rs879758262

chr17-3648911-ATCCTT-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004937.3(CTNS):c.206_210del(p.Ile69ArgfsTer5) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000186 in 1,613,190 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. I69I) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CTNS NM_004937.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 5.11

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]

LOC105371493 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-3648911-ATCCTT-A is Pathogenic according to our data. Variant chr17-3648911-ATCCTT-A is described in ClinVar as [Pathogenic]. Clinvar id is 455787.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-3648911-ATCCTT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CTNS	NM_004937.3	c.206_210del	p.Ile69ArgfsTer5	frameshift_variant	5/12	ENST00000046640.9
LOC105371493	XR_007065579.1	n.1934+1248_1934+1252del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CTNS	ENST00000046640.9	c.206_210del	p.Ile69ArgfsTer5	frameshift_variant	5/12	1	NM_004937.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460968 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 726880

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152222 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74374

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Nephropathic cystinosis Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 01, 1998	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 02, 2022	- -

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 27, 2024

This sequence change creates a premature translational stop signal (p.Ile69Argfs*5) in the CTNS gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CTNS are known to be pathogenic (PMID: 9537412, 27102039). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with cystinosis (PMID: 10625078). ClinVar contains an entry for this variant (Variation ID: 455787). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Cystinosis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Mar 30, 2021

Variant summary: CTNS c.206_210delTCCTT (p.Ile69ArgfsX5) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251456 control chromosomes. c.206_210delTCCTT has been reported as a homozygous mutation in at least one individual affected with Cystinosis (e.g. Shotelersuk_1998). These data indicate that the variant may be associated with disease. Fibroblasts from this patient were assessed as having higher levels of intracellular cystine compared to normal controls (e.g. Vitcitsky_2010). One other clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and cited the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs879758262; hg19: chr17-3552205;