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Aliases for SPG21 Gene

Aliases for SPG21 Gene

  • SPG21, Maspardin 2 3 5
  • Spastic Paraplegia 21 (Autosomal Recessive, Mast Syndrome) 2 3
  • Acid Cluster Protein 33 3 4
  • ACP33 3 4
  • Spastic Paraplegia 21 Autosomal Recessive Mast Syndrome Protein 4
  • Spastic Paraplegia 21 Protein 4
  • Maspardin 3
  • 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 (SPG21, Maspardin) is a Protein Coding gene. Diseases associated with SPG21 include Mast Syndrome and Paraplegia. Among its related pathways are Endocytosis. Gene Ontology (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

Additional gene information for SPG21 Gene

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

Genomics for SPG21 Gene

GeneHancer (GH) Regulatory Elements for SPG21 Gene

Promoters and enhancers for SPG21 Gene
GeneHancer (GH) Identifier GH Type GH
GH Sources Gene Association Score Total Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor
Binding Sites
Gene Targets
GH15J064988 Promoter/Enhancer 2.1 EPDnew Ensembl ENCODE 698.6 -0.1 -98 4.3 HDGF PKNOX1 CLOCK SMAD1 MLX ARNT ARID4B SIN3A DMAP1 IRF4 SPG21 CSNK1G1 ZNF609 INTS14 PARP16 SLC24A1 ENSG00000259635 MTFMT PDCD7 RBPMS2
GH15J064983 Enhancer 1.3 FANTOM5 Ensembl ENCODE 44.6 +5.2 5173 3 ELF3 MEIS2 PKNOX1 FOXA2 SAP130 MLX ARID4B ZSCAN9 RARA TEAD3 SPG21 RBPMS2 PLEKHO2 OAZ2 GC15M064944
GH15J065183 Promoter/Enhancer 2.1 EPDnew Ensembl ENCODE 14.2 -194.5 -194452 3 FOXA2 ARID4B SIN3A DMAP1 ZBTB7B YY1 POLR2B ZNF766 CBX5 ZNF207 PIR37257 GC15P069979 GC15P069978 GC15P069977 GC15P069976 GC15P069975 GC15P069974 GC15P069973 GC15P069972 CLPX
GH15J065066 Promoter/Enhancer 2 EPDnew Ensembl ENCODE dbSUPER 14.6 -79.3 -79308 6 PKNOX1 NR2F1 ZMYM3 NR2F2 FOSL1 ZFHX2 POLR2A GLIS1 ZKSCAN8 ZFP36 RASL12 UBAP1L SPG21 SLC51B RBPMS2 PIR51727
GH15J064840 Promoter/Enhancer 2.5 EPDnew FANTOM5 Ensembl ENCODE dbSUPER 10.5 +145.8 145849 7.7 HDGF PKNOX1 ARNT ARID4B SIN3A ZBTB7B ZNF143 SP3 SP5 REST PLEKHO2 ANKDD1A RBPMS2 SPG21 OAZ2 ZNF609 TRIP4 ENSG00000249240 GC15M064899
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data from 2017 publication | Request up-to-date GeneHancer data (full dataset)

GeneHancers around SPG21 on UCSC Golden Path with GeneCards custom track

Top Transcription factor binding sites by QIAGEN in the SPG21 gene promoter:
  • NF-kappaB1
  • NF-kappaB
  • Max1
  • c-Myc
  • AREB6

Genomic Locations for SPG21 Gene

Genomic Locations for SPG21 Gene
27,290 bases
Minus strand
27,287 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

Gene Families for SPG21 Gene

Human Protein Atlas (HPA):
  • Disease related genes
  • Predicted intracellular proteins

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

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.

Phenotypes From GWAS Catalog for SPG21 Gene

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

miRNA for SPG21 Gene

miRTarBase miRNAs that target SPG21

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for SPG21

Clone 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

Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for SPG21 gene
Compartment Confidence
cytosol 5
golgi apparatus 5
endosome 4
nucleus 3
mitochondrion 1

Subcellular locations from the

Human Protein Atlas (HPA)
  • Cytosol (3)
  • Vesicles (3)
See all subcellular structures

Gene Ontology (GO) - Cellular Components for SPG21 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005737 cytoplasm IEA --
GO:0005768 endosome IEA --
GO:0005794 Golgi apparatus IEA --
GO:0005829 cytosol IEA,IDA 11113139
GO:0010008 endosome membrane IEA --
genes like me logo Genes that share ontologies with SPG21: view

Pathways & Interactions for SPG21 Gene

SuperPathways for SPG21 Gene

SuperPathway 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:

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for SPG21

Clone 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 from GTEx, Illumina, BioGPS, and CGAP SAGE 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, 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).

Evidence on tissue expression from TISSUES for SPG21 Gene

  • Liver(4.4)
  • Bone marrow(4.3)
  • Eye(4.3)
  • Nervous system(4)
  • Lung(2.2)

Phenotype-based relationships between genes and organs from Gene ORGANizer for SPG21 Gene

Germ Layers:
  • ectoderm
  • mesoderm
  • nervous
  • skeletal muscle
Head and neck:
  • brain
  • head
  • foot
  • lower limb
  • peripheral nerve
  • peripheral nervous system
  • spinal cord
genes like me logo Genes that share expression patterns with SPG21: view

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
(Pan troglodytes)
Mammalia SPG21 34 33
  • 99.78 (n)
(Monodelphis domestica)
Mammalia SPG21 34
  • 97 (a)
(Ornithorhynchus anatinus)
Mammalia SPG21 34
  • 96 (a)
(Bos Taurus)
Mammalia SPG21 34 33
  • 93.4 (n)
(Canis familiaris)
Mammalia SPG21 34 33
  • 92.64 (n)
(Rattus norvegicus)
Mammalia Spg21 33
  • 89.36 (n)
(Mus musculus)
Mammalia Spg21 16 34 33
  • 88.06 (n)
(Gallus gallus)
Aves SPG21 34 33
  • 82.36 (n)
(Anolis carolinensis)
Reptilia SPG21 34
  • 90 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia spg21 33
  • 77.92 (n)
Str.18797 33
(Danio rerio)
Actinopterygii SPG21 (2 of 2) 34
  • 87 (a)
spg21 34 33
  • 75.65 (n)
Dr.27161 33
rainbow trout
(Oncorhynchus mykiss)
Actinopterygii Omy.627 33
thale cress
(Arabidopsis thaliana)
eudicotyledons AT4G12230 33
  • 53.38 (n)
(Oryza sativa)
Liliopsida Os10g0169800 33
  • 51.81 (n)
sea squirt
(Ciona savignyi)
Ascidiacea -- 34
  • 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)
Evolutionary constrained regions (ECRs) for SPG21: view image

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 Variation AA Info Type
rs11071822 benign, Spastic Paraplegia, Recessive 64,989,853(-) G/A 5_prime_UTR_variant, genic_upstream_transcript_variant, upstream_transcript_variant
rs115421171 uncertain-significance, Spastic Paraplegia, Recessive 64,965,473(-) C/A/T intron_variant
rs146986015 likely-benign, uncertain-significance, Mast syndrome, Spastic Paraplegia, Recessive, not specified 64,963,701(-) C/T coding_sequence_variant, synonymous_variant
rs147236778 benign, Mast syndrome, not specified 64,974,736(-) A/G coding_sequence_variant, synonymous_variant
rs147428832 benign, Mast syndrome, not specified 64,963,704(-) G/A coding_sequence_variant, synonymous_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)

Additional Variant Information for SPG21 Gene

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

SNP Genotyping and Copy Number Assay Products

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

Disorders for SPG21 Gene

MalaCards: The human disease database

(24) MalaCards diseases for SPG21 Gene - From: HGMD, OMIM, ClinVar, GTR, Orphanet, DISEASES, and GeneCards

Disorder Aliases PubMed IDs
mast syndrome
  • spastic paraplegia 21, autosomal recessive; spg21
  • paraplegia, lower
spastic paraplegia 11, autosomal recessive
  • spg11
spastic paraplegia 24, autosomal recessive
  • spg24
spastic paraplegia 32, autosomal recessive
  • spg32
- 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.

Additional Disease Information for SPG21

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 MA … Crosby AH (American journal of human genetics 2003) 2 3 4 22 58
  2. Cloning of ACP33 as a novel intracellular ligand of CD4. (PMID: 11113139) Zeitlmann L … Kolanus W (The Journal of biological chemistry 2001) 2 3 4 22 58
  3. Interaction of the SPG21 protein ACP33/maspardin with the aldehyde dehydrogenase ALDH16A1. (PMID: 19184135) Hanna MC … Blackstone C (Neurogenetics 2009) 3 4 22 58
  4. Complete sequencing and characterization of 21,243 full-length human cDNAs. (PMID: 14702039) Ota T … Sugano S (Nature genetics 2004) 3 4 58
  5. The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). (PMID: 15489334) Gerhard DS … MGC Project Team (Genome research 2004) 3 4 58

Products for SPG21 Gene

Sources for SPG21 Gene

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