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ORPHA:93160

Hypocalcemic vitamin D-resistant rickets

high confidenceDisorder

Also known as: HVDRR · Hereditary vitamin D-resistant rickets · VDDR II · VDRR II · Vitamin D-dependent rickets type II · Vitamin D-resistant rickets type II

Publications

615

72th percentile

Trials

0

Interventional, condition-specific

Researchers

859

Distinct authors in sample

Gene link

—

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare genetic, disorder of vitamin D metabolism characterized by hypocalcemia, severe rickets and in many cases alopecia.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (9)

VDDR2 · hereditary 1,25 dihydroxyvitamin D-resistant rickets with abnormal Vitamin D receptor · hereditary vitamin D-resistant rickets · hypocalcemic vitamin D-resistant rickets · vitamin D dependent rickets 2 · vitamin D receptor deficiency · vitamin D-dependent rickets type II · vitamin D-dependent rickets, type 2 · vitamin D-resistant rickets type II

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    615 matched papers (251 in last 10 years) Source

  3. Phenotype characterisedPresent

    91 HPO annotations (e.g. Recurrent fractures; Osteolysis; Genu valgum) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationPresent

    2 FDA designations (1 FDA orphan-indication approval) — e.g. Secalciferol Source

  6. Interventional trialPartial

    None under the specific name; 26 for broader category rickets

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

91

Associated phenotypes · MONDO:0019642

  • Recurrent fractures
  • Osteolysis
  • Genu valgum
  • Hypocalcemia
  • Abnormal hip bone morphology

Showing 5 of 91 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

2

Designations · 1 with FDA orphan-indication approval

  • FDA SecalciferolFamilial Hypophosphatemic Rickets · 1993-07-26 · Not FDA Approved for Orphan Indication
  • FDA burosumab-twza (Crysvita)X-Linked Hypophosphatemia vitamin d-resistant rickets X-Linked Hypophosphatemia · 2009-12-14

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

615

615 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

615 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

251 in the last 10 years · high confidence · 72th percentile (publications denominator)

Phrase hits: 615 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

859

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Feldman D14 papers · 2014

    Department of Medicine, Stanford University , Stanford, CA, USA.

    Papers in Europe PMC
  2. 02
    Malloy PJ13 papers · 2014

    S025 Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305-5103, USA. pjmalloy@stanford.edu

    Papers in Europe PMC
  3. 03
    Stich B10 papers · 2026

    Institute of Quantitative Genetics and Genomics of Plants, Heinrich Heine University Duesseldorf, Duesseldorf, Germany.

    Papers in Europe PMC
  4. 04
    Wang J8 papers · 2014

    Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.

    Papers in Europe PMC
  5. 05
    Kongsbak-Wismann M6 papers · 2025

    The LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.

    Papers in Europe PMC
  6. 06
    van Inghelandt D6 papers · 2026

    Institute for Breeding Research on Agricultural Crops, Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Sanitz, 18190, Germany.

    Papers in Europe PMC
  7. 07
    Gao Y5 papers · 2026

    State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 235 West University Road, Hohhot, 010021, China.

    Papers in Europe PMC
  8. 08
    Kitanaka S5 papers · 2020

    Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Japan.

    Papers in Europe PMC
  9. 09
    Shrestha A5 papers · 2026

    Institute for Quantitative Genetics and Genomics of Plants, Biology Department, Heinrich Heine University, Dusseldorf, Germany.

    Papers in Europe PMC
  10. 10
    Tiosano D5 papers · 2021

    Division of Pediatric Endocrinology, Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel; Bruce Rappaport Faculty of Medicine, The Technion, Haifa, Israel. Electronic address: d_tiosano@rambam.health.gov.il.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present). 26 trials are registered for rickets, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 11 September 2026 · last trial check 11 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

high confidence · 38.6th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

26 interventional trials matched rickets, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: rickets

26

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-30

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Hypocalcemic vitamin D-resistant rickets — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Hypocalcemic vitamin D-resistant rickets" OR "HVDRR" OR "Hereditary vitamin D-resistant rickets" OR "VDDR II" OR "VDRR II" OR "Vitamin D-dependent rickets type II" OR "Vitamin D-resistant rickets type II" OR "VDDR2" OR "hereditary 1,25 dihydroxyvitamin D-resistant rickets with abnormal Vitamin D receptor" OR "vitamin D dependent rickets 2" OR "vitamin D receptor deficiency" OR "vitamin D-dependent rickets, type 2"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Hypocalcemic vitamin D-resistant rickets" OR "HVDRR" OR "Hereditary vitamin D-resistant rickets" OR "VDDR II" OR "VDRR II" OR "Vitamin D-dependent rickets type II" OR "Vitamin D-resistant rickets type II" OR "VDDR2" OR "hereditary 1,25 dihydroxyvitamin D-resistant rickets with abnormal Vitamin D receptor" OR "vitamin D dependent rickets 2" OR "vitamin D receptor deficiency" OR "vitamin D-dependent rickets, type 2"

Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"rickets"

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T04:07:46.595Z