rs757876226

Positions:

• chr10-95621105-C-G
• chr10-95621105-C-T

Variant summary

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

The NM_002860.4(ALDH18A1):​c.1393G>C​(p.Glu465Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E465K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ALDH18A1 NM_002860.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.39

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 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALDH18A1	NM_002860.4	c.1393G>C	p.Glu465Gln	missense_variant	12/18	ENST00000371224.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALDH18A1	ENST00000371224.7	c.1393G>C	p.Glu465Gln	missense_variant	12/18	1	NM_002860.4	P3
ALDH18A1	ENST00000371221.3	c.1387G>C	p.Glu463Gln	missense_variant	12/18	1		A1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461888 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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

Labcorp Genetics (formerly Invitae), Labcorp

Oct 22, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 465 of the ALDH18A1 protein (p.Glu465Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ALDH18A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 579657). 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 ALDH18A1 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	0.14
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T;.
Eigen	Uncertain	0.63
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Benign	0.024	T
MetaRNN	Uncertain	0.55	D;D
MetaSVM	Benign	-0.34	T
MutationAssessor	Benign	1.2	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Benign	-1.4	N;N
REVEL	Uncertain	0.31
Sift	Benign	0.13	T;T
Sift4G	Benign	0.29	T;T
Polyphen		0.98	D;D
Vest4		0.50
MutPred		0.28		Gain of MoRF binding (P = 0.0331);.;
MVP		0.58
MPC		0.40
ClinPred		0.78	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.51
gMVP		0.65

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: rs757876226; hg19: chr10-97380862;