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

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000083 ( 0 hom. )

Consequence

ALDH7A1
NM_001182.5 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 5.88
Variant links:
Genes affected
ALDH7A1 (HGNC:877): (aldehyde dehydrogenase 7 family member A1) The protein encoded by this gene is a member of subfamily 7 in the aldehyde dehydrogenase gene family. These enzymes are thought to play a major role in the detoxification of aldehydes generated by alcohol metabolism and lipid peroxidation. This particular member has homology to a previously described protein from the green garden pea, the 26g pea turgor protein. It is also involved in lysine catabolism that is known to occur in the mitochondrial matrix. Recent reports show that this protein is found both in the cytosol and the mitochondria, and the two forms likely arise from the use of alternative translation initiation sites. An additional variant encoding a different isoform has also been found for this gene. Mutations in this gene are associated with pyridoxine-dependent epilepsy. Several related pseudogenes have also been identified. [provided by RefSeq, Jan 2011]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 5-126545020-C-A is Pathogenic according to our data. Variant chr5-126545020-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 374140.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr5-126545020-C-A is described in Lovd as [Pathogenic]. Variant chr5-126545020-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ALDH7A1NM_001182.5 linkc.1566-1G>T splice_acceptor_variant, intron_variant Intron 17 of 17 ENST00000409134.8 NP_001173.2 P49419-1
ALDH7A1NM_001201377.2 linkc.1482-1G>T splice_acceptor_variant, intron_variant Intron 17 of 17 NP_001188306.1 P49419-2
ALDH7A1NM_001202404.2 linkc.1374-1G>T splice_acceptor_variant, intron_variant Intron 15 of 15 NP_001189333.2 P49419-4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ALDH7A1ENST00000409134.8 linkc.1566-1G>T splice_acceptor_variant, intron_variant Intron 17 of 17 1 NM_001182.5 ENSP00000387123.3 P49419-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152110
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000159
AC:
4
AN:
250932
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135692
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000353
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000826
AC:
12
AN:
1451974
Hom.:
0
Cov.:
29
AF XY:
0.00000968
AC XY:
7
AN XY:
722978
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000109
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152110
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74300
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.00000834
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pyridoxine-dependent epilepsy Pathogenic:3
Aug 29, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Nov 05, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 11, 2023
Genome-Nilou Lab
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Pathogenic:2
Oct 31, 2023
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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) -

Jan 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Seizure;C3278923:Ventriculomegaly Pathogenic:1
Jan 15, 2015
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Pyridoxine-dependent epilepsy caused by ALDH7A1 mutant Pathogenic:1
Sep 04, 2023
Molecular Genetics, Royal Melbourne Hospital
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Jan 02, 2024
PreventionGenetics, part of Exact Sciences
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.53
D
BayesDel_noAF
Pathogenic
0.21
CADD
Pathogenic
31
DANN
Uncertain
0.99
Eigen
Pathogenic
0.98
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Pathogenic
0.99
D
GERP RS
4.3

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
0.78
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.78
Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs140845195; hg19: chr5-125880712; API