U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

SI sucrase-isomaltase [ Homo sapiens (human) ]

Gene ID: 6476, updated on 31-Mar-2024

Summary

Go to the top of the page Help
Official Symbol
SIprovided by HGNC
Official Full Name
sucrase-isomaltaseprovided by HGNC
Primary source
HGNC:HGNC:10856
See related
Ensembl:ENSG00000090402 MIM:609845; AllianceGenome:HGNC:10856
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Homo sapiens
Lineage
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Summary
This gene encodes a sucrase-isomaltase enzyme that is expressed in the intestinal brush border. The encoded protein is synthesized as a precursor protein that is cleaved by pancreatic proteases into two enzymatic subunits sucrase and isomaltase. These two subunits heterodimerize to form the sucrose-isomaltase complex. This complex is essential for the digestion of dietary carbohydrates including starch, sucrose and isomaltose. Mutations in this gene are the cause of congenital sucrase-isomaltase deficiency.[provided by RefSeq, Apr 2010]
Expression
Biased expression in duodenum (RPKM 299.9), small intestine (RPKM 254.2) and 1 other tissue See more
Orthologs
mouse all
NEW
Try the new Gene table
Try the new Transcript table

Genomic context

Go to the top of the page Help
Location:
3q26.1
Exon count:
51
Annotation release Status Assembly Chr Location
RS_2023_10 current GRCh38.p14 (GCF_000001405.40) 3 NC_000003.12 (164978898..165157921, complement)
RS_2023_10 current T2T-CHM13v2.0 (GCF_009914755.1) 3 NC_060927.1 (167761814..167940822, complement)
105.20220307 previous assembly GRCh37.p13 (GCF_000001405.25) 3 NC_000003.11 (164696686..164796284, complement)

Chromosome 3 - NC_000003.12Genomic Context describing neighboring genes Neighboring gene NANOG hESC enhancer GRCh37_chr3:164448481-164448982 Neighboring gene long intergenic non-protein coding RNA 1324 Neighboring gene OCT4-NANOG hESC enhancer GRCh37_chr3:164582212-164582862 Neighboring gene H3K27ac hESC enhancer GRCh37_chr3:164607970-164608470 Neighboring gene uncharacterized LOC107986050 Neighboring gene uncharacterized LOC105374192 Neighboring gene long intergenic non-protein coding RNA 1322 Neighboring gene SLIT and NTRK like family member 3 Neighboring gene CDK7 strongly-dependent group 2 enhancer GRCh37_chr3:165177431-165178630

Genomic regions, transcripts, and products

Go to the top of the page Help

Go to nucleotide: Graphics FASTA GenBank

Expression

Go to the top of the page Help
  • Project title: HPA RNA-seq normal tissues
  • Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
  • BioProject: PRJEB4337
  • Publication: PMID 24309898
  • Analysis date: Wed Apr 4 07:08:55 2018

Bibliography

Go to the top of the pageHelp

Related articles in PubMed

  1. Prevalence of congenital sucrase-isomaltase deficiency in Turkey may be much higher than the estimates. Taskin DG, et al. J Genet, 2023. PMID 37349966
  2. The glucose-regulated protein GRP94 interacts avidly in the endoplasmic reticulum with sucrase-isomaltase isoforms that are associated with congenital sucrase-isomaltase deficiency. Hoter A, et al. Int J Biol Macromol, 2021 Sep 1. PMID 34242650
  3. Rare Hypomorphic Sucrase Isomaltase Variants in Relation to Irritable Bowel Syndrome Risk in UK Biobank. Zheng T, et al. Gastroenterology, 2021 Nov. PMID 34186061
  4. Increased Prevalence of Rare Sucrase-isomaltase Pathogenic Variants in Irritable Bowel Syndrome Patients. Garcia-Etxebarria K, et al. Clin Gastroenterol Hepatol, 2018 Oct. PMID 29408290, Free PMC Article
  5. Molecular pathogenicity of novel sucrase-isomaltase mutations found in congenital sucrase-isomaltase deficiency patients. Gericke B, et al. Biochim Biophys Acta Mol Basis Dis, 2017 Mar. PMID 28062276

See all (43) citations in PubMed

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
  1. Sucrase-isomaltase genotype and response to a starch-reduced and sucrose-reduced diet in IBS-D patients.
    Title: Sucrase-isomaltase genotype and response to a starch-reduced and sucrose-reduced diet in IBS-D patients.
  2. Prevalence of congenital sucrase-isomaltase deficiency in Turkey may be much higher than the estimates.
    Title: Prevalence of congenital sucrase-isomaltase deficiency in Turkey may be much higher than the estimates.
  3. Rare Hypomorphic Sucrase Isomaltase Variants in Relation to Irritable Bowel Syndrome Risk in UK Biobank.
    Title: Rare Hypomorphic Sucrase Isomaltase Variants in Relation to Irritable Bowel Syndrome Risk in UK Biobank.
  4. The glucose-regulated protein GRP94 interacts avidly in the endoplasmic reticulum with sucrase-isomaltase isoforms that are associated with congenital sucrase-isomaltase deficiency.
    Title: The glucose-regulated protein GRP94 interacts avidly in the endoplasmic reticulum with sucrase-isomaltase isoforms that are associated with congenital sucrase-isomaltase deficiency.
  5. Through a 2-step computational and experimental strategy, the present study found increased prevalence new dysfunctional SI variants associated with irritable bowel syndrome.
    Title: Increased Prevalence of Rare Sucrase-isomaltase Pathogenic Variants in Irritable Bowel Syndrome Patients.
  6. Three biosynthetic phenotypes for the novel SI mutations were identified. The first biosynthetic phenotype was defined by mutants that are intracellularly transported in a fashion similar to wild type SI and with normal, but varying, levels of enzymatic activity. The second biosynthetic phenotype was defined by mutants with delayed maturation and trafficking kinetics and reduced activity. The third is inactive.
    Title: Molecular pathogenicity of novel sucrase-isomaltase mutations found in congenital sucrase-isomaltase deficiency patients.
  7. Novel compound heterozygote V577G/C1531W SI mutations, which lead to lack of SI expression in the duodenal brush border, were found in a family with congenital sucrase-isomaltase deficiency.
    Title: Congenital Sucrase-isomaltase Deficiency: A Novel Compound Heterozygous Mutation Causing Aberrant Protein Localization.
  8. A common mutation was found in the sucrase-isomaltase gene, c.273_274delAG, to be responsible for the high prevalence of congenital sucrase-isomaltase deficiency among Inuit people.
    Title: Congenital sucrase-isomaltase deficiency: identification of a common Inuit founder mutation.
  9. SI mutations result in loss of enzyme function by preventing the biosynthesis of catalytically competent SI at the cell surface in lymphocytic leukemia
    Title: Functional analysis of sucrase-isomaltase mutations from chronic lymphocytic leukemia patients.
  10. study found four common mutations in the SI gene (3 of the 4 are in the sucrase domain, with 1 in the isomaltase domain) account for 59 percent of clinical symptoms of congenital sucrase-isomaltase deficiency (CSID); the remaining 41 percent were rare events
    Title: Four mutations in the SI gene are responsible for the majority of clinical symptoms of CSID.
Submit: New GeneRIF Correction See all GeneRIFs (19)

Phenotypes

Go to the top of the page Help

Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description Tests
Sucrase-isomaltase deficiency
MedGen: C1283620 OMIM: 222900 GeneReviews: Not available
Compare labs

Variation

Go to the top of the page Help

See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

Genotypes

Pathways from PubChem

Go to the top of the page

Interactions

Go to the top of the page Help
Products Interactant Other Gene Complex Source Pubs Description

General gene information

Go to the top of the page Help

Markers

Homology

Clone Names

  • MGC131621, MGC131622

Gene Ontology Provided by GOA

Function Evidence Code Pubs
enables alpha-1,4-glucosidase activity IBA
Inferred from Biological aspect of Ancestor
more info
  
enables carbohydrate binding IEA
Inferred from Electronic Annotation
more info
  
enables oligo-1,6-glucosidase activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables sucrose alpha-glucosidase activity TAS
Traceable Author Statement
more info
  
Process Evidence Code Pubs
involved_in polysaccharide digestion TAS
Traceable Author Statement
more info
  
involved_in sucrose catabolic process IDA
Inferred from Direct Assay
more info
 PubMed 
Component Evidence Code Pubs
located_in Golgi apparatus TAS
Traceable Author Statement
more info
 PubMed 
located_in apical plasma membrane IEA
Inferred from Electronic Annotation
more info
  
located_in brush border TAS
Traceable Author Statement
more info
 PubMed 
located_in extracellular exosome HDA PubMed 
located_in plasma membrane TAS
Traceable Author Statement
more info
  

General protein information

Go to the top of the page Help
Preferred Names
sucrase-isomaltase, intestinal
Names
Alpha-methylglucosidase
Oligo-1,6-glucosidase
alpha-glucosidase
oligosaccharide alpha-1,6-glucosidase
NP_001032.2
XP_011511380.1
XP_047304691.1
XP_047304692.1
XP_047304693.1
XP_054203545.1
XP_054203546.1
XP_054203547.1
XP_054203548.1

NCBI Reference Sequences (RefSeq)

Go to the top of the page Help

NEW Try the new Transcript table

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

Genomic

  1. NG_017043.1 RefSeqGene

    Range
    5000..104598
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. NM_001041.4 → NP_001032.2  sucrase-isomaltase, intestinal

    See identical proteins and their annotated locations for NP_001032.2

    Status: REVIEWED

    Source sequence(s)
    AC092695, AC140119, BC132860, BG187733, DA919374
    Consensus CDS
    CCDS3196.1
    UniProtKB/Swiss-Prot
    A2RUC3, P14410, Q1JQ80, Q1RMC2
    Related
    ENSP00000264382.3, ENST00000264382.8
    Conserved Domains (5) summary
    smart00018
    Location:70 → 112
    PD; P or trefoil or TFF domain
    cd06602
    Location:343 → 707
    GH31_MGAM_SI_GAA; maltase-glucoamylase, sucrase-isomaltase, lysosomal acid alpha-glucosidase
    cd14752
    Location:1100 → 1214
    GH31_N; N-terminal domain of glycosyl hydrolase family 31 (GH31)
    pfam01055
    Location:324 → 797
    Glyco_hydro_31; Glycosyl hydrolases family 31
    pfam16863
    Location:125 → 234
    NtCtMGAM_N; N-terminal barrel of NtMGAM and CtMGAM, maltase-glucoamylase

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2023_10

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCh38.p14 Primary Assembly

Genomic

  1. NC_000003.12 Reference GRCh38.p14 Primary Assembly

    Range
    164978898..165157921 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_047448737.1 → XP_047304693.1  sucrase-isomaltase, intestinal isoform X1

    UniProtKB/Swiss-Prot
    A2RUC3, P14410, Q1JQ80, Q1RMC2

  2. XM_047448735.1 → XP_047304691.1  sucrase-isomaltase, intestinal isoform X1

    UniProtKB/Swiss-Prot
    A2RUC3, P14410, Q1JQ80, Q1RMC2

  3. XM_047448736.1 → XP_047304692.1  sucrase-isomaltase, intestinal isoform X1

    UniProtKB/Swiss-Prot
    A2RUC3, P14410, Q1JQ80, Q1RMC2

  4. XM_011513078.3 → XP_011511380.1  sucrase-isomaltase, intestinal isoform X2

    Conserved Domains (5) summary
    smart00018
    Location:37 → 79
    PD; P or trefoil or TFF domain
    cd06602
    Location:310 → 674
    GH31_MGAM_SI_GAA; maltase-glucoamylase, sucrase-isomaltase, lysosomal acid alpha-glucosidase
    cd14752
    Location:1067 → 1181
    GH31_N; N-terminal domain of glycosyl hydrolase family 31 (GH31)
    pfam01055
    Location:291 → 764
    Glyco_hydro_31; Glycosyl hydrolases family 31
    pfam16863
    Location:92 → 201
    NtCtMGAM_N; N-terminal barrel of NtMGAM and CtMGAM, maltase-glucoamylase

Alternate T2T-CHM13v2.0

Genomic

  1. NC_060927.1 Alternate T2T-CHM13v2.0

    Range
    167761814..167940822 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_054347572.1 → XP_054203547.1  sucrase-isomaltase, intestinal isoform X1

  2. XM_054347570.1 → XP_054203545.1  sucrase-isomaltase, intestinal isoform X1

  3. XM_054347571.1 → XP_054203546.1  sucrase-isomaltase, intestinal isoform X1

  4. XM_054347573.1 → XP_054203548.1  sucrase-isomaltase, intestinal isoform X2

Nucleotide Protein
Heading Accession and Version
Protein Accession Links
GenPept Link UniProtKB Link
P14410.6 GenPept UniProtKB/Swiss-Prot:P14410

Gene LinkOut

The following LinkOut resources are supplied by external providers. These providers are responsible for maintaining the links.

Chemical Information
Medical
Molecular Biology Databases
Research Materials
Tools
Miscellaneous