NM_003002.4:c.255G>C

Variant names:

• chr11-112088952-G-C
• rs199517389
• NM_003002.4:c.255G>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1 BP4

The NM_003002.4(SDHD):​c.255G>C​(p.Leu85Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,613,910 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 Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar.

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: SDHD NM_003002.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:2
• Conservation: PhyloP100: 1.77
• Publications: 2 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 1 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 39 uncertain in NM_003002.4
• BP4: Computational evidence support a benign effect (MetaRNN=0.2761344).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003002.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHD	NM_003002.4	MANE Select	c.255G>C	p.Leu85Phe	missense	Exon 3 of 4	NP_002993.1
	SDHD	NM_001276506.2		c.255G>C	p.Leu85Phe	missense	Exon 3 of 5	NP_001263435.1
	SDHD	NM_001276504.2		c.138G>C	p.Leu46Phe	missense	Exon 2 of 3	NP_001263433.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHD	ENST00000375549.8	TSL:1 MANE Select	c.255G>C	p.Leu85Phe	missense	Exon 3 of 4	ENSP00000364699.3
	ENSG00000255292	ENST00000532699.1	TSL:3	n.255G>C		non_coding_transcript_exon	Exon 3 of 6	ENSP00000456434.1
	SDHD	ENST00000528048.5	TSL:1	c.169+979G>C		intron	N/A	ENSP00000436217.1

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152152 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000410

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251442 AF XY: 0.00000736

Gnomad AFR exome AF: 0.000123

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461758 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 727188

African (AFR) AF: 0.000448 AC: 15 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5676

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111990

Other (OTH) AF: 0.0000497 AC: 3 AN: 60386

GnomAD4 genome AF: 0.000118 AC: 18 AN: 152152 Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6 AN XY: 74316

African (AFR) AF: 0.000410 AC: 17 AN: 41438

American (AMR) AF: 0.0000655 AC: 1 AN: 15266

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68018

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000564 Hom.: 0

Bravo AF: 0.000136

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Jul 09, 2025

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis suggests that this missense variant does not alter protein structure/function; Identified in a patient with paraganglioma in published literature (PMID: 34877445); This variant is associated with the following publications: (PMID: 24728327, 34877445)

Nov 01, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The SDHD c.255G>C (p.Leu85Phe) variant has been identified in the published literature in reportedly healthy individuals (PMID: 24728327 (2014)). The frequency of this variant in the general population, 0.00032 (8/24966 chromosomes in African/African American subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant.

Hereditary cancer-predisposing syndrome Benign:2

Oct 01, 2021

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Mar 31, 2021

Sema4, Sema4

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

not specified Uncertain:1

Mar 13, 2021

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: SDHD c.255G>C (p.Leu85Phe) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251442 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.255G>C in individuals affected with Hereditary Paraganglioma-Pheochromocytoma Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. At-least one co-occurrence with another pathogenic variant(s) have been observed at our laboratory (SDHB c.600G>T , p.Trp200Cys), providing supporting evidence for a benign role. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=2, likely benign, n=1). Based on the evidence outlined above, the variant was classified as uncertain significance.

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

Jan 16, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 85 of the SDHD protein (p.Leu85Phe). This variant is present in population databases (rs199517389, gnomAD 0.03%). 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: 412501). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SDHD protein function with a negative predictive value of 95%. 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

Dec 18, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Pheochromocytoma/paraganglioma syndrome 1 Uncertain:1

Jul 25, 2023

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The SDHD c.255G>C (p.Leu85Phe) missense change has a maximum subpopulation frequency of 0.032% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL is inconclusive about a pathogenic or benign effect of this variant on protein function, and to our knowledge functional studies have not been performed. To our knowledge, this variant has not been reported in individuals with hereditary paraganglioma-pheochromocytoma. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance.

Hereditary pheochromocytoma-paraganglioma Uncertain:1

May 14, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces leucine with phenylalanine at codon 85 of the SDHD protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SDHD-related disorders in the literature. A variant with a different nucleotide change but same protein change has been reported in an individual affected with lymphoma and a paraganglioma (SDHD: c.255G>T; p.Leu85Phe, PMID: 34877445). This variant has been identified in 9/282832 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Benign	-0.063	T
BayesDel_noAF	Uncertain	0.040
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	D
Eigen	Benign	-0.12
Eigen_PC	Benign	-0.0015
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Benign	0.82	T
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.28	T
MetaSVM	Uncertain	0.75	D
MutationAssessor	Benign	1.1	L
PhyloP100		1.8
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-1.8	N
REVEL	Uncertain	0.61
Sift	Benign	0.19	T
Sift4G	Benign	0.22	T
Polyphen		0.053	B
Vest4		0.27
MutPred		0.50		Gain of helix (P = 0.132)
MVP		0.90
MPC		0.21
ClinPred		0.17	T
GERP RS		4.1
Varity_R		0.076
gMVP		0.68
Mutation Taster		=80/20	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
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

Other links and lift over

dbSNP: rs199517389; hg19: chr11-111959676;