| Disease / focus | Main synonyms | Causal gene | Inheritance | Key clinical features (human) | Key clinical features (mouse) | Key diagnostic approaches | Notable data points | Evidence (year; URL) |
|---|---|---|---|---|---|---|---|---|
| Lysosomal acid phosphatase deficiency | Total lysosomal acid phosphatase deficiency; LAP deficiency; lysosomal acid phosphatase (LAP) deficiency | **ACP2** | Autosomal recessive, inferred from affected sibs and intermediate parental enzyme activity | Early-infantile disease with progressive lethargy, hypotonia/opisthotonus, intermittent vomiting, terminal bleeding, death in the first year of life | Not reported in this human review row | Lysosomal acid phosphatase enzyme assay showing complete deficiency in affected individuals; family studies showing intermediate activity in parents; modern workup would add molecular **ACP2** testing | Human disease appears ultra-rare; no prevalence estimate available; only a few historical families described | Bull et al. 2002; https://doi.org/10.1136/mp.55.2.65 (pqac-00000003) |
| Lysosomal acid phosphatase deficiency (historical human reports summarized in mouse paper) | LAP deficiency; complete lysosomal phosphatase deficiency | **ACP2** | Autosomal recessive, suggested by family pattern and parental intermediate enzyme activity | Progressive lethargy, opisthotonus, bleeding, death within the first year of life | — | Enzyme assay in patient tissues/cells; carrier detection by intermediate activity in parents | Authors noted that “no further patients have been described” after early reports, underscoring extreme rarity | Saftig et al. 1997; https://doi.org/10.1074/jbc.272.30.18628 (pqac-00000002) |
| ACP2/LAP-deficient knockout mouse | Lysosomal acid phosphatase deficiency model; LAP-deficient mouse | **Acp2** | Targeted biallelic loss in model organism | — | Progressive lysosomal storage in kidney podocytes and tubular epithelial cells; CNS storage in microglia, ependymal cells, astroglia; progressive astrogliosis/microglial activation; skeletal deformity/kyphoscoliosis; occasional generalized seizures | Gene knockout confirmation; absent LAP enzyme activity; histology/electron microscopy; radiology | ~7% (19/270) developed generalized tonic-clonic seizures after ~8 weeks; bone changes evident from 6 months onward | Saftig et al. 1997; https://doi.org/10.1074/jbc.272.30.18628 (pqac-00000000, pqac-00000004) |
| Spontaneous **Acp2** mutant mouse (nax) | Naked-ataxia; nax | **Acp2** | Autosomal recessive in mouse colony/model context | — | Growth retardation, delayed hair appearance, ataxic gait, severe cerebellar hypoplasia, absent/hypoplastic vermis, reduced granule cells, multilayered Purkinje cells, poor dendritic development, disorganized Bergmann glia, early death | Phenotyping plus mutation analysis in the model; neuropathology/histology | Weight at P15 ~4 g vs ~8 g in wild type; death usually around P18–P26 | Jiao 2017 thesis excerpt; URL not available in retrieved metadata (pqac-00000001) |
| Mouse cerebellar development study in **Acp2** mutant | ACP2 mutant cerebellar model; nax | **Acp2** | Recessive model organism mutation | — | Severe cerebellar cortex defect with striking reduction in granule cells; SHH pathway dysregulation; reduced MYCN at P10; impaired protein synthesis machinery implicated | Brain histology, BrdU assays, Western blot, RT-qPCR | Mechanistic evidence links ACP2 loss to abnormal cerebellar development rather than a single isolated pathway | Jiao et al. 2021; https://doi.org/10.3390/ijms22062994 (pqac-00000011) |
| Practical diagnostic summary for suspected human disease | ACP2 deficiency; LAP deficiency | **ACP2** | Likely autosomal recessive | Infantile neurodevelopmental/systemic deterioration in reported historical cases | Animal data support kidney/CNS susceptibility and can guide organ surveillance hypotheses | 1) Biochemical lysosomal acid phosphatase assay in leukocytes/fibroblasts/tissue; 2) confirmatory **ACP2** sequencing/exome/genome testing; 3) pathology if needed for lysosomal storage assessment | No disease-specific treatment or ACP2-targeted clinical trials identified in retrieved evidence | Human historical reports summarized in Bull 2002 and Saftig 1997; no direct ACP2 therapy found (pqac-00000003, pqac-00000002, pqac-00000012) |
| Recent ACP2-related biology relevant to disease mechanism | Lysosomal acid phosphatase 2; ACP2 | **ACP2** | Not a disease-frequency study | No direct patient data | ACP2 participates in lysosomal mannose-6-phosphate dephosphorylation and broader lysosome biology; depletion can alter innate antiviral IFN-I responses in cell models | Research assays only; not a clinical diagnostic standard | ACP2 knockdown increased VSVΔ51 infectivity by ~19.5-fold / >20-fold in 2024 screening study, highlighting current mechanistic interest though not a therapy for deficiency | Wong et al. 2024; https://doi.org/10.1038/s41598-024-76855-3 (pqac-00000009, pqac-00000010) |


*Table: This table compacts the key disease-level facts for lysosomal acid phosphatase deficiency, separating sparse historical human evidence from stronger mouse-model data. It is useful for quickly extracting nomenclature, inheritance, phenotype, diagnostics, and major quantitative observations with citations.*