Cortisol and behavior in fragile X syndrome

Area of Science:

• Neuroscience
• Endocrinology
• Genetics

Background:

• Fragile X syndrome is a genetic disorder often associated with behavioral challenges like social anxiety and hyper-arousal.
• Cortisol, a key stress hormone, plays a role in the body's response to stress.
• The relationship between adrenocortical activity and the fragile X neurobehavioral phenotype requires further investigation.

Purpose of the Study:

• To investigate whether children with fragile X syndrome have elevated salivary cortisol levels.
• To examine the association between adrenocortical activity and the behavioral phenotype in fragile X syndrome.

Main Methods:

• Salivary cortisol samples were collected from 109 children with fragile X and their unaffected siblings during evaluations and on non-school days.
• Cognitive assessments, structured social challenge tasks, and measures of genetic, environmental, and service factors were administered.
• Linear mixed-effects and hierarchical multiple regression analyses were employed to analyze cortisol levels and their association with behavior problems.

Main Results:

• Children with fragile X, especially males, displayed higher salivary cortisol levels compared to controls.
• Significant familial effects on cortisol levels were observed, indicating genetic and environmental influences.
• Elevated cortisol was significantly correlated with behavior problems in children with fragile X, but not in their siblings.

Conclusions:

• The hypothalamic-pituitary-adrenal axis function is independently associated with behavioral problems in children with fragile X syndrome.
• These findings highlight a potential biological marker and therapeutic target for managing behavioral issues in fragile X.