11-65206824-G-A
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PP3_ModeratePP5_Very_Strong
The NM_005186.4(CAPN1):c.1605+5G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000106 in 1,610,740 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_005186.4 splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive spastic paraplegia type 76Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
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ACMG classification
Our verdict: Pathogenic. The variant received 10 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000125 AC: 19AN: 152054Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000116 AC: 28AN: 242366 AF XY: 0.000137 show subpopulations
GnomAD4 exome AF: 0.000104 AC: 151AN: 1458686Hom.: 0 Cov.: 32 AF XY: 0.000110 AC XY: 80AN XY: 725384 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000125 AC: 19AN: 152054Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5AN XY: 74280 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal recessive spastic paraplegia type 76 Pathogenic:10
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Variant summary: CAPN1 c.1605+5G>A alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes a 5' splicing donor site. Two predict the variant weakens a 5' donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing, showing the variant leads to skipping of exon 14, confirmed by cDNA sequencing (e.g. Gan-Or_2016). The variant allele was found at a frequency of 0.00012 in 242366 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CAPN1 causing Autosomal Recessive Spastic Paraplegia Type 76, allowing no conclusion about variant significance. c.1605+5G>A has been reported in the literature in homozygous and compound heterozygous individuals affected with Autosomal Recessive Spastic Paraplegia Type 76 (e.g. Gan-Or_2016, Benkirane_2021, Ek_2023), or in one compound heterozygous individual affected with a spinocerebellar ataxia (e.g. Baviera-Muoz_2022). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 34234304, 37273706, 36530930, 27153400). ClinVar contains an entry for this variant (Variation ID: 225768). Based on the evidence outlined above, the variant was classified as pathogenic. -
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The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.011%). Predicted Consequence/Location: Intron variant In silico tools predict the variant to alter splicing and produce an abnormal transcript [SpliceAI: 0.56 (>=0.2, moderate evidence for spliceogenicity)]. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000225768 /PMID: 27153400). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
not provided Pathogenic:3
Non-canonical splice site variant demonstrated to result in loss-of-function (Gan-Or et al., 2016); This variant is associated with the following publications: (PMID: 30572172, 27153400, 32214227, 33726816, 33486633) -
DNA sequence analysis of the CAPN1 gene demonstrated a sequence change located near the canonical splice donor site in intron 14, c.1605+5G>A. This sequence change has been described in the gnomAD database with a low population frequency of 0.012% (dbSNP rs375817528). This variant was identified in two symptomatic family members with spastic paraplegia in a compound heterozygous state with other frameshift variant (Gan-Or et al., 2016). Based on in silico splice prediction programs, this sequence change likely affects normal splicing of the CAPN1 gene, which would result in an abnormal protein, however functional studies have not been performed to prove this conclusively. -
This sequence change falls in intron 14 of the CAPN1 gene. It does not directly change the encoded amino acid sequence of the CAPN1 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (rs375817528, gnomAD 0.02%). This variant has been observed in individual(s) with hereditary spastic paraplegia (PMID: 27153400, 32214227, 33486633; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 225768). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 14, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 27153400). 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