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ORPHA:753

46,XY difference of sex development due to 5-alpha-reductase 2 deficiency

low confidenceDisorder

Also known as: 46,XY DSD due to 5-alpha-reductase 2 deficiency · 46,XY disorder of sex development due to 5-alpha-reductase 2 deficiency · Pseudovaginal perineoscrotal hypospadias · Steroid 5-alpha-reductase 2 deficiency

Publications

2,934

Trials

0

Interventional, condition-specific

Researchers

722

Distinct authors in sample

Gene link

SRD5A2

Strong

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare difference of sex development (DSD) due to a defect in metabolizing testosterone to dihydrotestosterone and characterized by incomplete intrauterine masculinization which ranges from a female genitalia with a blind vaginal pouch to a fully male with pseudovaginal posterior hypospadias and micropenis.

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 (5)

3-oxo-5 Alpha-steroid Delta 4-dehydrogenase deficiency · 5 Alpha steroid reductase 2 deficiency · Male pseudohermaphroditism due to 5-alpha-reductase 2 deficiency · pseudovaginal perineoscrotal hypospadias · steroid 5-alpha-reductase deficiency

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.”

3/6 stages with a signal

No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.

  1. Gene identifiedPresent

    Strong — SRD5A2

  2. LiteraturePresent

    2,934 matched papers (1,836 in last 10 years) Source

  3. Phenotype characterisedPresent

    19 HPO annotations (e.g. Cryptorchidism; Ambiguous genitalia, male; Perineal hypospadias) Source

  4. Animal modelNot found

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

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialNot found

    No matched interventional trial under our ClinicalTrials.gov rules

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?

Yes — we know a specific gene responsible (SRD5A2).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

19

Associated phenotypes · MONDO:0009923

  • Cryptorchidism
  • Ambiguous genitalia, male
  • Perineal hypospadias
  • Decreased fertility
  • Abnormality of the endocrine system

Showing 5 of 19 — 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)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

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?

2,934

2,934 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.

2,934 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).

1,836 in the last 10 years · low confidence

Phrase hits: 149 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

722

Distinct author names in 149 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
    Wilson JD12 papers · 1996

    Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.

    Papers in Europe PMC
  2. 02
    Imperato-McGinley J9 papers · 2006

    New York Hospital-Cornell University Medical Center, Department of Medicine, NY 10021.

    Papers in Europe PMC
  3. 03
    Griffin JE8 papers · 1993
    Papers in Europe PMC
  4. 04
    Russell DW7 papers · 1996
    Papers in Europe PMC
  5. 05
    Hiort O4 papers · 2013

    Division of Experimental Paediatric Endocrinology and Diabetes, University of Lübeck, Lübeck, Germany. olaf.hiort@uksh.de

    Papers in Europe PMC
  6. 06
    Peterson RE4 papers · 1991
    Papers in Europe PMC
  7. 07
    Sultan C4 papers · 2010

    Pediatric Endocrine Unit, Department of Pediatrics, Hôpital A. de Villeneuve, CHU Montpellier, 34295 Montpellier Cedex, France.

    Papers in Europe PMC
  8. 08
    Davis DL3 papers · 1996
    Papers in Europe PMC
  9. 09
    Gautier T3 papers · 1994
    Papers in Europe PMC
  10. 10
    Leshin M3 papers · 1984
    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).

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.

low 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.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

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 60 · after dedupe 60 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 60 · dropped 0 · fetched 2026-07-29

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).

Uncertain / not reviewed (60)

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 46,XY difference of sex development due to 5-alpha-reductase 2 deficiency — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

Directly listed under NPRD Group 1.

Group 1 — one-time curative treatment

Up to ₹50 lakh per patient

Financial support for treatment at notified Centres of Excellence (figures evolved from the original ₹20 lakh Group-1 ceiling).

Policy figures change. Verify current MoHFW / CoE guidance before relying on any amount. Verify

Centres of Excellence (15)
  • All India Institute of Medical Sciences (AIIMS) — New Delhi, Delhi
  • Maulana Azad Medical College — New Delhi, Delhi
  • Sanjay Gandhi Post Graduate Institute of Medical Sciences — Lucknow, Uttar Pradesh
  • Post Graduate Institute of Medical Education and Research (PGIMER) — Chandigarh, Chandigarh
  • Centre for DNA Fingerprinting & Diagnostics with Nizam’s Institute of Medical Sciences — Hyderabad, Telangana
  • King Edward Memorial Hospital — Mumbai, Maharashtra
  • Institute of Post-Graduate Medical Education and Research (IPGMER) — Kolkata, West Bengal
  • Centre for Human Genetics with Indira Gandhi Hospital — Bengaluru, Karnataka
  • Institute of Child Health and Hospital for Children (ICH & HC) — Chennai, Tamil Nadu
  • All India Institute of Medical Sciences (AIIMS) — Jodhpur, Rajasthan
  • Sree Avittam Thirunal Hospital (SAT), Government Medical College — Thiruvananthapuram, Kerala
  • All India Institute of Medical Sciences (AIIMS) — Bhopal, Madhya Pradesh
  • Regional Institute of Medical Sciences (RIMS) — Imphal, Manipur
  • All India Institute of Medical Sciences (AIIMS) — Patna, Bihar
  • Assam Medical College & Hospital — Dibrugarh, Assam

Voluntary contributions / crowdfunding (separate from CoE funding): https://rarediseases.mohfw.gov.in/

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.

("46,XY difference of sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY difference of the sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY DSD due to 5-alpha-reductase 2 deficiency" OR "46,XY disorder of sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY disorder of the sex development due to 5-alpha-reductase 2 deficiency" OR "Pseudovaginal perineoscrotal hypospadias" OR "Steroid 5-alpha-reductase 2 deficiency" OR "3-oxo-5 Alpha-steroid Delta 4-dehydrogenase deficiency" OR "5 Alpha steroid reductase 2 deficiency" OR "Male pseudohermaphroditism due to 5-alpha-reductase 2 deficiency" OR "steroid 5-alpha-reductase deficiency") OR ("SRD5A2" OR "SRD5A2 syndrome" OR "SRD5A2-related")

Run this search on Europe PMC

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

"46,XY difference of sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY difference of the sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY DSD due to 5-alpha-reductase 2 deficiency" OR "46,XY disorder of sex development due to 5-alpha-reductase 2 deficiency" OR "46,XY disorder of the sex development due to 5-alpha-reductase 2 deficiency" OR "Pseudovaginal perineoscrotal hypospadias" OR "Steroid 5-alpha-reductase 2 deficiency" OR "3-oxo-5 Alpha-steroid Delta 4-dehydrogenase deficiency" OR "5 Alpha steroid reductase 2 deficiency" OR "Male pseudohermaphroditism due to 5-alpha-reductase 2 deficiency" OR "steroid 5-alpha-reductase deficiency"

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

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
  • Publication count (2934) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T15:13:00.364Z