chr17-3655288-A-T

Variant names:

• chr17-3655288-A-T
• rs886040970
• NM_004937.3:c.397A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_004937.3(CTNS):​c.397A>T​(p.Ile133Phe) 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 not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I133M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CTNS NM_004937.3 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 4.49
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• cystinosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
• nephropathic cystinosis

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Ambry Genetics
• juvenile nephropathic cystinosis

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)
• ocular cystinosis

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• nephropathic infantile cystinosis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in NM_004937.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.944

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004937.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTNS	NM_004937.3	MANE Select	c.397A>T	p.Ile133Phe	missense	Exon 7 of 12	NP_004928.2	O60931-1
	CTNS	NM_001031681.3		c.397A>T	p.Ile133Phe	missense	Exon 7 of 13	NP_001026851.2	O60931-2
	CTNS	NM_001374492.1		c.397A>T	p.Ile133Phe	missense	Exon 7 of 13	NP_001361421.1	O60931-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTNS	ENST00000046640.9	TSL:1 MANE Select	c.397A>T	p.Ile133Phe	missense	Exon 7 of 12	ENSP00000046640.4	O60931-1
	CTNS	ENST00000381870.8	TSL:1	c.397A>T	p.Ile133Phe	missense	Exon 7 of 13	ENSP00000371294.3	O60931-2
	CTNS	ENST00000673965.1		c.397A>T	p.Ile133Phe	missense	Exon 7 of 12	ENSP00000500995.1	O60931-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 50

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: not provided

Revision: no classification provided

Pathogenic	VUS	Benign	Condition
-	-	-	Cystinosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.95	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		4.5
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-3.3	D
REVEL	Pathogenic	0.93
Sift	Benign	0.036	D
Sift4G	Uncertain	0.047	D
Polyphen		0.99	D
Vest4		0.83
MutPred		0.85		Loss of catalytic residue at I133 (P = 0.0372)
MVP		1.0
MPC		0.83
ClinPred		0.98	D
GERP RS		5.2
Varity_R		0.55
gMVP		0.86
Mutation Taster		=9/91	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs886040970; hg19: chr17-3558582;