Case Study

     A family in northern Italy has a horrifying inherited illness in which degeneration of the sleep center of the brain makes some parts of sleep impossible - slow wave sleep and rapid eye movement (REM) sleep. Records from the 19th century allow the pattern of inheritance to be determined. Of 288 relatives over 6 generations, 29 people have had the disorder. There are no carriers, both sexes are affected, and every generation is affected until by chance no one inherits the disease-causing gene. 

     Symptoms begin at the average age of 49 years and include inability to produce tears, skin blotches, inability to feel pain, and poor reflexes as well as the disturbed sleep. The lack of normal sleep eventually causes emotional instability, hallucinations, stupor, coma, and finally death 13 months after symptom onset. Body functions that follow circadian rhythms, such as blood pressure and the levels of some hormones, become abnormal as the sleep/wake cycle is disrupted.

    Fatal Familial Insomnia is caused by a point mutations in codon 178 of the gene for prion protein.