| Observed phenotype | Evidence-informed onset/course and impact | Verified HPO ID | Frequency |
|---|---|---|---|
| Cleft lip and/or palate | Congenital, generally stable structural anomaly; may impair feeding, speech, hearing, and facial development and require staged surgical repair. (pqac-00000018, pqac-00000025) | Cleft lip — HP:0410030; cleft palate — HP:0000175 | Not reliably established; published cases only; characteristic but not universal. |
| Pigmentary retinopathy | Congenital or recognized in childhood; may remain stable with preserved vision, but longitudinal ophthalmic surveillance is warranted. (pqac-00000002, pqac-00000058) | HP:0000580 | Not reliably established; published cases only; characteristic but not universal. |
| Cholestasis | Usually neonatal or infantile; severity ranges from persistent biochemical disease to progressive jaundice, pruritus, malnutrition, portal hypertension, and liver failure. (pqac-00000022, pqac-00000033) | HP:0001396 | Not reliably established; published cases only; recurrent core manifestation. |
| Biliary atresia | Congenital hepatobiliary malformation presenting in infancy; may cause severe obstructive liver disease and require surgical or transplant evaluation. (pqac-00000025, pqac-00000058) | HP:0005912 | Not reliably established; published cases only; not universal. |
| Absent gallbladder | Congenital imaging or operative finding; may accompany severe biliary maldevelopment and cholestasis. The 2026 example carried a MED12 VUS and is supportive, not genetically definitive. (pqac-00000002, pqac-00000033) | HP:0011467 | Not reliably established; published cases only; rare reported phenotype. |
| Intestinal malrotation | Congenital; may cause neonatal intestinal obstruction and require a Ladd procedure, with substantial acute surgical morbidity. (pqac-00000018, pqac-00000046) | HP:0002566 | Not reliably established; published cases only; characteristic but not universal. |
| Choledochal cyst | Congenital biliary anomaly; may coexist with progressive cholestasis and cirrhosis and has been identified during liver transplantation. (pqac-00000019, pqac-00000046) | HP:0100890 | Not reliably established; published cases only; rare reported phenotype. |
| Hepatic fibrosis | Begins in infancy in severe cases and may progress to bridging fibrosis or cirrhosis, impairing growth and liver function. (pqac-00000018, pqac-00000033) | HP:0001395 | Not reliably established; published cases only; severity is variable. |
| Hepatic failure | Advanced outcome of progressive hepatobiliary disease; may necessitate liver transplantation and can be fatal without timely treatment. The 2026 VUS case must not be counted as molecularly confirmed. (pqac-00000022, pqac-00000023) | HP:0001399 | Not reliably established; published cases only; severe but not universal. |
| Hydronephrosis | Congenital urinary-tract manifestation; may reflect obstruction or ectopic/abnormal ureters and predispose to recurrent infection and renal procedures. (pqac-00000019, pqac-00000058) | HP:0000126 | Not reliably established; published cases only; not universal. |
| Vesicoureteral reflux | Congenital urinary dysfunction; increases urinary-tract infection risk and may require urologic surveillance or intervention. (pqac-00000003, pqac-00000058) | HP:0000076 | Not reliably established; published cases only; not universal. |
| Hearing impairment | Congenital or childhood-onset, including severe bilateral sensorineural loss; may delay speech and require cochlear implantation. (pqac-00000004, pqac-00000058) | HP:0000365 | Not reliably established; published cases only; rare reported phenotype. |
| Congenital diaphragmatic hernia | Prenatal or neonatal structural anomaly with potential respiratory compromise; represents an expanded phenotype rather than a defining feature. (pqac-00000032, pqac-00000058) | HP:0000776 | Not reliably established; published cases only; rare and not universal. |


*Table: Compact phenotype annotations for Hardikar syndrome using HPO identifiers explicitly reported in the case-review literature. Frequencies remain unquantified because evidence comes from small, ascertainment-biased published cases; the 2026 MED12 VUS case is not treated as genetically confirmed.*