rs1475322504

Positions:

• chr17-3659856-A-G

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.853-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000685 in 1,459,462 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CTNS NM_004937.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 6.81

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 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-3659856-A-G is Pathogenic according to our data. Variant chr17-3659856-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 496277.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CTNS	NM_004937.3	c.853-2A>G		splice_acceptor_variant, intron_variant		ENST00000046640.9	NP_004928.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CTNS	ENST00000046640.9	c.853-2A>G		splice_acceptor_variant, intron_variant		1	NM_004937.3	ENSP00000046640.4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250630 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135706

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459462 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726182

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: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Nephropathic cystinosis Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Apr 18, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 17, 2023	- -

Cystinosis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Feb 02, 2017

Variant summary: The CTNS c.853-2A>G variant involves the alteration of a conserved intronic nucleotide. One in silico tool predicts a damaging outcome for this variant. 4/4 splice prediction tools predict the complete loss of a canonical 5' splice acceptor site. These predictions have been confired by functional studies showing patient RNA having a transcript that contains the first 41bp of IVS10 and a deletion of the first 26 bp of exon11. This variant is absent in 118932 control chromosomes but has been reported in a severely affected proband in the literature. Taken together, this variant is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.97	D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.62		Position offset: 28
DS_AL_spliceai		0.99		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1475322504; hg19: chr17-3563150;