rs1555186981

Variant names:

• chr11-112088896-ACT-GCC
• NM_003002.4:c.199_201delACTinsGCC

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_003002.4(SDHD):​c.199_201delACTinsGCC​(p.Thr67Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T67I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHD NM_003002.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.88
• Publications: 0 publications found

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]

SDHD Gene-Disease associations (from GenCC):

• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• pheochromocytoma

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• pheochromocytoma/paraganglioma syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• Carney-Stratakis syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• mitochondrial complex II deficiency, nuclear type 1

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• renal cell carcinoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• mitochondrial complex 2 deficiency, nuclear type 3

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• mitochondrial complex II deficiency

  Inheritance: AR Classification: MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• Cowden disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• intestinal cancer

  Inheritance: AD Classification: LIMITED Submitted by: G2P
• mitochondrial disease

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ENSG00000255292 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 32 uncertain in NM_003002.4

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHD	NM_003002.4	c.199_201delACTinsGCC	p.Thr67Ala	missense_variant		ENST00000375549.8	NP_002993.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHD	ENST00000375549.8	c.199_201delACTinsGCC	p.Thr67Ala	missense_variant		1	NM_003002.4	ENSP00000364699.3
ENSG00000255292	ENST00000532699.1	n.199_201delACTinsGCC		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:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Jun 13, 2019

Invitae

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine with alanine at codon 67 of the SDHD protein (p.Thr67Ala). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and alanine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with an SDHD-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.9

Splicing

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

Other links and lift over

hg19: chr11-111959620;