Clinical trial NCT02525328: Genome Study in Constitutional Thinness
Official title: Genome Study in Constitutional Thinness
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Thinness
Leanness
Keywords: Constitutional Thinness
linkage study
genome wide scan (GWAS)
Lead sponsor: Centre Hospitalier Universitaire de Saint Etienne
Sponsor class: OTHER
First posted: 2015-08-17
Enrollment: 210
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: FAMILY_BASED
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Fifty families including at least 2 well phenotyped CT index case (grade 2 or 3 of thinness according WHO classification) and members without CT.

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: chromosome regions' abnormalities
timeFrame: day 1
Secondary outcomes:
measure: genetic markers
timeFrame: day 1
Other outcomes:
Locations:
city: Saint-Etienne
country: France
facility: CHU Saint-Etienne
Study officials:
affiliation: CHU SAINT-ETIENNE
name: Bruno Estour, MD PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: CHU SAINT-ETIENNE
name: Bogdan GALUSCA, MD PhD
role: PRINCIPAL_INVESTIGATOR
References: