rs201869920

chr1-243308026-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_006642.5(SDCCAG8):c.778C>G(p.Leu260Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000734 in 1,614,102 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00049 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00076 (0 hom.)
• Consequence: SDCCAG8 NM_006642.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:1
• Conservation: PhyloP100: 0.850

Genes affected

SDCCAG8 (HGNC:10671): (SHH signaling and ciliogenesis regulator SDCCAG8) This gene encodes a centrosome associated protein. This protein may be involved in organizing the centrosome during interphase and mitosis. Mutations in this gene are associated with retinal-renal ciliopathy. [provided by RefSeq, Oct 2010]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.016725808).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDCCAG8	NM_006642.5	c.778C>G	p.Leu260Val	missense_variant	8/18	ENST00000366541.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDCCAG8	ENST00000366541.8	c.778C>G	p.Leu260Val	missense_variant	8/18	1	NM_006642.5	P1
SDCCAG8	ENST00000435549.1	c.118C>G	p.Leu40Val	missense_variant	3/11	1
SDCCAG8	ENST00000463012.1	n.138C>G		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes AF: 0.000486 AC: 74 AN: 152204 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00173

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000621

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000601 AC: 151 AN: 251328 Hom.: 0 AF XY: 0.000604 AC XY: 82 AN XY: 135840

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000260

Gnomad ASJ exome AF: 0.00169

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000751

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000871

Gnomad OTH exome AF: 0.000489

GnomAD4 exome AF: 0.000759 AC: 1110 AN: 1461780 Hom.: 0 Cov.: 33 AF XY: 0.000749 AC XY: 545 AN XY: 727194

Gnomad4 AFR exome AF: 0.0000896

Gnomad4 AMR exome AF: 0.000335

Gnomad4 ASJ exome AF: 0.00157

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000777

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000842

Gnomad4 OTH exome AF: 0.000662

GnomAD4 genome AF: 0.000486 AC: 74 AN: 152322 Hom.: 0 Cov.: 33 AF XY: 0.000416 AC XY: 31 AN XY: 74468

Gnomad4 AFR AF: 0.0000240

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00173

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000621

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000680 Hom.: 0

Bravo AF: 0.000427

TwinsUK AF: 0.00162 AC: 6

ALSPAC AF: 0.000519 AC: 2

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000349 AC: 3

ExAC AF: 0.000412 AC: 50

Asia WGS AF: 0.00115 AC: 4 AN: 3478

EpiCase AF: 0.000654

EpiControl AF: 0.000652

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Sep 27, 2016

- -

Kidney disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

May 10, 2017

- -

Senior-Loken syndrome 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Senior-Loken syndrome 7;C3889474:Bardet-Biedl syndrome 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 18, 2022

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 260 of the SDCCAG8 protein (p.Leu260Val). This variant is present in population databases (rs201869920, gnomAD 0.2%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with SDCCAG8-related conditions. ClinVar contains an entry for this variant (Variation ID: 436676). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SDCCAG8 protein function. 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. -

Bardet-Biedl syndrome 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

SDCCAG8-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Sep 02, 2020

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.18
Cadd	Benign	21
Dann	Uncertain	0.99
DEOGEN2	Benign	0.051	T;T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Benign	0.72	D
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.017	T;T
MetaSVM	Benign	-0.65	T
MutationAssessor	Uncertain	2.5	M;.
MutationTaster	Benign	0.86	D;D;D;D
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-1.8	N;N
REVEL	Benign	0.16
Sift	Uncertain	0.010	D;D
Sift4G	Benign	0.16	T;T
Polyphen		0.96	D;.
Vest4		0.30
MVP		0.54
MPC		0.21
ClinPred		0.087	T
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.15
gMVP		0.18

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

Publications

LitVar

Other links and lift over

dbSNP: rs201869920; hg19: chr1-243471328;