rs878854627

chr5-236598-TGG-T

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1 PM2 PP3_Moderate PP5_Very_Strong

The NM_004168.4(SDHA):c.1432_1432+1del variant causes a splice donor, coding sequence change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,230 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000038 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SDHA NM_004168.4 splice_donor, coding_sequence
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 9.58

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 Pathogenic. Variant got 20 ACMG points.

• PVS1: Splicing 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-236598-TGG-T is Pathogenic according to our data. Variant chr5-236598-TGG-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 239647.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHA	NM_004168.4	c.1432_1432+1del		splice_donor_variant, coding_sequence_variant	10/15	ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11	c.1432_1432+1del		splice_donor_variant, coding_sequence_variant	10/15	1	NM_004168.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152230 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251166 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135740

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000376 AC: 55 AN: 1461504 Hom.: 0 AF XY: 0.0000454 AC XY: 33 AN XY: 727066

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: 0.0000486

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152230 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 11, 2022

- -

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 05, 2024

This variant results in the deletion of part of exon 10 (c.1432_1432+1del) of the SDHA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in SDHA are known to be pathogenic (PMID: 22974104, 24781757). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has been observed in individuals with breast cancer, paraganglioma-pheochromocytoma syndrome, and/or renal cancer (PMID: 29177515, 30877234, 32782288, 34750850; Invitae). ClinVar contains an entry for this variant (Variation ID: 239647). Studies have shown that this variant is associated with inconclusive levels of altered splicing (Invitae). For these reasons, this variant has been classified as Pathogenic. -

Dilated cardiomyopathy 1GG Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 30, 2023

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 28, 2022

Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 24781757, 22974104, 31263571, 16199547, 30877234, 29177515, 26556299, 34750850, 32782288, 35053433) -

Paraganglioma;C0031511:Pheochromocytoma Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Cancer Variant Interpretation Group UK, Institute of Cancer Research, London

Jul 10, 2020

This variant has been observed in a male proband with phaeochromocytoma and lung nodule. The variant has previously been reported in the literature, including in a male with glomus jugulare tumour (PMID: 29177515); a male with retroperitoneal paraganglioma (PMID 28384794); a male with gallbladder paraganglioma, pancreatic neuroendocrine tumour and metastatic prostate cancer (PMID: 32534711); and a female with thoracic paraganglioma (PMCID: PMC7209502) (PS4_moderate). The variant is absent from population database gnomAD (PM2_supporting) and is predicted to result in loss of protein function (PVS1_very_strong). Data included in classification: Prevalence in affected versus controls GT-AG 1,2 splice site variant predicted to result in loss of protein function Data not included in classification: Functional data -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 24, 2023

The c.1432_1432+1delGG pathogenic mutation spans the coding exon 10/intron 10 boundary of the SDHA gene and results from the deletion of 2 nucleotides at nucleotide positions c.1432 and c.1432+1. The deleted region includes the last nucleotide and canonical donor site, which is highly conserved in available vertebrate species. This alteration has been observed in multiple individuals with a personal and/or family history that is consistent with SDHA-related disease (Ambry internal data; Bausch B et al. JAMA Oncol 2017 Sep;3(9):1204-1212; van der Tuin K et al. J Clin Endocrinol Metab 2018 02;103(2):438-445). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). 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. As such, this alteration is classified as a disease-causing mutation. -

Neurodegeneration with ataxia and late-onset optic atrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 04, 2023

Variant summary: SDHA c.1432_1432+1delGG is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 251166 control chromosomes (gnomAD). c.1432_1432+1delGG has been reported in the literature in individuals affected with paraganglioma or cancers including renal cancer (van der Tuin_2018, Ben Aim_2019, Hartman_2020, Parisien-La Salle_2022). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 29177515, 30877234, 34750850, 32782288). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Paragangliomas 5 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Feb 08, 2024

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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs878854627; hg19: chr5-236713; COSMIC: COSV53775737; COSMIC: COSV53775737;