10-95606797-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_002860.4(ALDH18A1):c.2353G>A(p.Glu785Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,874 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALDH18A1 NM_002860.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.46

Genes affected

ALDH18A1 (HGNC:9722): (aldehyde dehydrogenase 18 family member A1) This gene is a member of the aldehyde dehydrogenase family and encodes a bifunctional ATP- and NADPH-dependent mitochondrial enzyme with both gamma-glutamyl kinase and gamma-glutamyl phosphate reductase activities. The encoded protein catalyzes the reduction of glutamate to delta1-pyrroline-5-carboxylate, a critical step in the de novo biosynthesis of proline, ornithine and arginine. Mutations in this gene lead to hyperammonemia, hypoornithinemia, hypocitrullinemia, hypoargininemia and hypoprolinemia and may be associated with neurodegeneration, cataracts and connective tissue diseases. Alternatively spliced transcript variants, encoding different isoforms, have been described for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in NM_002860.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.759

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALDH18A1	NM_002860.4	c.2353G>A	p.Glu785Lys	missense_variant	18/18	ENST00000371224.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALDH18A1	ENST00000371224.7	c.2353G>A	p.Glu785Lys	missense_variant	18/18	1	NM_002860.4	P3
ALDH18A1	ENST00000371221.3	c.2347G>A	p.Glu783Lys	missense_variant	18/18	1		A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251302 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135804

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461874 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

de Barsy syndrome;C1832669:Autosomal dominant spastic paraplegia type 9;C4225268:Cutis laxa, autosomal dominant 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 14, 2022

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. 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 tolerated. This variant has not been reported in the literature in individuals affected with ALDH18A1-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.0009%). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 785 of the ALDH18A1 protein (p.Glu785Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.010
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Benign	0.30	T;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Benign	0.067	D
MetaRNN	Pathogenic	0.76	D;D
MetaSVM	Benign	-0.46	T
MutationAssessor	Benign	1.2	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-1.9	N;N
REVEL	Uncertain	0.55
Sift	Benign	0.73	T;T
Sift4G	Benign	1.0	T;T
Polyphen		0.88	P;P
Vest4		0.78
MutPred		0.39		Gain of ubiquitination at E785 (P = 0.0247);.;
MVP		0.53
MPC		0.38
ClinPred		0.82	D
GERP RS		5.3
Varity_R		0.45
gMVP		0.87

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: rs1364987786; hg19: chr10-97366554;