Genome Study in Constitutional Thinness (GENOSCANN)

Centre Hospitalier Universitaire de Saint Etienne

Status: Completed

Conditions: Leanness; Thinness

Treatments: Other: blood or saliva specimen

Study type: Observational

Funder types: Other

Identifiers

NCT02525328

2010-A00051-38 (Other Identifier)

0908129

Details and patient eligibility

About

Constitutional thinness (CT) is a recently defined entity as a differential diagnosis of anorexia nervosa (AN), considered to be the most frequent cause of low body mass index (BMI) in young women. CT subjects present no AN psychiatric traits, preserved menses, no biological signs of undernutrition and balanced energy metabolism despite a Body Mass Index (BMI) <17 kg / m².

CT familial aggregation, low body mass without a hormonal explanation, and specific appetite regulation profile suggest a specific genetic profile in these subjects.

Objective: A family linkage study in order to identify genes involved in the constitutional thinness phenotype by using genome wide scan (GWAS) techniques Studied population: Fifty families including at least one well phenotyped CT index case (grade 2 or 3 of thinness according WHO classification). Blood or saliva is sampled for DNA extraction.

Perspectives: Revealing eventual abnormalities could lead to a more precise diagnosis of constitutional thinness and new hypothesis in understanding extreme bodyweight mechanisms.

Enrollment: 210 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• For all subjects:

  • age > 18 yrs
  • affiliation to health insurance
  • member of a family including at least 2 CT members and overall 3 evaluable members over 2 generations
  • written and signed consent

• For CT subjects :

  • grade 2 or 3 of thinness according WHO classification
  • women, BMI < 17 kg/m² at 20-30 yrs or < 19 for older subjects
  • men, BMI < 18 kg/m² at 20-30 yrs or < 20 for older subjects
  • absence of DSM criteria for anorexia nervosa
  • young women : normal menses and fat mass percentage 15 % ; absence of DSM criteria for anorexia nervosa
  • men : normal testosterone level

• For subjects without CT :

  • women, BMI > 19 kg/m²
  • men, BMI > 20 kg/m²

Exclusion criteria

• CT subjects:

  • smoking > 5 cigarettes / day
  • history of emaciating pathologies
  • intense physical activity > 7 hours / week

• For all subjects :

  • refuse of written consent

Trial design

210 participants in 2 patient groups

CT subjects

Description:

blood or saliva specimen

Treatment:

Other: blood or saliva specimen

subjects without CT

Description:

blood or saliva specimen

Treatment:

Other: blood or saliva specimen