Familial Advanced Sleep Phase Disorder (FASPD) is a rare genetic sleep disorder characterized by a consistently earlier-than-normal sleep-wake cycle. Individuals with FASPD typically experience an advanced sleep phase, meaning they go to bed and wake up several hours earlier than the typical sleep-wake pattern.
Familial advanced sleep phase disorder genetic testing is included in Diagnostiki Athinon Monogenic Diseases Genetic Testing along with approximetaly 100 other inherited diseases, including cystic fibrosis (71 mutations) and hereditary breast cancer (genes BRCA1 415 mutations & BRCA2 419 mutations).
Key features of Familial Advanced Sleep Phase Disorder include:
- Early Sleep Onset: Individuals with FASPD naturally tend to fall asleep much earlier in the evening than the general population.
- Early Wake Time: They also wake up unusually early in the morning.
- Consistent Pattern: The early sleep-wake pattern persists consistently, and attempts to delay bedtime often result in early awakening rather than a longer sleep duration.
- Normal Sleep Architecture: Despite the advanced sleep phase, the quality and architecture of sleep are typically normal.
- Genetic Basis: FASPD has a genetic component and tends to run in families. Specific gene mutations associated with FASPD have been identified.
- Impact on Daily Functioning: The advanced sleep-wake cycle can affect an individual's daily functioning, especially if their schedule conflicts with societal norms.
While FASPD is relatively rare, it can have a significant impact on an individual's lifestyle and relationships. The genetic basis of FASPD has been linked to mutations in certain genes, including PER2 and CSNK1D, which regulate the body's internal circadian clock.
Familial Advanced Sleep Phase Disorder management involves strategies to adapt to the early sleep-wake cycle, improve sleep hygiene, and maintain a consistent schedule. Bright light exposure in the evening and melatonin supplementation may be used under the guidance of a healthcare professional to help adjust the circadian rhythm.
If FASPD significantly impairs an individual's daily functioning, consultation with a sleep specialist or healthcare professional specializing in sleep disorders may be beneficial. Additionally, genetic counseling may be considered, especially for individuals with a family history of FASPD, to understand the inheritance pattern and potential genetic testing options.
It's important to note that FASPD is distinct from other sleep disorders, such as insomnia or circadian rhythm sleep disorders, and its diagnosis should be made based on a thorough evaluation by healthcare professionals with expertise in sleep medicine.
The variant c.130A>G (p.Thr44Ala) is present in the CSNK1D gene, which encodes for the delta isoform of casein kinase, which regulates circadian rhythm. A single copy of the mutation confers susceptibility to the individual to suffer from the disease, so its inheritance pattern is considered autosomal dominant.
Another mutation associated with this condition is c.1984A>G (p.Ser662Gly), located in the PER2 gene, which codes for a protein of the same name that regulates circadian rhythm. As mentioned above, its inheritance pattern is autosomal dominant with high penetrance.
The Familial Advanced Sleep Phase Disorder genetic test analyzes the most frequent pathogenic mutation of the CSNK1D gene.
With the technique used for genetic testing, only the gene's specific mutations, which are the most important and frequent in the literature, are analyzed. However, it should be noted that there are likely other gene or chromosomal mutations in the gene to be tested, which cannot be identified with this method. Different analysis techniques can be used for these cases, such as e.g. next-generation sequencing (NGS).
