rs1555187033

Variant names:

• chr11-112088965-GC-TT
• rs1555187033
• NM_003002.4:c.268_269delGCinsTT

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_003002.4(SDHD):​c.268_269delGCinsTT​(p.Ala90Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHD NM_003002.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.60

Genes affected

SDHD (HGNC:10683): (succinate dehydrogenase complex subunit D) This gene encodes a member of complex II of the respiratory chain, which is responsible for the oxidation of succinate. The encoded protein is one of two integral membrane proteins anchoring the complex to the matrix side of the mitochondrial inner membrane. Mutations in this gene are associated with the formation of tumors, including hereditary paraganglioma. Transmission of disease occurs almost exclusively through the paternal allele, suggesting that this locus may be maternally imprinted. There are pseudogenes for this gene on chromosomes 1, 2, 3, 7, and 18. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2013]

ENSG00000255292 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a chain Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial (size 102) in uniprot entity DHSD_HUMAN there are 30 pathogenic changes around while only 2 benign (94%) in NM_003002.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHD	NM_003002.4	c.268_269delGCinsTT	p.Ala90Leu	missense_variant		ENST00000375549.8	NP_002993.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHD	ENST00000375549.8	c.268_269delGCinsTT	p.Ala90Leu	missense_variant		1	NM_003002.4	ENSP00000364699.3
ENSG00000255292	ENST00000532699.1	n.268_269delGCinsTT		non_coding_transcript_exon_variant	Exon 3 of 6	3		ENSP00000456434.1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pheochromocytoma;C1847319:Carney-Stratakis syndrome;C1868633:Paragangliomas with sensorineural hearing loss;CN166604:Cowden syndrome 3 Uncertain:1

Apr 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 90 of the SDHD protein (p.Ala90Leu). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This variant has not been reported in the literature in individuals affected with SDHD-related conditions. ClinVar contains an entry for this variant (Variation ID: 465230). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Mitochondrial complex 2 deficiency, nuclear type 3 Uncertain:1

Jan 23, 2024

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Jul 05, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.268_269delGCinsTT variant (also known as p.A90L), located in coding exon 3 of the SDHD gene, results from an in-frame deletion of GC and insertion of TT at nucleotide positions 268 to 269. This results in the substitution of the alanine residue for a leucine residue at codon 90, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be neutral by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555187033; hg19: chr11-111959689;