rs766667009

Variant names:

• chr5-251104-G-A
• rs766667009
• NM_004168.4:c.1663+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr5-251104-G-A
• chr5-251104-G-C
• chr5-251104-G-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004168.4(SDHA):​c.1663+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,230 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: SDHA NM_004168.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.02
• Publications: 1 publications found

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]

SDHA Gene-Disease associations (from GenCC):

• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• pheochromocytoma/paraganglioma syndrome 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mitochondrial complex II deficiency, nuclear type 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• neurodegeneration with ataxia and late-onset optic atrophy

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• gastrointestinal stromal tumor

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Leigh syndrome with leukodystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mitochondrial complex II deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy 1GG

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000286001 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-251104-G-A is Pathogenic according to our data. Variant chr5-251104-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 956996.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.1663+1G>A		splice_donor_variant, intron_variant	Intron 12 of 14	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.1663+1G>A		splice_donor_variant, intron_variant	Intron 12 of 14	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.*396+1G>A		splice_donor_variant, intron_variant	Intron 11 of 23			ENSP00000499215.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1459230 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 725978

African (AFR) AF: 0.00 AC: 0 AN: 33386

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86158

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4132

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111400

Other (OTH) AF: 0.00 AC: 0 AN: 60192

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pheochromocytoma/paraganglioma syndrome 5 Pathogenic:1

Jun 13, 2023

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -

Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Pathogenic:1

Sep 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 12 of the SDHA gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or altered protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with clinical features of paraganglioma-pheochromocytoma syndrome and/or colon adenocarcinoma (PMID: 29625052; internal data). ClinVar contains an entry for this variant (Variation ID: 956996). Studies have shown that disruption of this splice site results in skipping of exon 12 and skipping of exon 12-13, and produces a non-functional protein and/or introduces a premature termination codon (internal data). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Mar 23, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1663+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 12 of the SDHA gene. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). Other variant(s) impacting the same donor site (c.1663+3G>C) have been identified in individual(s) with features consistent with SDHA-related paraganglioma-pheochromocytoma syndrome (Dwight T et al. Am J Surg Pathol, 2013 Feb;37:226-33; Ben Aim L et al. J Med Genet, 2019 08;56:513-520). c.1663+1G>A is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Dilated cardiomyopathy 1GG;C3279992:Pheochromocytoma/paraganglioma syndrome 5;C5543254:Neurodegeneration with ataxia and late-onset optic atrophy;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Pathogenic:1

Nov 07, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	32
DANN	Uncertain	0.98
Eigen	Pathogenic	0.84
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.0
GERP RS		3.6
PromoterAI		-0.016	Neutral
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.75
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs766667009; hg19: chr5-251219;