rs376917645
Variant summary
Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM5PP2PP3_ModeratePP5
The NM_001182.5(ALDH7A1):c.575C>T(p.Thr192Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,040 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. T192K) has been classified as Likely pathogenic.
Frequency
Consequence
NM_001182.5 missense
Scores
Clinical Significance
Conservation
Publications
- pyridoxine-dependent epilepsyInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Illumina, Orphanet, ClinGen
- pyridoxine-dependent epilepsy caused by ALDH7A1 mutantInheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 8 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| ALDH7A1 | NM_001182.5 | c.575C>T | p.Thr192Met | missense_variant | Exon 6 of 18 | ENST00000409134.8 | NP_001173.2 | |
| ALDH7A1 | NM_001201377.2 | c.491C>T | p.Thr164Met | missense_variant | Exon 6 of 18 | NP_001188306.1 | ||
| ALDH7A1 | NM_001202404.2 | c.575C>T | p.Thr192Met | missense_variant | Exon 6 of 16 | NP_001189333.2 | 
Ensembl
Frequencies
GnomAD3 genomes  0.0000131  AC: 2AN: 152154Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000119  AC: 3AN: 251476 AF XY:  0.0000147   show subpopulations 
GnomAD4 exome  AF:  0.00000616  AC: 9AN: 1461886Hom.:  0  Cov.: 31 AF XY:  0.00000825  AC XY: 6AN XY: 727244 show subpopulations 
Age Distribution
GnomAD4 genome  0.0000131  AC: 2AN: 152154Hom.:  0  Cov.: 32 AF XY:  0.0000269  AC XY: 2AN XY: 74326 show subpopulations  ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. 
Age Distribution
ClinVar
Submissions by phenotype
Pyridoxine-dependent epilepsy    Pathogenic:3 
This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 192 of the ALDH7A1 protein (p.Thr192Met). This variant is present in population databases (rs376917645, gnomAD 0.007%). This missense change has been observed in individual(s) with epilepsy (PMID: 29655203; 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: 265033). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ALDH7A1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
Variant summary: ALDH7A1 c.575C>T (p.Thr192Met) results in a non-conservative amino acid change located in the Aldehyde dehydrogenase domain (IPR015590) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251476 control chromosomes (gnomAD). c.575C>T has been reported in the literature in individuals affected with Pyridoxine-Dependent Epilepsy (Lindy_2018, Couglin_2019, GIbaud_2021). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 29655203, 30043187, 33748042). ClinVar contains an entry for this variant (Variation ID: 265033). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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not provided    Pathogenic:1Uncertain:1 
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Reported in a patient with epilepsy and/or a neurodevelopmental disorder, but additional information was not provided (PMID: 29655203); Not observed at a 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: 32956737, 30043187, 34426522, 29655203) -
ALDH7A1-related disorder    Pathogenic:1 
The ALDH7A1 c.575C>T variant is predicted to result in the amino acid substitution p.Thr192Met. This variant has been reported in multiple individuals with epilepsy and/or neurodevelopmental disorders (Lindy et al. 2018. PubMed ID: 29655203, table S4; Coughlin et al. 2019. PubMed ID: 30043187, Supp Table II). It was reported in the compound heterozygous state with a pathogenic variant in two individual in the literature (Coughlin CR 2nd et al. 2019. PubMed ID: 30043187, Supp Table II) and by a diagnostic lab in ClinVar, where it has classifications of uncertain and pathogenic (https://www.ncbi.nlm.nih.gov/clinvar/variation/265033/). This variant is reported in 0.0062% of alleles in individuals of African descent in gnomAD. Taken together, we classify this variant to be likely pathogenic. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at