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Aliases for SPG21 Gene

Aliases for SPG21 Gene

  • Spastic Paraplegia 21 (Autosomal Recessive, Mast Syndrome) 2 3 5
  • Acid Cluster Protein 33 3 4
  • Maspardin 2 3
  • ACP33 3 4
  • Spastic Paraplegia 21 Autosomal Recessive Mast Syndrome Protein 4
  • Spastic Paraplegia 21 Protein 4
  • BM-019 3
  • GL010 3
  • Mast 3

External Ids for SPG21 Gene

Previous GeneCards Identifiers for SPG21 Gene

  • GC13U900001
  • GC15M062972
  • GC15M063042
  • GC15M065255
  • GC15M042080

Summaries for SPG21 Gene

Entrez Gene Summary for SPG21 Gene

  • The protein encoded by this gene binds to the hydrophobic C-terminal amino acids of CD4 which are involved in repression of T cell activation. The interaction with CD4 is mediated by the noncatalytic alpha/beta hydrolase fold domain of this protein. It is thus proposed that this gene product modulates the stimulatory activity of CD4. Mutations in this gene are associated with autosomal recessive spastic paraplegia 21 (SPG21), also known as mast syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]

GeneCards Summary for SPG21 Gene

SPG21 (Spastic Paraplegia 21 (Autosomal Recessive, Mast Syndrome)) is a Protein Coding gene. Diseases associated with SPG21 include Mast Syndrome and Paraplegia. Among its related pathways are Endocytosis. GO annotations related to this gene include CD4 receptor binding.

UniProtKB/Swiss-Prot for SPG21 Gene

  • May play a role as a negative regulatory factor in CD4-dependent T-cell activation.

Gene Wiki entry for SPG21 Gene

No data available for Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for SPG21 Gene

Genomics for SPG21 Gene

Regulatory Elements for SPG21 Gene

Enhancers for SPG21 Gene
GeneHancer Identifier Enhancer Score Enhancer Sources Gene-Enhancer Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor Binding Sites within enhancer Gene Targets for Enhancer
- Elite enhancer/Elite enhancer-gene association

Enhancers around SPG21 on UCSC Golden Path with GeneCards custom track

Promoters for SPG21 Gene
Ensembl Regulatory Elements (ENSRs) TSS Distance (bp) Size (bp) Binding Sites for Transcription Factors within promoters

Genomic Location for SPG21 Gene

64,963,021 bp from pter
64,990,310 bp from pter
27,290 bases
Minus strand

Genomic View for SPG21 Gene

Genes around SPG21 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
SPG21 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for SPG21 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for SPG21 Gene

Proteins for SPG21 Gene

  • Protein details for SPG21 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Protein Accession:
    Secondary Accessions:
    • B4DW44
    • Q6ZMB6

    Protein attributes for SPG21 Gene

    308 amino acids
    Molecular mass:
    34960 Da
    Quaternary structure:
    • Interacts with CD4. Interacts with ALDH16A1.

    Alternative splice isoforms for SPG21 Gene


neXtProt entry for SPG21 Gene

Post-translational modifications for SPG21 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

No data available for DME Specific Peptides for SPG21 Gene

Domains & Families for SPG21 Gene

Protein Domains for SPG21 Gene

Suggested Antigen Peptide Sequences for SPG21 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the AB hydrolase superfamily.
  • Belongs to the AB hydrolase superfamily.
genes like me logo Genes that share domains with SPG21: view

No data available for Gene Families for SPG21 Gene

Function for SPG21 Gene

Molecular function for SPG21 Gene

UniProtKB/Swiss-Prot Function:
May play a role as a negative regulatory factor in CD4-dependent T-cell activation.

Gene Ontology (GO) - Molecular Function for SPG21 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005515 protein binding IPI 16189514
GO:0042609 CD4 receptor binding IPI 11113139
genes like me logo Genes that share ontologies with SPG21: view
genes like me logo Genes that share phenotypes with SPG21: view

Human Phenotype Ontology for SPG21 Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Model Products

CRISPR Products

miRNA for SPG21 Gene

miRTarBase miRNAs that target SPG21

Inhibitory RNA Products

Clone Products

Flow Cytometry Products

No data available for Enzyme Numbers (IUBMB) , Animal Models , Transcription Factor Targets and HOMER Transcription for SPG21 Gene

Localization for SPG21 Gene

Subcellular locations from UniProtKB/Swiss-Prot for SPG21 Gene

Cytoplasm, cytosol. Membrane; Peripheral membrane protein. Endosome membrane; Peripheral membrane protein. Golgi apparatus, trans-Golgi network membrane; Peripheral membrane protein. Note=Partially localized in the cytosol but also accumulated on an intracellular vesicular compartment. Colocalizes with CD4 on endosomal/trans-Golgi network.

Subcellular locations from

Jensen Localization Image for SPG21 Gene COMPARTMENTS Subcellular localization image for SPG21 gene
Compartment Confidence
cytosol 5
golgi apparatus 5
endosome 3
nucleus 3
mitochondrion 2
cytoskeleton 1

Gene Ontology (GO) - Cellular Components for SPG21 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005737 cytoplasm IDA --
GO:0005829 cytosol IDA 11113139
GO:0010008 endosome membrane IEA --
GO:0030140 trans-Golgi network transport vesicle IDA 11113139
GO:0043231 intracellular membrane-bounded organelle IDA --
genes like me logo Genes that share ontologies with SPG21: view

Pathways & Interactions for SPG21 Gene

SuperPathways for SPG21 Gene

Superpath Contained pathways
1 Endocytosis
genes like me logo Genes that share pathways with SPG21: view

Pathways by source for SPG21 Gene

1 KEGG pathway for SPG21 Gene

Gene Ontology (GO) - Biological Process for SPG21 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0050851 antigen receptor-mediated signaling pathway IC 11113139
genes like me logo Genes that share ontologies with SPG21: view

No data available for SIGNOR curated interactions for SPG21 Gene

Drugs & Compounds for SPG21 Gene

No Compound Related Data Available

Transcripts for SPG21 Gene

Unigene Clusters for SPG21 Gene

Spastic paraplegia 21 (autosomal recessive, Mast syndrome):
Representative Sequences:

CRISPR Products

Inhibitory RNA Products

Clone Products

Flow Cytometry Products

Alternative Splicing Database (ASD) splice patterns (SP) for SPG21 Gene

ExUns: 1a · 1b ^ 2a · 2b ^ 3a · 3b ^ 4 ^ 5 ^ 6 ^ 7a · 7b · 7c ^ 8 ^ 9a · 9b ^ 10 ^ 11 ^ 12 ^ 13
SP1: - - - - - - -
SP2: - - - - -
SP3: - - -
SP5: - - - - - - - -
SP6: - - - - -

Relevant External Links for SPG21 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for SPG21 Gene

mRNA expression in normal human tissues for SPG21 Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

Protein differential expression in normal tissues from HIPED for SPG21 Gene

This gene is overexpressed in Bone (18.3), Monocytes (7.5), and Peripheral blood mononuclear cells (6.7).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, PaxDb, MaxQB, and MOPED for SPG21 Gene

Protein tissue co-expression partners for SPG21 Gene

- Elite partner

NURSA nuclear receptor signaling pathways regulating expression of SPG21 Gene:


SOURCE GeneReport for Unigene cluster for SPG21 Gene:


mRNA Expression by UniProt/SwissProt for SPG21 Gene:

Tissue specificity: Expressed in all tissues tested, including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. Expressed in J.CaM1.6, HuT 78 and HeLa cell lines (at protein level).
genes like me logo Genes that share expression patterns with SPG21: view

Primer Products

No data available for mRNA differential expression in normal tissues for SPG21 Gene

Orthologs for SPG21 Gene

This gene was present in the common ancestor of eukaryotes.

Orthologs for SPG21 Gene

Organism Taxonomy Gene Similarity Type Details
(Bos Taurus)
Mammalia SPG21 34
  • 93.4 (n)
  • 98.7 (a)
SPG21 35
  • 99 (a)
(Canis familiaris)
Mammalia SPG21 34
  • 92.64 (n)
  • 98.7 (a)
SPG21 35
  • 99 (a)
(Mus musculus)
Mammalia Spg21 34
  • 88.06 (n)
  • 98.05 (a)
Spg21 16
Spg21 35
  • 98 (a)
(Pan troglodytes)
Mammalia SPG21 34
  • 99.78 (n)
  • 100 (a)
SPG21 35
  • 100 (a)
(Rattus norvegicus)
Mammalia Spg21 34
  • 89.36 (n)
  • 96.92 (a)
(Monodelphis domestica)
Mammalia SPG21 35
  • 97 (a)
(Ornithorhynchus anatinus)
Mammalia SPG21 35
  • 96 (a)
(Gallus gallus)
Aves SPG21 34
  • 82.36 (n)
  • 94.81 (a)
SPG21 35
  • 93 (a)
(Anolis carolinensis)
Reptilia SPG21 35
  • 90 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia spg21 34
  • 77.92 (n)
  • 89.61 (a)
Str.18797 34
(Danio rerio)
Actinopterygii Dr.27161 34
spg21 34
  • 75.65 (n)
  • 87.66 (a)
spg21 35
  • 87 (a)
SPG21 (2 of 2) 35
  • 87 (a)
rainbow trout
(Oncorhynchus mykiss)
Actinopterygii Omy.627 34
thale cress
(Arabidopsis thaliana)
eudicotyledons AT4G12230 34
  • 53.38 (n)
  • 45.86 (a)
(Oryza sativa)
Liliopsida Os10g0169800 34
  • 51.81 (n)
  • 44.96 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 35
  • 45 (a)
Species where no ortholog for SPG21 was found in the sources mined by GeneCards:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African clawed frog (Xenopus laevis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)

Evolution for SPG21 Gene

Gene Tree for SPG21 (if available)
Gene Tree for SPG21 (if available)

Paralogs for SPG21 Gene

No data available for Paralogs for SPG21 Gene

Variants for SPG21 Gene

Sequence variations from dbSNP and Humsavar for SPG21 Gene

SNP ID Clin Chr 15 pos Sequence Context AA Info Type
rs4128936 -- 64,985,367(-) TCGTT(C/T)AATCA intron-variant
rs4238398 -- 64,982,611(+) ACACT(C/T)CTGCA intron-variant
rs4316701 -- 64,981,257(+) CAAAG(A/G)GCTGC intron-variant
rs4346160 -- 64,972,413(+) AGCAA(C/T)AAAAA intron-variant
rs4365241 -- 64,975,419(+) gctac(C/T)tggga intron-variant

Structural Variations from Database of Genomic Variants (DGV) for SPG21 Gene

Variant ID Type Subtype PubMed ID
esv2763104 CNV gain 21179565
nsv480314 CNV novel sequence insertion 20440878
nsv510404 OTHER sequence alteration 20534489
nsv833041 CNV loss 17160897

Variation tolerance for SPG21 Gene

Residual Variation Intolerance Score: 18.7% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 0.64; 13.67% of all genes are more intolerant (likely to be disease-causing)

Relevant External Links for SPG21 Gene

Human Gene Mutation Database (HGMD)
SNPedia medical, phenotypic, and genealogical associations of SNPs for

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for SPG21 Gene

Disorders for SPG21 Gene

MalaCards: The human disease database

(3) MalaCards diseases for SPG21 Gene - From: OMIM, ClinVar, GeneTests, Orphanet, DISEASES, and GeneCards

Disorder Aliases PubMed IDs
mast syndrome
  • autosomal recessive spastic paraplegia 21
  • paraplegia, lower
hereditary spastic paraplegia
  • familial spastic paraplegia
- elite association - COSMIC cancer census association via MalaCards
Search SPG21 in MalaCards View complete list of genes associated with diseases


  • Spastic paraplegia 21, autosomal recessive (SPG21) [MIM:248900]: A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG21 is associated with dementia and other central nervous system abnormalities. Subtle childhood abnormalities may be present, but the main features develop in early adulthood. The disease is slowly progressive, and cerebellar and extrapyramidal signs are also found in patients with advanced disease. Patients have a thin corpus callosum and white-matter abnormalities. {ECO:0000269 PubMed:14564668}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Relevant External Links for SPG21

Atlas of Genetics and Cytogenetics in Oncology and Haematology:
genes like me logo Genes that share disorders with SPG21: view

No data available for Genatlas for SPG21 Gene

Publications for SPG21 Gene

  1. Maspardin is mutated in Mast syndrome, a complicated form of hereditary spastic paraplegia associated with dementia. (PMID: 14564668) Simpson M.A. … Crosby A.H. (Am. J. Hum. Genet. 2003) 2 3 4 22 65
  2. Cloning of ACP33 as a novel intracellular ligand of CD4. (PMID: 11113139) Zeitlmann L. … Kolanus W. (J. Biol. Chem. 2001) 2 3 4 22 65
  3. Interaction of the SPG21 protein ACP33/maspardin with the aldehyde dehydrogenase ALDH16A1. (PMID: 19184135) Hanna M.C. … Blackstone C. (Neurogenetics 2009) 3 4 22 65
  4. Complete sequencing and characterization of 21,243 full-length human cDNAs. (PMID: 14702039) Ota T. … Sugano S. (Nat. Genet. 2004) 3 4 65
  5. The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). (PMID: 15489334) Gerhard D.S. … Malek J. (Genome Res. 2004) 3 4 65

Products for SPG21 Gene

Sources for SPG21 Gene

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