chr11-6616374-C-T
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PM5PP3_ModeratePP5
The NM_000391.4(TPP1):c.1016G>A(p.Arg339Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R339L) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000391.4 missense
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
Genome browser will be placed here
ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000391.4. 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 |
|---|---|---|---|---|---|---|---|---|---|
| TPP1 | NM_000391.4 | MANE Select | c.1016G>A | p.Arg339Gln | missense | Exon 8 of 13 | NP_000382.3 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TPP1 | ENST00000299427.12 | TSL:1 MANE Select | c.1016G>A | p.Arg339Gln | missense | Exon 8 of 13 | ENSP00000299427.6 | ||
| TPP1 | ENST00000533371.6 | TSL:1 | c.287G>A | p.Arg96Gln | missense | Exon 7 of 12 | ENSP00000437066.1 | ||
| TPP1 | ENST00000682424.1 | c.902G>A | p.Arg301Gln | missense | Exon 7 of 12 | ENSP00000507321.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152140Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251446 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000821 AC: 12AN: 1461626Hom.: 0 Cov.: 90 AF XY: 0.00000275 AC XY: 2AN XY: 727126 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152140Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74338 show subpopulations
ClinVar
Submissions by phenotype
not provided Pathogenic:4Uncertain:1
Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 32298681, 30541466, 29056246, 23266810, 21990111, 19038966)
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 339 of the TPP1 protein (p.Arg339Gln). This variant is present in population databases (rs765380155, gnomAD 0.0009%). This missense change has been observed in individual(s) with TPP1-related conditions (PMID: 22832778, 23266810). ClinVar contains an entry for this variant (Variation ID: 198725). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TPP1 protein function with a positive predictive value of 95%. This variant disrupts the p.Pro339 amino acid residue in TPP1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 24091540; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.
Neuronal ceroid lipofuscinosis 2 Pathogenic:4
We confirmed the missense variation NC_00011.10:g.6616374C>T (NP_000382.3:p.Arg339Gln; rs765380155) in exon 8 of TPP1 gene, segregating with disease in family and in silico analyses predicted the variant to be highly pathogenic that corelated with pathologically low enzymatic activity of TPP1 in the proband's blood sample (<0.49 μmol/L/h; pathological reference = <0.5 μmol/L/h). Reference source OMIM: 204500 Neuronal ceroid lipofuscinosis-2 is caused by homozygous or compound heterozygous mutation in the TPP1 gene (607998) on chromosome 11p15. Reference source ClinVar: RCV000699225.1 NM_000391.4(TPP1):c.1016G>A (p.Arg339Gln) and Neuronal ceroid lipofuscinosis https://www.ncbi.nlm.nih.gov/clinvar/RCV000699225.1/
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at