11-6617154-C-T
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000391.4(TPP1):c.509-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000266 in 1,614,098 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 Pathogenic (★★).
Frequency
Consequence
NM_000391.4 splice_acceptor, intron
Scores
Clinical Significance
Conservation
Publications
- neuronal ceroid lipofuscinosisInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- neuronal ceroid lipofuscinosis 2Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Myriad Women’s Health, G2P, Orphanet
- autosomal recessive spinocerebellar ataxia 7Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TPP1 | NM_000391.4 | c.509-1G>A | splice_acceptor_variant, intron_variant | Intron 5 of 12 | ENST00000299427.12 | NP_000382.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TPP1 | ENST00000299427.12 | c.509-1G>A | splice_acceptor_variant, intron_variant | Intron 5 of 12 | 1 | NM_000391.4 | ENSP00000299427.6 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152114Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251364 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.0000287 AC: 42AN: 1461866Hom.: 0 Cov.: 41 AF XY: 0.0000303 AC XY: 22AN XY: 727242 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152232Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74436 show subpopulations
ClinVar
Submissions by phenotype
not provided Pathogenic:3
This sequence change affects an acceptor splice site in intron 5 of the TPP1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs56144125, gnomAD 0.003%). Disruption of this splice site has been observed in individual(s) with neuronal ceroid lipofuscinosis (PMID: 10330339, 10356316, 22832778). This variant is also known as c.3556G>A and T523-1G>A. ClinVar contains an entry for this variant (Variation ID: 207574). Studies have shown that disruption of this splice site results in activation of a cryptic splice site and introduces a premature termination codon (PMID: 10356316). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -
Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 26143525, 22344438, 10356316, 10330339, 21940688, 31440721, 21990111) -
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Neuronal ceroid lipofuscinosis 2 Pathogenic:2
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. -
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Autosomal recessive spinocerebellar ataxia 7;C1876161:Neuronal ceroid lipofuscinosis 2 Pathogenic:1
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Inborn genetic diseases Pathogenic:1
The c.509-1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide upstream from coding exon 6 of the TPP1 gene. This mutation (reported as T523-1G>A or 3556G>A) has been reported in multiple unrelated individuals with late-infantile neuronal ceroid lipofuscinosis (NCL) who carried a second mutation (Hartikainen JM et al. Mol. Genet. Metab., 1999 Jun;67:162-8; Sleat DE et al. Am. J. Hum. Genet., 1999 Jun;64:1511-23). In addition, analysis of mRNA from one patient revealed that this mutation resulted in an insertion of the adjacent intronic sequence (Hartikainen JM et al. Mol. Genet. Metab., 1999 Jun;67:162-8). A different alteration at the same position (c.509-1G>C), resulting in the same aberrant splicing, is also one of the most common mutations associated with NCL. In addition to these data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -
Neuronal ceroid lipofuscinosis Pathogenic:1
Variant summary: TPP1 c.509-1G>A is a splice-site variant that alters a conserved nucleotide. 5/5 in silico tools via Alamut predict this variant to disrupt a canonical acceptor sequence, which has been confirmed by Hartikainen et al (1999) who showed an aberrant splicing pattern. It has been reported in multiple affected individuals with LINCL with nearly absent residual enzyme activity (Perez-Poyato_JCN_2012 and Hartikainen_MGM_1999, respectively). The variant is present in ExAC at low frequency (0.0025%) which does not exceed the maximum frequency for a pathogenic variant in TPP1 gene (0.29%). Lastly, it has been classified as pathogenic via publications and/or reputable databases/clinical laboratories. Taken together, the variant was classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at