AGPS

protein-coding

alkylglycerone phosphate synthase

Gene summary

This gene is a member of the FAD-binding oxidoreductase/transferase type 4 family. It encodes a protein that catalyzes the second step of ether lipid biosynthesis in which acyl-dihydroxyacetonephosphate (DHAP) is converted to alkyl-DHAP by the addition of a long chain alcohol and the removal of a long-chain acid anion. The protein is localized to the inner aspect of the peroxisomal membrane and requires FAD as a cofactor. Mutations in this gene have been associated with rhizomelic chondrodysplasia punctata, type 3 and Zellweger syndrome. [provided by RefSeq, Jul 2008]

MANE transcript

NM_003659.4

Inheritance

AR

ClinVar variants

P:29U:134B:278

Top phenotype

Rhizomelic chondrodysplasia punctata, type 3

gnomAD constraint

pLI —, LoF o/e 0.02

Max pathogenic AF

—

Genomic locus

chr2:177,392,746-177,567,024

External References & Databases

Transcript & Mutation Effects

hg38 • Region Span ~174.3 kb
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GenCC Phenotypes & Disease Associations

Curated gene-disease validity assertions and inheritance patterns

rhizomelic chondrodysplasia punctata type 3STRONG

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: PanelApp Australia

rhizomelic chondrodysplasia punctata type 3DEFINITIVE

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: Natera

rhizomelic chondrodysplasia punctata type 3STRONG

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: Labcorp Genetics (formerly Invitae)

rhizomelic chondrodysplasia punctata type 3MODERATE

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: Ambry Genetics

rhizomelic chondrodysplasia punctata type 3DEFINITIVE

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: Laboratory for Molecular Medicine

This gene-disease relationship has undergone rapid assessment. Classifications are based on preliminary review of gene-disease validity during analysis of genomic sequencing results.

alkylglycerone-phosphate synthase deficiencyDEFINITIVE

Inheritance Pattern: AR

Disease ID:MONDO:0100274

Submitter: ClinGen

The relationship between *AGPS* and alkylglycerone-phosphate synthase deficiency (rhizomelic chondrodysplasia punctata 3 [RCDP3] included), an autosomal recessive peroxisomal disorder, was evaluated using the ClinGen Clinical Validity Framework as of September 20, 2019 and updated by April 2022. *AGPS* encodes alkylglycerone-phosphate synthase (also known as alkyldihroxyacetonephosphate synthase, ADHAPS, alkyl-DHAP synthase), a peroxisomal enzyme catalyzing the second (last) step of plasmalogen synthesis. Deficiency of plasmalogens is a feature of RCDP. Variants in *AGPS* causing AGPS deficiency were first reported in 1998 (de Vet et al, PMID 9553082). Data from 8 patients with 9 unique variants (all missense except for one frameshift and one nonsense resulting from deletions) from six publications were curated (de Vet et al, 1998, PMID 9553082; de Vet et al, 1999, PMID 10553003; Thai et al, 2001, PMID 11152660; Itzkovitz et al, 2012, PMID 21990100; Noguchi et al, 2014, PMID 24849933, Shawi et al, 2021, PMID: 35070570). A total of 7.5 points were awarded for genetic evidence (note that this includes 2 points for a case for which the causative variant is unknown, and therefore the case could not be included in the summary matrix, but which appeared to be homozygous for a 128bp deletion in *AGPS* cDNA; PMID 10553003). The relationship between *AGPS* and AGPS deficiency is supported by experimental evidence including the biochemical function of AGPS which is consistent with the low levels of plasmalogens observed in individuals with AGPS deficiency (Brown et al, 1982, PMID 7096336; Nagan et al, 1997, PMID 9114014); the physical interaction of alkylglycerone-phosphate synthase with glyceronephosphate O-acyltransferase (encoded by GNPAT) which catalyzes the first step of plasmalogen synthesis (Biermann et al, 1999, PMID 102158610); the finding that the activity and level glyceronephosphate O-acyltransferase is dependent on the physical presence of alkylglycerone-phosphate synthase (de Vet et al, 1999, PMID 10553003; Itzkovitz et al, PMID 21990100); the knowledge that other genes with a role in plasmalogen synthesis (GNPAT, and PEX7 which encodes the PTS2 receptor necessary for important of AGPS into the peroxisomes) are implicated in causing RCDP (Hajra et al, 1995, PMID 8685243; Braverman et al, 1997, PMID 9090381; Braverman et al, 2012, PMID 20301447); the finding of reduced levels of *AGPS* cDNA and protein in patients with AGPS deficiency (Noguchi et al, 2014, PMID 24849933); and the features of a natural and two knock-out mouse models (Liegel et al, 2011, PMID 21353609; Liegel et al, 2014, PMID 25197626). More evidence may be available but the maximum points for experimental evidence (6 points) have been reached. In summary, *AGPS* is definitively associated with autosomal recessive AGPS deficiency. This has been repeatedly demonstrated in both the research and clinical diagnostic settings, and has been upheld over time.

rhizomelic chondrodysplasia punctata type 3DEFINITIVE

Inheritance Pattern: AR

Disease ID:MONDO:0010823

Submitter: G2P

Clinical Genomic Database (CGD)

Rhizomelic chondrodysplasia punctata, type 3AR

Manifestation: Biochemical; Musculoskeletal; Neurologic

Intervention: General

Rationale: Genetic knowledge may be beneficial related to issues such as selection of optimal supportive care, informed medical decision-making, prognostic considerations, and avoidance of unnecessary testing

Refs: 7807941; 9553082; 21990100Source: CGD (NHGRI)

ClinVar Associated Diseases & Phenotypes

Reported disease conditions connected to AGPS variants in ClinVar

6 Conditions Cataloged
not providedTotal: 556
Rhizomelic chondrodysplasia punctata type 3Total: 105
Inborn genetic diseasesTotal: 56
not specifiedTotal: 39
Rhizomelic chondrodysplasia punctataTotal: 24
AGPS-related disorderTotal: 13

ClinVar Variants & Pathogenicity by Type

Statistics based on transcript NM_003659.4. Only rare variants are included.

We include only reliable ClinVar variants with their consequences to MANE Select, MANE Plus Clinical transcripts, or transcripts with TSL equal to 1. Click a count to filter the variants table below.

Slight differences between displayed counts and ClinVar may occur due to a different transcript/consequence chosen by our variant effect predictor, or because we classify Benign/Likely benign as Likely benign and Pathogenic/Likely pathogenic as Likely pathogenic.

EffectPLPVUSLBBSum
synonymous
8
clinvar
267
clinvar
4
clinvar
279
missense
1
clinvar
3
clinvar
118
clinvar
7
clinvar
129
nonsense
1
clinvar
5
clinvar
1
clinvar
7
start loss
0
frameshift
3
clinvar
8
clinvar
1
clinvar
12
splice donor/acceptor (+/-2bp)
1
clinvar
7
clinvar
6
clinvar
14
Total6231342744441

Highest pathogenic variant AF is 0.000006583452

Loading ClinVar variants...

Transcript Catalog

Annotated transcript isoforms across RefSeq and Ensembl databases

Showing 4 of 46 transcripts
Transcript IDSourceProtein IDCoding ExonsMANE Status
NM_003659.4RefSeqNP_003650.120MANE Select
ENST00000264167.11EnsemblENSP00000264167.420MANE Select
ENST00000409888.1EnsemblENSP00000386688.15Standard
ENST00000409888.2EnsemblENSP00000386688.15Standard

Gene Ontology (GO) Annotations & Pathways

Biological processes, molecular functions, cellular components and pathways

Pathways ConsensusPathDB

  • Ether lipid metabolism - Homo sapiens (human)
  • Peroxisome - Homo sapiens (human)
  • Plasmalogen Synthesis
  • Triacylglyceride Synthesis
  • Metabolism of lipids

Biological Process

  • protein targeting to peroxisome
  • lipid biosynthetic process
  • ether lipid biosynthetic process
  • oxidation-reduction process

Molecular Function

  • protein binding
  • alkylglycerone-phosphate synthase activity
  • oxidoreductase activity
  • FAD binding

Cellular Component

  • nucleolus
  • mitochondrion
  • peroxisome
  • peroxisomal membrane
  • peroxisomal matrix

gnomAD Constraint

Source: gnomAD

Gene type
protein_coding
Transcript type
protein_coding
Transcript
ENST00000264167
Coding exons
20
Length
151193
Individuals with no LoFs
125723
Homozygous LoFs
0
Heterozygous LoFs
5
Defined
125728
p
0.0000199
Z-ScoreObservedExpectedObserved/ExpectedMutation RateTotal Possible
Missense3.231863580.5200.00001724284
Missense (PolyPhen)19104.830.181251194
Synonymous0.1491241260.9830.000006141245
Loss of Function5.75140.50.02470.00000200487

Population LoF Frequency

PopulationCAFp-valueStatus
African00.0absent
Latino/Admixed American00.0absent
Ashkenazi Jewish0.0000990.000099rare
East Asian00.0absent
Finnish00.0absent
European (Non-Finnish)0.0000260.000026rare
South Asian0.0000330.000033rare
Other00.0absent

dbNSFP Gene Annotations

Source: dbNSFP

Function
FUNCTION: Catalyzes the exchange of an acyl for a long-chain alkyl group and the formation of the ether bond in the biosynthesis of ether phospholipids. {ECO:0000250}.;
Disease
DISEASE: Rhizomelic chondrodysplasia punctata 3 (RCDP3) [MIM:600121]: A form of rhizomelic chondrodysplasia punctata, a disease characterized by severely disturbed endochondral bone formation, rhizomelic shortening of femur and humerus, vertebral disorders, dwarfism, cataract, cutaneous lesions, facial dysmorphism, and severe mental retardation with spasticity. {ECO:0000269|PubMed:11152660, ECO:0000269|PubMed:21990100, ECO:0000269|PubMed:9553082}. Note=The disease is caused by mutations affecting the gene represented in this entry.;

Recessive Scores

pRec
0.197

Intolerance Scores

LoFtool
0.124
RVIS EVS
-0.38
RVIS percentile EVS
27.42

Essentials

Essential (CRISPR)
E
Essential (CRISPR2)
N
Essential (gene trap)
N
Indispensability pred.
E
Indispensability score
0.998

Gene Damage Prediction

AllRecessiveDominant
MendelianMediumMediumMedium
Primary ImmunodeficiencyMediumMediumMedium
CancerMediumMediumMedium
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