rs121908126

Positions:

• chr17-3656531-G-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_004937.3(CTNS):​c.506G>A​(p.Gly169Asp) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 27)
• Consequence: CTNS NM_004937.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 6.42

Genes affected

CTNS (HGNC:2518): (cystinosin, lysosomal cystine transporter) This gene encodes a seven-transmembrane domain protein that functions to transport cystine out of lysosomes. Its activity is driven by the H+ electrochemical gradient of the lysosomal membrane. Mutations in this gene cause cystinosis, a lysosomal storage disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2009]

CTNS (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a transmembrane_region Helical (size 20) in uniprot entity CTNS_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_004937.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 17-3656531-G-A is Pathogenic according to our data. Variant chr17-3656531-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 4446.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr17-3656531-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CTNS	NM_004937.3	c.506G>A	p.Gly169Asp	missense_variant	8/12	ENST00000046640.9	NP_004928.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CTNS	ENST00000046640.9	c.506G>A	p.Gly169Asp	missense_variant	8/12	1	NM_004937.3	ENSP00000046640.4

Frequencies

GnomAD3 genomes Cov.: 27

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 27

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Nephropathic cystinosis Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 1998

- -

Juvenile nephropathic cystinosis;C0950123:Inborn genetic diseases;C2931013:Ocular cystinosis Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 01, 2021

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 169 of the CTNS protein (p.Gly169Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with cystinosis (PMID: 9792862). This variant is also known as 845G>A. ClinVar contains an entry for this variant (Variation ID: 4446). 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 expected to disrupt CTNS protein function. Experimental studies have shown that this missense change affects CTNS function (PMID: 15128704). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.5	H;H;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-6.7	D;D;.
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D;.
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.99
MutPred		0.94		Gain of relative solvent accessibility (P = 0.0479);Gain of relative solvent accessibility (P = 0.0479);.;
MVP		0.99
MPC		0.78
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.98
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121908126; hg19: chr17-3559825;