NM_004937.3:c.771_793delGGGAGTGACCACGTGGCTGCAGT
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_004937.3(CTNS):c.771_793delGGGAGTGACCACGTGGCTGCAGT(p.Gly258SerfsTer30) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000093 in 1,612,260 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_004937.3 frameshift
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CTNS | NM_004937.3 | c.771_793delGGGAGTGACCACGTGGCTGCAGT | p.Gly258SerfsTer30 | frameshift_variant | Exon 10 of 12 | ENST00000046640.9 | NP_004928.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 152072Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000279 AC: 7AN: 251296 AF XY: 0.0000294 show subpopulations
GnomAD4 exome AF: 0.00000890 AC: 13AN: 1460070Hom.: 0 AF XY: 0.0000110 AC XY: 8AN XY: 726384 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152190Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74420 show subpopulations
ClinVar
Submissions by phenotype
Nephropathic cystinosis Pathogenic:6
This 23 bp deletion in CTNS has been previously reported in individuals with nephropathic cystinosis. This CTNS variant (rs759623796) is rare (<0.1%) in a large population dataset (gnomAD: 7/251296 total alleles; 0.003%; no homozygotes) and there is an entry in ClinVar. This frameshift variant results in a premature stop codon in exon 11 likely leading to nonsense-mediated decay and lack of protein production. We consider this variant to be pathogenic. -
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
Variant summary: CTNS c.771_793del23 (p.Gly258SerfsX30) 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. The variant allele was found at a frequency of 2.8e-05 in 251296 control chromosomes. c.771_793del23 has been reported in the literature in individuals affected with Nephropathic cystinosis. These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 10556299, 26266097). ClinVar contains an entry for this variant (Variation ID: 496276). Based on the evidence outlined above, the variant was classified as pathogenic. -
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The observed frameshift c.771_793del (p.Gly258SerfsTer30) variant in CTNS gene has been reported in homozygous state in individual(s) affected with cystinosis (Chkioua L et al., 2015; Ghazi F, et. al., 2017). The p.Gly258SerfsTer30 variant is present with allele frequency 0.003% in gnomAD Exomes database. This variant has been submitted to the ClinVar database as Likely Pathogenic / Pathogenic (multiple submitters). This variant causes a frameshift starting with codon Glycine 258, changes this amino acid to Serine residue, and creates a premature Stop codon at position 30 of the new reading frame, denoted p.Gly258SerfsTer30. This variant is predicted to cause loss of normal protein function through protein truncation. Loss-of-function variants in CTNS are known to be pathogenic (Elmonem MA, et. al., 2016). For these reasons, this variant has been classified as Pathogenic. -
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Cystinosis Pathogenic:2
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Juvenile nephropathic cystinosis;C2931013:Ocular cystinosis;C2931187:Nephropathic cystinosis Pathogenic:1
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not provided Pathogenic:1
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Juvenile nephropathic cystinosis;C0950123:Inborn genetic diseases;C2931013:Ocular cystinosis Pathogenic:1
This sequence change creates a premature translational stop signal (p.Gly258Serfs*30) 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 present in population databases (rs759623796, gnomAD 0.02%). This premature translational stop signal has been observed in individuals with cystinosis (PMID: 10556299, 26266097). This variant is also known as c.1109_1131del23. ClinVar contains an entry for this variant (Variation ID: 496276). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at