rs375628463

Positions:

• chr6-24515243-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_001080.3(ALDH5A1):​c.803G>A​(p.Gly268Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000186 in 1,613,390 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 Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000086 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00020 (0 hom.)
• Consequence: ALDH5A1 NM_001080.3 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 8.81

Genes affected

ALDH5A1 (HGNC:408): (aldehyde dehydrogenase 5 family member A1) This protein belongs to the aldehyde dehydrogenase family of proteins. This gene encodes a mitochondrial NAD(+)-dependent succinic semialdehyde dehydrogenase. A deficiency of this enzyme, known as 4-hydroxybutyricaciduria, is a rare inborn error in the metabolism of the neurotransmitter 4-aminobutyric acid (GABA). In response to the defect, physiologic fluids from patients accumulate GHB, a compound with numerous neuromodulatory properties. Two transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.982
• PP5: Variant 6-24515243-G-A is Pathogenic according to our data. Variant chr6-24515243-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 235512.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-24515243-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALDH5A1	NM_001080.3	c.803G>A	p.Gly268Glu	missense_variant	5/10	ENST00000357578.8
ALDH5A1	NM_170740.1	c.842G>A	p.Gly281Glu	missense_variant	6/11
ALDH5A1	NM_001368954.1	c.727-5158G>A		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALDH5A1	ENST00000357578.8	c.803G>A	p.Gly268Glu	missense_variant	5/10	1	NM_001080.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000858 AC: 13 AN: 151558 Hom.: 0 Cov.: 31

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: 0.000191

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000875 AC: 22 AN: 251478 Hom.: 0 AF XY: 0.000110 AC XY: 15 AN XY: 135912

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000145

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: 0.000141

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000196 AC: 287 AN: 1461832 Hom.: 0 Cov.: 34 AF XY: 0.000187 AC XY: 136 AN XY: 727214

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000134

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000249

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000858 AC: 13 AN: 151558 Hom.: 0 Cov.: 31 AF XY: 0.0000270 AC XY: 2 AN XY: 73956

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: 0.000191

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000126 Hom.: 0

Bravo AF: 0.0000982

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000778 AC: 3

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.0000824 AC: 10

EpiCase AF: 0.000164

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Succinate-semialdehyde dehydrogenase deficiency Pathogenic:6

Pathogenic, criteria provided, single submitter	curation	Elsea Laboratory, Baylor College of Medicine	Mar 08, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 04, 2024	This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 268 of the ALDH5A1 protein (p.Gly268Glu). This variant is present in population databases (rs375628463, gnomAD 0.01%). This missense change has been observed in individual(s) with succinic semialdehyde dehydrogenase deficiency (PMID: 11243727, 14635103, 27104484). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 235512). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on ALDH5A1 protein function. Experimental studies have shown that this missense change affects ALDH5A1 function (PMID: 14635103). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Nov 01, 2018	The ALDH5A1 c.803G>A (p.Gly268Glu) missense variant, also known as the p.Gly281Glu variant, has been reported in a compound heterozygous state in five unrelated individuals with succinic semialdehyde dehydrogenase (SSADH) deficiency (Hogema et al. 2001; Akaboshi et al. 2003). The p.Gly268Glu variant was absent from 140 control chromosomes and is reported at a frequency of 0.000145 in the Latino population of the Genome Aggregation Database. HEK293 cells expressing the p.Gly268Glu variant demonstrated <1% SSADH activity compared to wild type (Akaboshi et al. 2003). Based on the evidence, the p.Gly268Glu variant is classified as pathogenic for succinic semialdehyde dehydrogenase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 27, 2023	Variant summary: ALDH5A1 c.803G>A (p.Gly268Glu) 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 8.7e-05 in 251478 control chromosomes (gnomAD). c.803G>A has been reported in the literature in individuals affected with Succinic Semialdehyde Dehydrogenase Deficiency (example: Akaboshi_2003). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (example: Akaboshi_ALDH5A1_HumMutat_2003). The following publications have been ascertained in the context of this evaluation (PMID: 11243727, 14635103). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 19, 2021	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genomics Laboratory, Stanford Medicine	Oct 28, 2020	The p.Gly268Glu variant in the ALDH5A1 gene has been previously reported in 7 unrelated individuals with succinic semialdehyde dehydrogenase deficiency (Akaboshi, et al., 2003, Hogema et al., 2001; Horvath et al., 2016). All affected individuals were compound heterozygotes. This variant was determined to be in trans with a disease-associated variant (p.Trp204*, p.Arg412*), consistent with autosomal recessive inheritance. The presence of this variant with a likely disease causing variant on the opposite allele increases suspicion for its pathogenicity. This variant has also been identified in 24/282406 chromosomes by the Genome Aggregation Database (http://gnomad.broadinstitute.org/). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. In vitro functional studies of the p.Gly268Glu variant suggest a deleterious effect to the protein that is sufficient to be disease-causing (Akaboshi et al., 2003; Hogema et al., 2001). Computational tools predict that the p.Gly268Glu variant is deleterious; however, the accuracy of in silico algorithms is limited. These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, there is sufficient evidence to classify the p.Gly268Glu variant as pathogenic for autosomal recessive succinic semialdehyde dehydrogenase deficiency based on the information above. [ACMG evidence codes used: PS4; PS3_Moderate; PM2; PM3; PP3] -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jun 29, 2023	Published functional studies demonstrate that G268E results in loss of SSADH enzymatic activity (Akaboshi et al., 2003; Pop et al., 2020); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 27104484, 25525159, 20174634, 19300440, 31515079, 31440721, 32402538, 23825041, 26964512, 20804942, 11243727, 14635103, 25558043, 33203024) -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics	Feb 09, 2015	- -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 28, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.40
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;D;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.74	D
MutationAssessor	Pathogenic	3.5	M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Pathogenic	-7.4	D;D;D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.97
MVP		0.98
MPC		1.1
ClinPred		0.98	D
GERP RS		5.3
Varity_R		0.99
gMVP		0.95

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: rs375628463; hg19: chr6-24515471;