Evidence: well sourced. Imported from the supplied 65-Case Master Edition, dated September 19, 2026. Source links and classifications are retained as an attributed case account; import is not an independent source review.
Case at a glance
- Case number
- 043
- Date / range
- Historical treatment / later comparisons
- Sector
- Reproductive and heritable genetics
- Genetic asset
- Donor records and genetic kinship evidence
- Security principle
- Genetic Auditability of Reproductive Systems
Event summary
DNA comparisons indicated that Dutch fertility doctor Jan Karbaat fathered numerous children conceived at his clinic, illustrating how genetic matching can expose hidden substitution and systemic donor-record failures decades later.
Source: pmc.ncbi.nlm.nih.gov — Jan Karbaat And The Dutch Donor Registry Failure source 1.
The case in context
The Karbaat case involved efforts to establish biological relationships despite incomplete or unreliable clinic records. Court-authorized comparisons and later testing brought genetic evidence to questions that the original documentation had not resolved.
The number of identified relatives can change as more people test, so a stable case should not depend on an undated headline count. The distinctive institutional question is how donor records, limits, and oversight work across a system. Genetic auditability may expose a failure long after the original clinical process has ended.
Acquisition and processing
clinic donor process → undisclosed provider substitution → fragmented records → consumer testing → sibling network → court-ordered comparison → system reform
The sequence of events
- clinic donor process
- undisclosed provider substitution
- fragmented records
- consumer testing
- sibling network
- court-ordered comparison
- system reform
What became inferable or exposed
Donor records and genetic kinship evidence
DNA comparisons indicated that Dutch fertility doctor Jan Karbaat fathered numerous children conceived at his clinic, illustrating how genetic matching can expose hidden substitution and systemic donor-record failures decades later.
Affected parties and consent
- Direct parties
- Patients and donor-conceived people
- Indirect parties
- Relatives and connected participants may be relevant where the asset contains relationship information.
- Direct count
- Unknown / not assigned
- Indirect count
- Unknown / not assigned
- Consent status
- Consent depends on the intervention and the identity of the reproductive material. A substitution or undisclosed intervention changes what was authorized.
Security dimensions
Confidentiality
The confidentiality question concerns donor records and genetic kinship evidence. Exposure and further inference must be distinguished from the fact of collection or availability.
Integrity
The integrity question is whether the described material, permissions, processing, or interpretation can be relied upon. Genetic Auditability of Reproductive Systems identifies the particular boundary examined here.
Availability
Access and continuity are assessed for the described event; potential effects are not presented as confirmed outages or losses.
Provenance
The relevant chain follows donor records and genetic kinship evidence through the stages shown below. Missing public detail is not proof that internal records did not exist.
Consent, persistence, and relational exposure
Consent
Consent depends on the intervention and the identity of the reproductive material. A substitution or undisclosed intervention changes what was authorized.
Persistence
Later reuse depends on the actual asset and links to other records; no future misuse is asserted.
Relational exposure
Relatives and connected participants may be relevant where the asset contains relationship information.
Case-specific assessment
integrity/provenance critical; consent critical; persistence maximal; relational exposure high.
GeneticSecurity.org analysis
Genetic Exposure Radius
No single level is assigned where the supplied dossier gives a range, conditional outcome, or broad institutional consequence. The affected parties and proposed assessment are shown separately.
Confidence: not assigned. Classification: GeneticSecurity.org analysis.
Genetic Persistence Risk
Persistence depends on the specific biological material or information retained. A potential effect is not treated as an observed genomic disclosure.
Confidence: not assigned. Classification: GeneticSecurity.org analysis.
Genetic Provenance Integrity
A numeric provenance level is not inferred from the existence of a source or court record. It requires evidence of the relevant custody and processing controls.
Confidence: not assigned. Classification: GeneticSecurity.org analysis.
Proposed classification and its limits
Suggested GER: GER-3. Suggested GPR: GPR-5. Suggested GPI: GPI-0/1 for original clinical records.
These are proposed classifications from the supplied case dossier. Conditional scores describe an assumed exposure; they are not evidence that it occurred. A single numeric value is left unassigned when the asset or outcome is not sufficiently bounded.
What this case does not prove
This case should not be merged with unrelated donor cases or treated as support for an undated speculative offspring count.
Mitigations and lessons
- National donor registries
- Hard offspring limits
- Cross-clinic deduplication
- Immutable provenance
- Audit sampling
- Recipient access rights
- Long retention of reproductive records
Primary sources
No additional source listed. See the evidence notes for limitations.
Secondary sources
Policy and standards
Genetic Security Policy and StandardsReview and correction history
Source edition: September 19, 2026. Imported case account; no substantive corrections recorded.
Correction policy and logCite this case
GS-CASE-043. Jan Karbaat: The Clinic Records Said Donor; DNA Said Doctor. GeneticSecurity.org. https://geneticsecurity.org/cases/043-jan-karbaat-fertility-dna-case/