Melatonin profiles and sleep characteristics in boys with fragile X syndrome: A preliminary study

Abstract

Sleep patterns and endogenous melatonin profiles in 13 fragile X boys between the age of 4.7 and 11.0 years were compared to those of 8 age-matched, normal control boys. Parents recorded sleep patterns on a Sleep Diary Chart for 14 consecutive days. Twelve saliva samples were obtained from 8 fragile X participants and all of the controls over 48 hours for the assessment of salivary melatonin profiles. The results showed greater variability in total sleep time and difficulty in sleep maintenance in fragile X boys compared with the control participants. Nocturnal melatonin production, expressed as both peak level and area under the concentration-time curve between 20:00 h and 08:00 h, were found to be significantly larger in fragile X boys than in controls. Additionally, the mean of the minimum daytime melatonin levels recorded was significantly higher for the fragile X group. Elevated levels in some fragile X boys relative to the range seen in controls, occurring either during the day or at night, or in both segments of the secretory profile for some individuals, may be due in part to overactivity of the sympathetic nervous system. Alternative molecular mechanisms leading to changes in melatonin profiles in fragile X are also discussed.

A descriptive analysis of sleep behaviour in children with Fragile X

“…Similar to Gould et al (2000), a relatively long average sleep latency was found for the FraX group. This was in contrast to the findings of Elia et al (2000).…”

“…However, the nature of sleep problems in children with FraX, as perceived by their parents, has not been reported, but the limited available literature suggests that sleep problems are an issue. For example, sleep maintenance difficulties were reported in 13 boys with FraX (Gould et al, 2000). The group also showed abnormal melatonin profiles.…”

Intraindividual variability of sleep/wake patterns in relation to child and adolescent functioning: A systematic review

“…One study found greater duration IIV, onset IIV, and duration IIV in boys with fragile X syndrome compared to control children [76]. …”

Melatonin: Pharmacology, Functions and Therapeutic Benefits

“…It is noteworthy that sleep problems are not specific of autism and are also observed in children with intellectual disability associated or not with autism [128]. However, melatonin measures in children with intellectual disability not associated with autism, such as some children with Down syndrome and Fragile X syndrome, showed respectively normal melatonin production despite delayed nocturnal melatonin peak secretion and increased levels of melatonin [130, 131], whereas decreased nocturnal melatonin secretion was mostly observed in children with autism [128]. We reported in two different large samples of children with autism significant relationships between decreased nocturnal urinary excretion and severity of autistic impairments in social communication [127, 132].…”