
dbscSNV1_RF	Benign	0.0040
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: rs768276870; hg19: chr5-233764;