Genetic testing: what the GP can order, and how (consent, certificate, informing relatives)

Genetics · Symptom or situation · updated 2026-10-30

BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.

Frequency: In France, 496 584 people had a postnatal constitutional genetic test in 2017 (latest Agence de la biomédecine report read) ^[1].

Symptomatic patient: targeted genetic test ordered in the community

Written consent of the patient (or of the holders of parental authority), usually on the laboratory's form
Signed statement by the prescriber certifying the information given (copy kept in the record)
Indication, clinical information, family history (family tree if done), recent treatments

Testing for the HFE C282Y mutationif neededNABM coverage (code 8000) after a transferrin saturation > 45% confirmed on a second sample; see the page hemochromatose ^[2].
Factor V Leidenif neededCodes 1029 and 1030 to be prescribed according to the guidelines on inherited thrombophilia, with clinical context and family history specified: see the page thrombophilie ^[2].
Factor II G20210A mutationif neededCodes 1029 and 1030 to be prescribed according to the guidelines on inherited thrombophilia, with clinical context and family history specified: see the page thrombophilie ^[2].
Constitutional karyotype on bloodif neededCode 0901: authorised laboratory, approved practitioner, information attestation and consent required ^[2]; see for example the page fausses-couches-repetition.

Detailed explanation and international comparison (in French): read it in English (machine translation)

Genetic tests bought on the internet (health, genealogy, "recreational DNA"): prohibited in France for the person who requests them, fine of 3 750 €; results without medical interpretation or guaranteed confidentiality ^[9,20].
Susceptibility tests (low-effect polymorphisms): contribution to risk generally minor, benefit-risk balance often unfavourable ^[4].
Preconception genetic carrier screening in the general population: not authorised in France outside a known familial genetic disease or warning signs ^[16].
Genetic testing in an asymptomatic minor without immediate medical benefit (carrier status, adult-onset disease with no prevention): postpone until adulthood ^[3,4].

No genetic test prescribed in the community: refer to a genetics consultation (multidisciplinary team declared to the Agence de la biomédecine)
Send a copy of the index case's genetic report (familial abnormality, laboratory) if the relative has it

Detailed explanation and international comparison (in French): read it in English (machine translation)

Sources (21)