rs760256854

Positions:

• chr17-3656724-AACG-A

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM4_Supporting PP5_Very_Strong

The NM_004937.3(CTNS):​c.614_616del​(p.Asp205del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,238 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. N204N) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 29)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: CTNS NM_004937.3 inframe_deletion
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 7.42

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-AS1 (HGNC:56090): (CTNS antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_004937.3
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_004937.3. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 17-3656724-AACG-A is Pathogenic according to our data. Variant chr17-3656724-AACG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188718.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CTNS	NM_004937.3	c.614_616del	p.Asp205del	inframe_deletion	9/12	ENST00000046640.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CTNS	ENST00000046640.9	c.614_616del	p.Asp205del	inframe_deletion	9/12	1	NM_004937.3	P1
CTNS-AS1	ENST00000575741.1	n.532+129_532+131del		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151740 Hom.: 0 Cov.: 29

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000657

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

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251348 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135908

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000163

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000753 AC: 11 AN: 1461498 Hom.: 0 AF XY: 0.00000963 AC XY: 7 AN XY: 727064

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151740 Hom.: 0 Cov.: 29 AF XY: 0.0000135 AC XY: 1 AN XY: 74088

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000657

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Nephropathic cystinosis Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 23, 2024	- -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Mar 12, 2014	- -

Cystinosis Pathogenic:1 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 25, 2022	Variant summary: CTNS c.614_616delACG (p.Asp205del) results in an in-frame deletion that is predicted to remove one amino acid from the encoded protein. The variant allele was found at a frequency of 1.2e-05 in 251348 control chromosomes. c.614_616delACG has been reported in the literature in individuals affected with Cystinosis in homozygous and compound heterozygous states. These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided, no classification provided	literature only	GeneReviews	-	- -

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 11, 2023

This variant is present in population databases (rs760256854, gnomAD 0.01%). This variant, c.614_616del, results in the deletion of 1 amino acid(s) of the CTNS protein (p.Asp205del), but otherwise preserves the integrity of the reading frame. This variant has been observed in individual(s) with cystinosis (PMID: 9792862, 10556299). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the CTNS protein in which other variant(s) (p.Asp205Asn) have been determined to be pathogenic (PMID: 9792862, 22528245, 28983406). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. Experimental studies have shown that this variant affects CTNS function (PMID: 15128704). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. ClinVar contains an entry for this variant (Variation ID: 188718). -

Computational scores

Source: dbNSFP v4.3

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: rs760256854; hg19: chr17-3560018;