rs140845195
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_001182.5(ALDH7A1):c.1566-1G>T variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000873 in 1,604,084 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_001182.5 splice_acceptor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
ALDH7A1 | NM_001182.5 | c.1566-1G>T | splice_acceptor_variant, intron_variant | Intron 17 of 17 | ENST00000409134.8 | NP_001173.2 | ||
ALDH7A1 | NM_001201377.2 | c.1482-1G>T | splice_acceptor_variant, intron_variant | Intron 17 of 17 | NP_001188306.1 | |||
ALDH7A1 | NM_001202404.2 | c.1374-1G>T | splice_acceptor_variant, intron_variant | Intron 15 of 15 | NP_001189333.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152110Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000159 AC: 4AN: 250932Hom.: 0 AF XY: 0.0000221 AC XY: 3AN XY: 135692
GnomAD4 exome AF: 0.00000826 AC: 12AN: 1451974Hom.: 0 Cov.: 29 AF XY: 0.00000968 AC XY: 7AN XY: 722978
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152110Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74300
ClinVar
Submissions by phenotype
Pyridoxine-dependent epilepsy Pathogenic:3
This sequence change affects an acceptor splice site in intron 17 of the ALDH7A1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the loss of 5 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is present in population databases (rs140845195, gnomAD 0.004%). Disruption of this splice site has been observed in individual(s) with pyridoxine dependent epilepsy (PMID: 17068770, 23350806). It has also been observed to segregate with disease in related individuals. This variant is also known as c.1482-1G>T. ClinVar contains an entry for this variant (Variation ID: 374140). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in exon 18 (PMID: 23350806). For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:2
Observed in the homozygous state, with a pathogenic variant on the opposite allele (in trans), or with a second ALDH7A1 variant, phase unknown, in individuals with pyridoxine-dependent epilepsy in the published literature and not observed in homozygous state in controls (PMID: 30043187, 17068770); 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); Previously reported as c.1482-1 G>T due to alternative nomenclature; This variant is associated with the following publications: (PMID: 31589614, 29286531, 31990480, 17068770, 36011376, 30043187, 31440721, 31623504) -
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Seizure;C3278923:Ventriculomegaly Pathogenic:1
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Pyridoxine-dependent epilepsy caused by ALDH7A1 mutant Pathogenic:1
This sequence change in ALDH7A1 occurs within the canonical splice acceptor site of intron 17. It is predicted to cause the activation of the cryptic splice site in exon 18 leading to an in-frame five amino acid deletion (removes amino acids 495-499) which has been confirmed by RT-PCR on patient lymphoblast cells (PMID: 23350806). The highest population minor allele frequency in the population database gnomAD v2.1 is 0.004% (4/113,332 alleles) in the European (non-Finnish) population. This variant has been detected in multiple individuals with pyridoxine-dependent epilepsy, homozygous and compound heterozygous with a second pathogenic variant (PMID: 23350806, 17068770, 31990480, 30043187). Based on the classification scheme RMH Modified ACMG/AMP Guidelines v1.6.1, this variant is classified as PATHOGENIC. Following criteria are met: PVS1_Moderate, PM3_VeryStrong, PM2_Supporting -
ALDH7A1-related disorder Pathogenic:1
The ALDH7A1 c.1566-1G>T variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. This variant has been reported in individuals with pyridoxine-dependent epilepsy (Plecko et al. 2007. PubMed ID: 17068770; Pérez et al. 2013. PubMed ID: 23350806; Coughlin et al. 2019. PubMed ID: 30043187. Table S2). This variant is reported in 0.0035% of alleles in individuals of European (Non-Finnish) descent in gnomAD. Variants that disrupt the consensus splice acceptor site in ALDH7A1 are expected to be pathogenic. This variant is interpreted as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at