6-24495001-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001080.3(ALDH5A1):c.5C>T(p.Ala2Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000986 in 1,318,440 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000094 (0 hom.)
• Consequence: ALDH5A1 NM_001080.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.65

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]

GPLD1 (HGNC:4459): (glycosylphosphatidylinositol specific phospholipase D1) Many proteins are tethered to the extracellular face of eukaryotic plasma membranes by a glycosylphosphatidylinositol (GPI) anchor. The GPI-anchor is a glycolipid found on many blood cells. The protein encoded by this gene is a GPI degrading enzyme. Glycosylphosphatidylinositol specific phospholipase D1 hydrolyzes the inositol phosphate linkage in proteins anchored by phosphatidylinositol glycans, thereby releasing the attached protein from the plasma membrane. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALDH5A1	NM_001080.3	c.5C>T	p.Ala2Val	missense_variant	1/10	ENST00000357578.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALDH5A1	ENST00000357578.8	c.5C>T	p.Ala2Val	missense_variant	1/10	1	NM_001080.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151942 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000943 AC: 11 AN: 1166498 Hom.: 0 Cov.: 31 AF XY: 0.00000355 AC XY: 2 AN XY: 562770

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000330

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000103

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151942 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74234

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000378

ExAC AF: 0.00000889 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Succinate-semialdehyde dehydrogenase deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 24, 2022

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 2 of the ALDH5A1 protein (p.Ala2Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with ALDH5A1-related conditions. 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) performed at Invitae indicates that this missense variant is not expected to disrupt ALDH5A1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Uncertain	0.063	T
BayesDel_noAF	Benign	-0.15
Cadd	Uncertain	23
Dann	Uncertain	1.0
DEOGEN2	Benign	0.097	T;T;.
Eigen	Benign	-0.039
Eigen_PC	Benign	0.033
FATHMM_MKL	Benign	0.54	D
LIST_S2	Benign	0.50	T;T;T
M_CAP	Pathogenic	0.85	D
MetaRNN	Uncertain	0.56	D;D;D
MetaSVM	Benign	-0.64	T
MutationTaster	Benign	1.0	D;N;N;N
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-0.34	N;N;N
REVEL	Uncertain	0.46
Sift	Uncertain	0.0070	D;D;D
Sift4G	Uncertain	0.016	D;D;D
Polyphen		0.89	P;.;.
Vest4		0.38
MutPred		0.44		Loss of disorder (P = 0.0294);Loss of disorder (P = 0.0294);Loss of disorder (P = 0.0294);
MVP		0.83
MPC		0.37
ClinPred		0.60	D
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.19
gMVP		0.58

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: rs780751641; hg19: chr6-24495229;