intestinal neuroendocrine tumor G1

Summary

intestinal neuroendocrine tumor G1 (MONDO:0021533) is a cancer with 1 cohort gene.

At a glance

• Classification: Cancer
• Cohort genes: 1
• ClinVar variants: 1

Clinical features

No curated clinical features (Orphanet) for this disease.

Identifiers

Disease identifiers

Field	Value
Canonical name	intestinal neuroendocrine tumor G1
Mondo ID	MONDO:0021533
MeSH	C562842
OMIM	114900
NCIT	C4637
SNOMED CT	276816003
UMLS	C0349535
MedGen	138099
GARD	0025331
Anatomy (UBERON)	UBERON:0000160
Is cancer (heuristic)	yes

Also known as: carcinoid tumor of intestine · carcinoid tumor of the intestine · carcinoid tumour of intestine · carcinoid tumour of the intestine · grade 1 neuroendocrine neoplasm of intestine · intestinal carcinoid tumor · intestinal carcinoid tumour · intestinal NET G1 · intestinal neuroendocrine tumor G1 · intestine carcinoid tumor · intestine carcinoid tumor (disease) · intestine carcinoid tumour · intestine carcinoid tumour (disease) · intestine NET G1 · intestine neuroendocrine neoplasm G1 · intestine neuroendocrine tumor, well differentiated, low grade

Data availability: 1 ClinVar variant.

Disease family

An umbrella term covering 2 Mondo subtypes.

Classification path: disease › human disease › disease by body system or component › digestive system disorder › digestive system neuroendocrine neoplasm › digestive system neuroendocrine tumor, grade 1/2 › intestinal neuroendocrine tumor G1

Related subtypes (9): small intestine neuroendocrine tumor, well differentiated, low or intermediate grade, gastrin-producing neuroendocrine tumor, esophageal neuroendocrine tumor, L-cell glucagon-like peptide-producing neuroendocrine tumor, gastric neuroendocrine tumor, well differentiated, low or intermediate grade, neuroendocrine tumor of the colon, well differentiated, low or intermediate grade tumor, rectal neuroendocrine tumor, gallbladder neuroendocrine tumor, grade 1/2, pancreatic neuroendocrine tumor

Subtypes (2): small intestinal neuroendocrine tumor G1, colorectal neuroendocrine tumor G1

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

ClinVar germline variants

1 retrieved; paginated sample, class counts are floors:

1 benign/likely benign

ClinVar	Variant (HGVS)	Gene	Classification	Review
6909	NM_003002.4(SDHD):c.149A>G (p.His50Arg)	SDHD	Benign/Likely benign	criteria provided, multiple submitters, no conflicts

Genes & proteins

Mendelian disease overlap and somatic drivers

GenCC: 0 · Orphanet: 6 · OMIM-shared: 0 · Dual-evidence (GWAS+Mendelian): 0

Orphanet rare-disease linkage (cohort genes)

Gene	Orphanet ID	Rare disease
SDHD	Orphanet:100093	Carcinoid syndrome
SDHD	Orphanet:201	Cowden syndrome
SDHD	Orphanet:276621	Sporadic pheochromocytoma/secreting paraganglioma
SDHD	Orphanet:29072	Hereditary pheochromocytoma-paraganglioma
SDHD	Orphanet:3208	Isolated succinate-CoQ reductase deficiency
SDHD	Orphanet:97286	Carney-Stratakis syndrome

Cohort genes → proteins

1 cohort genes, 1 distinct canonical proteins.

Evidence partition

Subset	Genes
multi_evidence	1

Cohort genes (full)

Symbol	HGNC	Ensembl	UniProt	Name	Evidence
SDHD	HGNC:10683	ENSG00000204370	O14521	Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial	clinvar

Cohort function summary

Lead sentence per gene, UniProt-curated.

Symbol	Protein name	Function (lead sentence)
SDHD	Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial	Membrane-anchoring subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q).

Protein-family classification

Druggable: 0 · Difficult: 0 · Unknown: 1 · Druggable fraction: 0.0

Family distribution

Cohort families vs a genome-wide background (hypergeometric, BH-FDR; fold = observed/expected). Counts kept; sorted by enrichment, so the catch-all Other/Unknown bucket no longer leads.

Family	Genes	Fold	FDR
Other/Unknown	1	1.8×	0.558

Per-gene assignment

Symbol	Family	Druggable?	EC	InterPro (top 3)
SDHD	Other/Unknown	no		CybS, SQR/QFR_C/D

Expression context

Cohort genes with no expression data: 0.

1 cohort gene are a single-cell marker in ≥1 SCXA experiment.

Breadth distribution (Bgee present_calls)

Bucket	Genes
narrow (1-5 tissues)	0
moderate (6-20)	0
broad (>20)	1
unknown	0

Top tissues across cohort

Tissue	Cohort genes
jejunal mucosa	1
jejunum	1
rectum	1

Per-gene tissue summary (top 30)

Symbol	Bgee breadth	FANTOM5 breadth	SCXA	Top tissues
SDHD	287	ubiquitous	marker	jejunal mucosa, rectum, jejunum

Protein interactions among cohort

Intra-cohort edges: 0.

Hub genes (top 10 by interactor count)

Symbol	Interactor count
SDHD	2,229

Structural data

PDB: 1 · AlphaFold-only: 0 · No structure: 0

Cohort genes with PDB structures (top 30)

Symbol	UniProt	PDB entries
SDHD	O14521	2

Function

Pathway analysis

Distinct Reactome pathways touched by cohort: 3. Enrichment computed across 1 evidence-associated genes (1 with Reactome annotation).

Pathways by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

Pathway	Cohort genes	Fold	FDR	Sample cohort genes
Maturation of TCA enzymes and regulation of TCA cycle	1	571.0×	0.004	SDHD
Citric acid cycle (TCA cycle)	1	423.0×	0.004	SDHD
Respiratory electron transport	1	95.2×	0.011	SDHD

GO biological processes by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

GO term	Cohort genes	Fold	FDR	Sample cohort genes
regulation of catecholamine secretion	1	16852.0×	3e-04	SDHD
mitochondrial electron transport, succinate to ubiquinone	1	3370.4×	7e-04	SDHD
tricarboxylic acid cycle	1	510.7×	0.003	SDHD
proton motive force-driven mitochondrial ATP synthesis	1	263.3×	0.005	SDHD
cellular response to hypoxia	1	121.2×	0.008	SDHD

Therapeutics

Drug target analysis

Approved (phase 4): 0 · Phase ≥3: 0 · Phased (≥1): 0 · Undrugged: 1

Druggability breadth: 0 of 1 evidence-associated genes (0%) have a ChEMBL target (buckets above are over the deeply-mined display cohort).

Top cohort targets by molecule count

Symbol	Molecules	Max phase
SDHD	0	0

Bioactivity and enzyme data

Enzyme cohort genes (≥1 EC): 0.

Pharmacogenomics

Cohort genes with a PharmGKB record: 1; with CPIC/DPWG dosing guidelines: 0.

No cohort gene has a CPIC/DPWG genotype-guided dosing guideline (PharmGKB).

Drug repurposing candidates

0 approved/phased drugs hit cohort targets but don’t yet appear in disease-level clinical trials. Target-inhibition rationale is strongest for cancer driver genes; a bioactivity hit is a screening signal, not a treatment claim.

Druggability pyramid

Cohort genes binned by druggability tier (high → low):

Tier	Definition	Genes	Symbols
A	Approved (phase 4 drug)	0
B	Phased (≥1) drug, not yet approved	0
C	Druggable family + PDB, no drug	0
D	Druggable family + AlphaFold only, no drug	0
E	Difficult family or no structure, no drug	1	SDHD

Undrugged target profiles

1 cohort genes are undrugged. Ranked by ‘starting-point quality’ (assay depth + drugged-partner adjacency).

Symbol	ChEMBL assays	Drugged partners (top 3)
SDHD	0	—

Clinical trials & evidence

Clinical trials

Clinical trials: 0.