Number of centres planned : 16 centres in France

Type of study / Study design : Research Involving the Human Person category 2.

Multicentric. Prospective

Planning of the study : Total duration: 57,5 months. Recruitment period: 33.5 months. Follow-up time per patients : 2 years

Expected number of cases : The study will involve a maximum of 900 individuals, from 16 centers in France300 family trios (consisting of 150 index cases and their 2 parents, healthy volunteers, N= 450 individuals)

- In the event of unavailability, refusal, non-compliance with an inclusion or exclusion criterion concerning one of the biological parents, only the index case (patient) will be included in the study without his or her parents.

The 300 index cases with ventriculo-arterial discordance will be divided into two groups: 100 double discordance cases and 200 large-vessel transpositions.

These group inclusion targets are theoretical. If the proportion of patients available for inclusion turns out to be higher than expected for one of the groups, the targets may be adjusted, while maintaining a maximum of 300 cases included (corresponding to 900 subjects if all trios are complete).

Patients and their parents will be informed of the study by their referring cardiologist, and their written consent will be obtained.

Translated with DeepL.com (free version)

Treatment, procedure, combination of procedures under consideration :

• Blood samples for genetic analyses collected at the inclusion visit for patients and parents in case of trio families

Schedule of different visits and examinations :

Inclusion visit:

• Collection of demographic, clinical data from the index case and parents
• DNA sampling for genetic research (biocollection) of the index case or family trio
• Completion of the quality of life questionnaire

Annual visit with a 2 years follow-up:

• Retrieval of data from the index case
• Completion of the quality of life questionnaire

Inclusion Criteria:

• Patients with transposition of the great arteries or transposition congenitally corrected of the great arteries with healthy parents and no family history of congenital heart disease (familial trio)
• Or patients with transposition of the great arteries or transposition congenitally corrected of the great arteries with or without a history of congenital heart disease (familial form or sporadic case)
• Affiliated or beneficiaries of a social security scheme or similar
• After obtaining oral consent from patients and/or parents if applicable

Parents (for family trios) :

- Biological parents of the child included in the PRECIPED study

Exclusion Criteria:

• Patients with transposition of the great arteries or transposition congenitally corrected of the great arteries with hypoplastic ventricle or atrioventricular and/or ventriculoarterial valve atresia
• Patient with an identified malformation syndrome
• Patients under guardianship/curatorship
• Patients with State Medical Aid
• Refusal of consent by the patient and/or one of the two parents