ALMS and BBS syndromes are rare diseases with overlapping features of multiple sensory and metabolic impairments, including diabetes mellitus. There are to date no specific treatments available and limited information on the natural history of the diseases. the investigators aim to establish a French cohort for these diseases to improve patient care and assess the effect of actual therapies on quality of life.

The purpose of this study is to establish a cohort of Bardet-Bield syndrome (BBS) and ALström syndrome (ALMS) patients in order to formalize and address questions concerning the in-depth natural clinical and biological history of the disease on the long term for a given patient, establish the impact on the quality of life of various clinical manifestations

Inclusion Criteria:

• Patients of both sex

• Age minimum*

• patients with social protection

• Written informed consent form signed prior initiating any trial related procedure:

  • by > 18-year old patients
  • by both parents for minor patients > 4 months or legal representative for protected adults, and by minor and protected adults patients if able to understand and/or give their assent.
  • For foreign patients, a third party will translate, if required, the information prior to the consent.

• a diagnosis of BBS or ALMS based on molecular assessment or clinical evaluation/or patient with mutation and none of the diagnosis criteria

• and/or an identified mutation in BBS genes or ALMS1 gene

  • The inclusion of children is essential to a cohort study that is attempting an early identification of visual, metabolic and renal abnormalities. Many of the age-dependent manifestations of BBS develop during childhood and the average age of diagnosis is 9.2 years

Exclusion Criteria:

• Serious active intercurrent pathology that may impact the collected data
• Patient under judicial protection
• Participation in another interventional clinical trial which includes an exclusion period
• Non protected adult with difficulty of comprehension, or inability to understand the delivered information (emergency situation ...).