rs587777616
Variant summary
Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong
The NM_006831.3(CLP1):c.419G>A(p.Arg140His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000178 in 1,461,864 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 Likely pathogenic (★★).
Frequency
Consequence
NM_006831.3 missense
Scores
Clinical Significance
Conservation
Publications
- pontocerebellar hypoplasia type 10Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), PanelApp Australia
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ACMG classification
Our verdict: Pathogenic. The variant received 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251204 AF XY: 0.00000737 show subpopulations
GnomAD4 exome AF: 0.0000178 AC: 26AN: 1461864Hom.: 0 Cov.: 32 AF XY: 0.0000220 AC XY: 16AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Pontocerebellar hypoplasia type 10 Pathogenic:6
The missense variant p.R140H in CLP1 (NM_006831.3) has been reported in multiple individuals of Turkish origin and has been classified as a Founder variant in the same population (Schaffer AE et al). Functional studies revealed a damaging effect. The variant has been submitted to ClinVar as Pathogenic. The p.R140H missense variant is predicted to be damaging by both SIFT and PolyPhen2. The arginine residue at codon 140 of CLP1 is conserved in all mammalian species. The nucleotide c.419 in CLP1 is predicted conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Pathogenic -
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Criteria applied: PP1_STR,PS3_MOD,PM3,PM2_SUP,PP3 -
The homozygous p.Arg140His variant in CLP1 was identified by our study in one individual with pontocerebellar hypoplasia. This variant has been identified in 0.002978% (1/33574) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs587777616). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. The homozygous p.Arg140His variant in CLP1 has been reported in 19 Turkish individuals with cerebellar abnormalities and segregated with disease in 19 affected relatives from 9 families (PMID: 24766809, 24766810). In vitro functional studies provide some evidence that the p.Arg140His variant may impact protein function by impairing protein interaction with TSEN and reducing pre-tRNA cleavage activity. Northern blot analysis of individuals homozygous and heterozygous for this variant demonstrated increased levels of linear tRNA introns in individuals with the variant in the homozygous state (PMID: 24766809, 24766810). However, these types of assays may not accurately represent biological function. Animal models in zebrafish have shown that the wildtype gene, but not this variant, can rescue cerebellar neurodegeneration and animal models in mice have shown that this variant casues pontocerebellar hypoplasia (PMID: 24766809, 24766810). In summary, this variant meets criteria to be classified as pathogenic for Pontocerebellar Hypoplasia in an autosomal recessive manner based on evidence from in vitro functional studies, animal models in mice and zebrafish, and multiple occurrences of cosegregation in Turkish families. ACMG/AMP Criteria applied: PM2, PS3, PP1_Strong, PP3 (Richards 2015). -
The R140H variant in CLP1 gene has been identified in two Iranian families with seizure, brain and cerebellar atrophy, leukodystrophy, hypotonia, and developmental and motor delay. -
not provided Pathogenic:4
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CLP1: PP1:Strong, PM2, PM3, PS3:Moderate -
Published functional studies demonstrate a damaging effect on protein function (PMID: 35139363, 24766809, 24766810); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 29307788, 24766809, 24766810, 34548404, 38622473, 34273619, 35156311, 25142875, 32143824, Ozcora2020[article], 34791078, 33337366, 38925092, 34584079, 37231152, 35139363, 36076253, 35719383, 38347586, 28097321, 34582790, Ibrahimoglu2024[abstract]) -
Pontoneocerebellar hypoplasia Pathogenic:1
Variant summary: CLP1 c.419G>A (p.Arg140His) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 4e-06 in 251204 control chromosomes. c.419G>A has been observed at a homozygous state in multiple families affected with progressive brain atrophy, cerebellar development delay and neurodegeneration (example, Schaffer_2014). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in less than 50% of normal activity in vitro (Schaffer_2014). The following publication has been ascertained in the context of this evaluation (PMID: 24766810). ClinVar contains an entry for this variant (Variation ID: 143934). Based on the evidence outlined above, the variant was classified as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at