chr17-3647455-A-G

Variant names:

• chr17-3647455-A-G
• rs777367316
• NM_004937.3:c.73A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_004937.3(CTNS):​c.73A>G​(p.Ser25Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,772 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S25C) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CTNS NM_004937.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.372
• Publications: 0 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: Myriad Women’s Health
• nephropathic cystinosis

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

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

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

LOC105371493 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-3647455-A-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 555150.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.07173872).

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTNS	NM_004937.3	MANE Select	c.73A>G	p.Ser25Gly	missense	Exon 4 of 12	NP_004928.2
	CTNS	NM_001031681.3		c.73A>G	p.Ser25Gly	missense	Exon 4 of 13	NP_001026851.2
	CTNS	NM_001374492.1		c.73A>G	p.Ser25Gly	missense	Exon 4 of 13	NP_001361421.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTNS	ENST00000046640.9	TSL:1 MANE Select	c.73A>G	p.Ser25Gly	missense	Exon 4 of 12	ENSP00000046640.4
	CTNS	ENST00000381870.8	TSL:1	c.73A>G	p.Ser25Gly	missense	Exon 4 of 13	ENSP00000371294.3
	CTNS	ENST00000673965.1		c.73A>G	p.Ser25Gly	missense	Exon 4 of 12	ENSP00000500995.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251446 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000137 AC: 2 AN: 1461772 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727196

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53406

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111912

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000165 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.071
BayesDel_addAF	Benign	-0.094	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	6.4
DANN	Benign	0.80
DEOGEN2	Benign	0.26	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.037	N
LIST_S2	Benign	0.45	T
M_CAP	Benign	0.035	D
MetaRNN	Benign	0.072	T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Benign	1.7	L
PhyloP100		-0.37
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-1.2	N
REVEL	Benign	0.23
Sift	Benign	0.22	T
Sift4G	Benign	0.39	T
Polyphen		0.0	B
Vest4		0.13
MutPred		0.24		Loss of stability (P = 0.0079)
MVP		0.67
MPC		0.15
ClinPred		0.041	T
GERP RS		-6.3
Varity_R		0.045
gMVP		0.39

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

Other links and lift over

dbSNP: rs777367316; hg19: chr17-3550749;