NM_002860.4:c.1994G>A

Variant names:

• chr10-95611372-C-T
• rs766264810
• NM_002860.4:c.1994G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM5 PP3 PP5

The NM_002860.4(ALDH18A1):​c.1994G>A​(p.Arg665Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,614,060 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R665L) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: ALDH18A1 NM_002860.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.46
• Publications: 6 publications found

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]

ALDH18A1 Gene-Disease associations (from GenCC):

• cutis laxa, autosomal dominant 3

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• ALDH18A1-related de Barsy syndrome

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics
• autosomal recessive complex spastic paraplegia type 9B

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
• P5CS deficiency

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen, Illumina
• hereditary spastic paraplegia 9A

  Inheritance: AD, SD Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
• autosomal dominant complex spastic paraplegia type 9B

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal dominant cutis laxa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM5: Other missense variant is known to change same aminoacid residue: Variant chr10-95611372-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 217119.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.818
• PP5: Variant 10-95611372-C-T is Pathogenic according to our data. Variant chr10-95611372-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 3252995.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALDH18A1	NM_002860.4	c.1994G>A	p.Arg665Gln	missense_variant	Exon 16 of 18	ENST00000371224.7	NP_002851.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALDH18A1	ENST00000371224.7	c.1994G>A	p.Arg665Gln	missense_variant	Exon 16 of 18	1	NM_002860.4	ENSP00000360268.2
ALDH18A1	ENST00000371221.3	c.1988G>A	p.Arg663Gln	missense_variant	Exon 16 of 18	1		ENSP00000360265.3
ALDH18A1	ENST00000485428.1	n.610G>A		non_coding_transcript_exon_variant	Exon 4 of 4	2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152174 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251448 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461886 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727244

African (AFR) AF: 0.0000597 AC: 2 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112006

Other (OTH) AF: 0.0000497 AC: 3 AN: 60396

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152174 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74350

African (AFR) AF: 0.0000241 AC: 1 AN: 41444

American (AMR) AF: 0.00 AC: 0 AN: 15262

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Jan 01, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 665 of the ALDH18A1 protein (p.Arg665Gln). This variant is present in population databases (rs766264810, gnomAD 0.006%). This missense change has been observed in individual(s) with autosomal recessive hereditary spastic paraplegia (PMID: 29915212, 35464835). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 3252995). Invitae Evidence 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 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 currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not provided Uncertain:1

Apr 19, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 32798076, 35464835, 29915212) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.31	T;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.85	D;D
M_CAP	Benign	0.057	D
MetaRNN	Pathogenic	0.82	D;D
MetaSVM	Uncertain	-0.17	T
MutationAssessor	Uncertain	2.6	M;.
PhyloP100		7.5
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-1.4	N;N
REVEL	Uncertain	0.32
Sift	Benign	0.10	T;T
Sift4G	Benign	0.14	T;T
Polyphen		0.99	D;D
Vest4		0.85
MutPred		0.37		Gain of methylation at K662 (P = 0.0723);.;
MVP		0.78
MPC		0.87
ClinPred		0.83	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.27
gMVP		0.81
Mutation Taster		=31/69	disease causing

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

Other links and lift over

dbSNP: rs766264810; hg19: chr10-97371129; COSMIC: COSV64663711;