Hormonal Sensitivity in Patients With Noonan and LEOPARD Syndromes

Institut National de la Santé Et de la Recherche Médicale, France27 enrolled

Overview

Noonan and LEOPARD syndromes share, with variable severity, different clinical traits, notably craniofacial manifestations, cardiopathies, short stature, and juvenile cancers. The main genetic cause of these syndromes is missense mutation of the gene encoding the ubiquitous tyrosine phosphatase Shp2, found in more than half the patients with NS and in 80% of LS cases. Shp2 plays pivotal roles in development, growth, and metabolism by regulating key signalling pathways (Ras/Mitogen activated protein kinase (MAPK), Phosphoinositide-3 Kinases (PI3K)/Akt) in response to growth factors/hormones. Deregulation of these signalling pathways has been causally linked to NS and LS pathophysiology. This project aims at better understanding hormonal sensitivity abnormalities in patients with Noonan syndrome (NS) or LEOPARD syndrome (LS) caused by mutations of the tyrosine phosphatase Shp2. To reach this goal, the investigators will take advantage of different tissues (fibroblasts ± adipocytes) from patients with NS / LS compared to healthy controls. All patients will have a skin biopsy and only patients about to undergo surgery will have a adipose tissue biopsy.

The activation of different signaling pathways (Ras/MAPK, PI3K/Akt) in response to growth factors/hormones (growth hormone, insulin) in fibroblasts and/or in adipocytes from patients with NS or LS will be compared to those of healthy subjects. These data will be correlated to clinical, hormonal, and biochemical characteristics of patients

Study Type

OBSERVATIONAL

Enrollment

Conditions

Noonan Syndrome LEOPARD Syndrome

Eligibility

Medical Language ↔ Plain English

Inclusion Criteria: Patients with Noonan syndrome (NS) or LEOPARD syndrome (LS): * female or male * age between 5 to 15 years * clinical diagnosis of NS or LS according to published criteria * signed informed consent of parents Healthy controls: * female or male * age between 5 to 15 years * no personal history of syndrome or chronic disease * planned surgical procedure * signed informed consent of parents Exclusion Criteria: * age below 5 or above 15 years * pregnancy In healthy controls: syndromic or chronic disease

Outcomes

Primary Outcomes

Phosphorylation of Erk and Akt in fibroblasts

To evaluate different signaling pathways activation (Ras/MAPK, PI3K/Akt) in response to growth factors/hormones (growth hormone, insulin) in fibroblasts from patients with NS or LS compared to healthy controls

Time frame: Baseline

Secondary Outcomes

Phosphorylation of Erk and Akt in adipocytes

To evaluate different signaling pathways activation (Ras/MAPK, PI3K/Akt) in response to growth factors/hormones (growth hormone, insulin) in adipocytes from patients with NS or LS compared to healthy controls