| Subtype | Typical onset window | Hallmark clinical features | Common complications (cardiac/renal/neuro/ocular) | Example case data with quantitative values if available | Suggested HPO terms |
|---|---|---|---|---|---|
| Early infantile | Prenatal/in utero or within first 3 months of life; often perinatal presentation (pqac-00000039, pqac-00000045, pqac-00000046) | Hydrops fetalis/non-immune hydrops, coarse facies, hepatosplenomegaly/visceromegaly, psychomotor delay, hypotonia, skeletal dysplasia/dysostosis multiplex, edema/ascites, respiratory distress; cherry-red spots may occur (pqac-00000039, pqac-00000042, pqac-00000043, pqac-00000046) | Cardiac: cardiomyopathy, reduced cardiac contractility, severe biventricular dysfunction, possible heart failure; Renal: nephrocalcinosis, possible renal failure; Neuro: developmental delay, hypotonia, periventricular calcifications/brain MRI changes; Ocular: cherry-red spot, lens/corneal clouding, disk pallor (pqac-00000039, pqac-00000040, pqac-00000043, pqac-00000046) | Review of 4 EI cases: fetal hydrops 2/4, edema 3/4, psychomotor delay 4/4, hypotonia 3/4, coarse facies 4/4, hepatosplenomegaly 2/4, cardiac involvement 2/4; fibroblast GLB1 example 27 nmol/mg/h (normal 391-2397), NEU1 0.1 nmol/mg/h (normal 5.1-48); one newborn case progressed to LVEF 25% and died on day 47 (pqac-00000046, pqac-00000008, pqac-00000025) | HP:0001789 Hydrops fetalis, HP:0000175 Cleft/abnormal face-coarse facies surrogate coarse facial features, HP:0002240 Hepatosplenomegaly, HP:0001263 Global developmental delay, HP:0001252 Hypotonia, HP:0002652 Skeletal dysplasia, HP:0001638 Cardiomyopathy, HP:0000518 Cataract/lens opacity surrogate for lens clouding, HP:0000529 Cherry red spot of the macula |
| Late infantile | After 6 months to first years of life; within first year in some summaries; around ~2 years in one recent review/case summary (pqac-00000039, pqac-00000041, pqac-00000045) | Short stature/growth retardation, coarse facial features, dysostosis multiplex, hepatosplenomegaly/visceromegaly, cardiac involvement, hearing loss, decreased visual acuity; corneal clouding and cherry-red spots may occur; neurological signs are less prominent and seizures/myoclonus/ataxia are rare (pqac-00000039, pqac-00000042, pqac-00000045) | Cardiac: valvular disease, hypertrophy/regurgitation/stenosis; Renal: renal findings reported in some cases; Neuro: occasional psychomotor retardation/intellectual disability, generally less severe than juvenile/adult neurologic disease; Ocular: corneal clouding, cherry-red spots, poor vision (pqac-00000039, pqac-00000040, pqac-00000041) | Bahraini founder-variant cases: short stature, coarse facies, poor vision, skeletal deformities; Patient 3 had mild LVH with aortic and mitral regurgitation plus diffuse angiokeratomas; review example late-infantile case had coarse facies, hepatosplenomegaly, growth retardation, renal findings with preserved neurological development (pqac-00000026, pqac-00000024, pqac-00000040) | HP:0004322 Short stature, HP:0000280 Coarse facial features, HP:0002650 Spondylodysplasia/dysostosis multiplex related skeletal anomaly, HP:0002240 Hepatosplenomegaly, HP:0001631 Abnormality of cardiac valves, HP:0000365 Hearing impairment, HP:0000505 Visual impairment, HP:0000520 Corneal opacity, HP:0000529 Cherry red spot of the macula |
| Juvenile/adult | Usually adolescence; average onset about 16 years in one review (pqac-00000039, pqac-00000041, pqac-00000045) | Myoclonus, cerebellar ataxia, seizures, progressive intellectual disability/neurological deterioration, angiokeratoma, coarse facies, vertebral/skeletal changes, cherry-red spots, vision and hearing loss; visceromegaly usually absent (pqac-00000039, pqac-00000042, pqac-00000045) | Cardiac: valvular regurgitation can occur; Renal: not a dominant feature in retrieved evidence; Neuro: action myoclonus, ataxia, cognitive impairment, cerebral/cerebellar atrophy; Ocular: cherry-red spot, night blindness/vision loss, corneal clouding in some summaries; Hearing loss common (pqac-00000039, pqac-00000028, pqac-00000041) | Japanese adult case: WAIS-III IQ 64 (VIQ 83, PIQ 52), MMSE 27/30; fibroblast β-galactosidase 111.2 nmol/mg protein/h (normal ~401 ± 184.8), neuraminidase 0 (normal ~25.0 ± 17.0); MRI showed mild cerebral/cerebellar cortical atrophy; echocardiography showed moderate aortic and mitral regurgitations (pqac-00000028) | HP:0001336 Myoclonus, HP:0001251 Ataxia, HP:0001250 Seizure, HP:0001249 Intellectual disability, HP:0000988 Angiokeratoma, HP:0000529 Cherry red spot of the macula, HP:0000505 Visual impairment, HP:0000365 Hearing impairment, HP:0002650 Vertebral anomaly/skeletal dysplasia surrogate |


*Table: This table summarizes the clinical phenotype spectrum of galactosialidosis by subtype, including onset windows, hallmark findings, complications, quantitative examples, and suggested HPO mappings. It is useful for disease curation, differential diagnosis, and structured phenotype annotation.*