Quantification of Elastin Markers Synthesis in Williams-Beuren Syndrome and 7q11.23 Micro-duplication Syndrome (ELAST7)

Quantification of Elastin Markers Synthesis in Williams-Beuren Syndrome and 7q11.23 Micro-duplication Syndrome

Quantification of Elastin Markers Synthesis in Williams-Beuren Syndrome and 7q11.23 Micro-duplication Syndrome

Introduction: Williams-Beuren syndrome is a rare genetic disorder caused by a 7q11.23 microdeletion. The phenotype associates vasculopathy (arterial stenosis, hypertension), dimorphism and intellectual disability. Microdeletion includes several genes: ELN encodes for elastin and the haplo-insufficiency (only 1 functional copy) causes vasculopathy. The primary objective is to quantify plasma and urinary levels of elastin peptides in Williams-Beuren patients and 7q11.23 micro-duplication syndrome patients in order to correlate the levels of these markers with the number of copies of ELN gene (proportional positive relationship "gene copy number - circulating levels of markers) Materials and Methods: This prospective study will be carried out in Lyon at the "Hôpital Femme-Mère-Enfant" for 2 years. 3 groups of patients will be studied: Williams-Beuren patients (N=20), micro-duplication 7q11.23 syndrome patients (N=10) and healthy patients (N=60). Subjects will be followed for 1 day. Clinical examination (weight, height, blood pressure) and biological sample collection (blood and urine sample) will be carry out for Williams Beuren and micro-duplication 7q11.23 patients group. A large majority of visits will be part of patients' usual care. A large part of patients are systematically seen in consultation once a year. For healthy group, only biological sample collection will be carry out. The PE concentrations will be assessed and compared between the three groups of patients.

Subjects aged from 3 months to 60 years with a diagnosis confirmed with FISH of Williams Beuren syndrome.

Subjects aged from 3 months to 60 years with a diagnosis confirmed with CGHarray of micro-duplication 7q11.23 syndrome.

Only one visit for each participant : A large majority of visits will be part of patients' usual care Medical examination : birth, weight, gender, blood pressure, medical history Urine and blood samples

To quantify plasma level of elastin peptides in participants in order to correlate the levels of these markers with the number of copies of ELN gene (proportional positive relationship "gene copy number - circulating levels of markers). The primary endpoint will be assessed by measuring the blood level of PE between groups

To quantify urinary level of elastin peptides in participants in order to correlate the levels of these markers with the number of copies of ELN gene (proportional positive relationship "gene copy number - circulating levels of markers). The primary endpoint will be assessed by measuring the urinary level of PE between groups

Blood levels of PE in the samples of patients who participated in the minoxidil clinical trial will be compare to those of participants of this study

Urinary levels of PE in the samples of patients who participated in the minoxidil clinical trial will be compare to those of participants of this study

Inclusion Criteria: Age : from 3 months to 60 years old Williams Beuren group : Diagnosis confirmed with FISH Micro-duplication 7q11.23 group : Diagnosis confirmed with CGHarray Healthy Group : no cardiovascular and neurological medical history Informed consent Exclusion Criteria: No social insurance Subject under judicial protection Subject participating in another research including an exclusion period still in progress