NCAPD3

Chr 11

non-SMC condensin II complex subunit D3

Also known as: CAP-D3, CAPD3, MCPH22, hCAP-D3, hHCP-6, hcp-6

NCBI Gene: 23310 ENSG00000151503 UniProt: P42695

NCAPD3 encodes a regulatory subunit of the condensin-2 complex that establishes mitotic chromosome architecture and is essential for chromosome condensation and decatenation during cell division, particularly in neuronal stem cells during early neurogenesis. Mutations cause primary microcephaly 22, an autosomal recessive disorder affecting brain development and cortex size. The gene is highly constrained against loss-of-function variants (LOEUF 0.489), reflecting its essential role in normal neurodevelopment.

ResearchSummary from RefSeq, OMIM, UniProt

Condensin complexes I and II play essential roles in mitotic chromosome assembly and segregation. Both condensins contain 2 invariant structural maintenance of chromosome (SMC) subunits, SMC2 (MIM 605576) and SMC4 (MIM 605575), but they contain different sets of non-SMC subunits. NCAPD3 is 1 of 3 non-SMC subunits that define condensin II (Ono et al., 2003 [PubMed 14532007]).[supplied by OMIM, Mar 2008]

ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtMicrocephaly 22, primary, autosomal recessive

Clinical highlights

Interpreting a novel variant

Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

0.49

LOEUF

LOF

Mechanism· G2P

Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429