| domain | key finding | ontology-ready terms/IDs where confidently known | evidence type | key source/date/DOI |
|---|---|---|---|---|
| Disease definition / core triad | Meier-Gorlin syndrome (MGORS), previously called ear-patella-short stature syndrome, is a rare microcephalic primordial dwarfism classically defined by short stature, microtia, and patella hypo/aplasia; many patients also have genital anomalies and post-pubertal female mammary hypoplasia | Candidate disease ontology term: MONDO not confirmed here; phenotype terms confidently usable: short stature HP:0004322; microtia HP:0008551; patellar aplasia/hypoplasia candidate HPO term(s), exact ID not confirmed here; primordial dwarfism candidate term not confirmed here | Human disease review / cohort synthesis | Nielsen-Dandoroff et al., 2023, Eur J Hum Genet, published Apr 2023, https://doi.org/10.1038/s41431-023-01359-z (pqac-00000001, pqac-00000009) |
| Inheritance | Usually autosomal recessive; most disease genes act through biallelic hypomorphic variants; GMNN is an exception reported with autosomal dominant inheritance in the literature summarized by the review evidence | Autosomal recessive; autosomal dominant (GMNN exception) | Human genetics review | Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z; McQuaid et al., 2022, https://doi.org/10.1172/jci.insight.155648 (pqac-00000001, pqac-00000010) |
| Causal gene set | 13 genes associated with MGORS/relevant MGORS spectrum: ORC1, ORC4, ORC6, CDT1, CDC6, GMNN, CDC45, DONSON, MCM3, MCM5, MCM7, GINS2, GINS3 | HGNC gene symbols listed; pre-RC / CMG-associated genes | Human review integrating primary studies | Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z (pqac-00000001, pqac-00000011, pqac-00000017) |
| Molecular mechanism | Core mechanism is defective DNA replication initiation/licensing and/or CMG helicase assembly, reducing loading of early replication machinery onto replication origins and impairing cellular proliferation during development | GO candidate terms: DNA replication initiation; DNA replication; replication origin licensing; CMG helicase complex assembly (exact GO IDs not confirmed here) | Human review + functional studies | Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z; Kingsley et al., 2023, https://doi.org/10.1093/nar/gkad694; Evrin et al., 2023, https://doi.org/10.15252/embr.202357677 (pqac-00000009, pqac-00000018) |
| Representative variant: GINS2 | Homozygous GINS2 NM_016095.2:c.341G>T, p.(Arg114Leu) causes MGORS with craniosynostosis; missense change affects a conserved residue at the CDC45/MCM5 docking site, likely disrupting CMG function | GINS2; missense variant; craniosynostosis phenotype term candidate, exact HPO ID not confirmed here | Human case + yeast functional modeling | Sá et al., 2022, J Med Genet, published Aug 2022, https://doi.org/10.1136/jmedgenet-2020-107572 (pqac-00000007, pqac-00000008) |
| Representative variant: GINS3 | Hypomorphic GINS3 variants affecting Asp24 cause an MGORS-like phenotype in 7 individuals from 5 families; effects include impaired proliferation, S-phase accumulation, reduced protein half-life, altered replisome interactions, and slower fork progression | GINS3; hypomorphic missense spectrum affecting Asp24 | Human genetics + in vitro + yeast + mouse | McQuaid et al., 2022, JCI Insight, published May 2022, https://doi.org/10.1172/jci.insight.155648 (pqac-00000005) |
| Representative variant: CDT1 | Novel homozygous intronic CDT1 variant c.352-30A>C disrupts a branch point, causes exon 3 skipping on minigene assay, and expands the mutational spectrum to noncanonical splice/branch-point defects | CDT1; intronic/splicing variant; likely pathogenic by ACMG in study | Human case + minigene functional assay | Li et al., 2024, Orphanet J Rare Dis, published Dec 2024, https://doi.org/10.1186/s13023-024-03430-4 (pqac-00000012) |
| DONSON | DONSON is now established within the MGORS spectrum; 2023 studies show it is required for Cdc45 and GINS chromatin association and for CMG helicase assembly during S phase, explaining how DONSON variants cause disease | DONSON; CMG helicase assembly; replication initiation | Human review + Xenopus extract + mammalian cell studies | Kingsley et al., 2023, https://doi.org/10.1093/nar/gkad694; Evrin et al., 2023, https://doi.org/10.15252/embr.202357677; Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z (pqac-00000013, pqac-00000018, pqac-00000016) |
| Growth / phenotype statistics | Fewer than 100 cases were noted in the 2023 review; severe prenatal/postnatal growth failure is typical. In the 2024 review of molecularly defined cases, mean birth length was -3.9 SDS, birth weight -3.4 SDS, and adult height averaged -4.5 SDS; reported mean adult heights were 137.7 cm in females and 147.0 cm in males | short stature HP:0004322; intrauterine growth restriction candidate term not confirmed here; microcephaly candidate term not confirmed here | Human review / literature summary | Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z; Li et al., 2024, https://doi.org/10.1186/s13023-024-03430-4 (pqac-00000001, pqac-00000000) |
| Diagnostic phenotype threshold | At least two of the three core features are present in 97% of patients summarized in the GINS3 paper’s background review, supporting phenotype-driven suspicion even when the full triad is incomplete | short stature HP:0004322; microtia HP:0008551; patella aplasia/hypoplasia candidate HPO term(s) | Human literature synthesis | McQuaid et al., 2022, https://doi.org/10.1172/jci.insight.155648 (pqac-00000003) |
| Growth hormone response | Evidence remains limited and off-label, but GH may benefit a subset: literature review of 12 treated patients found 58% (7/12) positive response; response was 100% in those with low IGF-1 and 50% in those with normal IGF-1 in the 2024 review dataset; no adverse reactions were reported in that review | Growth hormone treatment candidate NCIT term not confirmed here; IGF-1 biomarker candidate not mapped here | Human case + literature review | Li et al., 2024, https://doi.org/10.1186/s13023-024-03430-4 (pqac-00000000, pqac-00000012) |
| Model systems | Disease mechanism has been studied in zebrafish (ORC1 depletion causing MGS-like growth phenotype; H4K20me2 depletion reducing body size), mouse embryos/fibroblasts (GINS3 Asp24 models with growth retardation, lethality, senescence), budding yeast (GINS2/GINS3 ortholog assays), Xenopus egg extracts (DONSON-dependent CMG assembly), and Drosophila/other systems summarized in reviews | Cell/tissue candidates not fully resolved here; zebrafish NCBI Taxon candidate 7955; mouse 10090; Xenopus laevis 8355; budding yeast Saccharomyces cerevisiae 4932 | Model organism + in vitro + cell-free functional evidence | Kuo et al., 2012, https://doi.org/10.1038/nature10956; McQuaid et al., 2022, https://doi.org/10.1172/jci.insight.155648; Kingsley et al., 2023, https://doi.org/10.1093/nar/gkad694; Nielsen-Dandoroff et al., 2023, https://doi.org/10.1038/s41431-023-01359-z (pqac-00000005, pqac-00000018, pqac-00000006) |
| Epigenetic link | ORC1 BAH domain recognizes H4K20me2, linking histone methylation to replication licensing; loss of this interaction impairs origin occupancy/chromatin loading and can produce an MGS-like growth phenotype in zebrafish | H4K20me2 as histone mark; ORC1 BAH domain | Structural biology + cell biology + zebrafish | Kuo et al., 2012, Nature, published Mar 2012, https://doi.org/10.1038/nature10956 (pqac-00000001) |
| Clinical-trial status | No disease-specific interventional MGORS trial was identified in the retrieved evidence; one broader observational registry is recruiting: Primordial Dwarfism Registry (NCT04569149), observational, target enrollment 200 | ClinicalTrials.gov: NCT04569149 | Registry / observational study | ClinicalTrials.gov entry NCT04569149, recruiting at retrieval time (trial search evidence) |


*Table: This table summarizes high-yield knowledge-base facts for Meier-Gorlin syndrome, including core definition, gene set, mechanism, representative variants, growth data, treatment signals, models, and trial status. It is designed for rapid curation and ontology-aware annotation while avoiding uncertain IDs.*