rs864622557

Positions:

• chr5-126554294-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The ENST00000409134.8(ALDH7A1):​c.1193G>T​(p.Gly398Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G398R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALDH7A1 ENST00000409134.8 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.86

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in ENST00000409134.8
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr5-126554295-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1067854.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 5-126554294-C-A is Pathogenic according to our data. Variant chr5-126554294-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 220511.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALDH7A1	NM_001182.5	c.1193G>T	p.Gly398Val	missense_variant	13/18	ENST00000409134.8	NP_001173.2
ALDH7A1	NM_001201377.2	c.1109G>T	p.Gly370Val	missense_variant	13/18		NP_001188306.1
ALDH7A1	NM_001202404.2	c.1009-2157G>T		intron_variant			NP_001189333.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALDH7A1	ENST00000409134.8	c.1193G>T	p.Gly398Val	missense_variant	13/18	1	NM_001182.5	ENSP00000387123	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pyridoxine-dependent epilepsy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 06, 2016

This sequence change replaces glycine with valine at codon 398 of the ALDH7A1 protein (p.Gly398Val). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and valine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature. This variant is associated with elevated alpha-AASA in urine in this patient, pyridoxine responsive seizures, and has been confirmed in trans with another pathogenic variant in ALDH7A1 through parental testing. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. A different missense substitution at this codon (p.Gly398Arg) is reported to be deleterious (PMID: 22529283). This indicates that the glycine residue is important for ALDH7A1 protein function. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.36	T;D;T;.;T;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.53	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.3	.;H;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Pathogenic	-8.4	.;D;.;.;.;.;.
REVEL	Pathogenic	0.94
Sift	Uncertain	0.016	.;D;.;.;.;.;.
Sift4G	Pathogenic	0.0010	.;D;.;.;.;.;.
Polyphen		1.0	.;D;.;.;.;.;.
Vest4		0.97
MutPred		0.96		Gain of catalytic residue at G398 (P = 0.0064);Gain of catalytic residue at G398 (P = 0.0064);.;.;.;.;.;
MVP		0.97
MPC		0.74
ClinPred		1.0	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs864622557; hg19: chr5-125889986;