Sadomasochism ( SAY-doh-MASS-ə-kiz-əm) is the giving and receiving of pleasure from acts involving the receipt or infliction of pain or humiliation. Practitioners of sadomasochism may seek sexual pleasure from their acts. While the terms sadist and masochist refer respectively to one who enjoys giving and receiving pain, some practitioners of sadomasochism may switch between activity and passivity.The abbreviation S&M is commonly used for Sadomasochism (or Sadism & Masochism), although the initialisms S-M, SM, or S/M are also used, particularly by practitioners. Sadomasochism is not considered a clinical paraphilia unless such practices lead to clinically significant distress or impairment for a diagnosis. Similarly, sexual sadism within the context of mutual consent, generally known under the heading BDSM, is distinguished from non-consensual acts of sexual violence or aggression. Definition and etymology
The word sadomasochism is a portmanteau of the words sadism () and masochism. The two words incorporated into this compound, "sadism" and "masochism", were originally derived from the names of two authors. The term "sadism" has its origin in the name of the Marquis de Sade (1740–1814), who not only practised sexual sadism, but also wrote novels about these practices, of which the best known is Justine. "Masochism" is named after Leopold von Sacher-Masoch (1836–1895), who wrote novels expressing his masochistic fantasies. These terms were first selected for identifying human behavioural phenomena and for the classification of  psychological illnesses or deviant behaviour.
Angelman syndrome or Angelmans syndrome (AS) is a genetic disorder that mainly affects the nervous system. Symptoms include a small head and a specific facial appearance, severe intellectual disability, developmental disability, limited to no functional speech, balance and movement problems, seizures, and sleep problems. Children usually have a happy personality and have a particular interest in water. The symptoms generally become noticeable by one year of age.Angelman syndrome is due to a lack of function of part of chromosome 15, typically due to a new mutation rather than one inherited from a persons parents. Most of the time, it is due to a deletion or mutation of the UBE3A gene on that chromosome. Occasionally, it is due to inheriting two copies of chromosome 15 from a persons father and none from their mother (paternal uniparental disomy). As the fathers versions are inactivated by a process known as genomic imprinting, no functional version of the gene remains. Diagnosis is based on symptoms and possibly genetic testing.No cure is available. Treatment is generally supportive in nature. Anti-seizure medications are used in those with seizures. Physical therapy and bracing may help with walking. Those affected have a nearly normal life expectancy.AS affects 1 in 12,000 to 20,000 people. Males and females are affected with equal frequency. It is named after British pediatrician Harry Angelman, who first described the syndrome in 1965. An older term, happy puppet syndrome, is generally considered pejorative. Prader–Willi syndrome is a separate condition, caused by a similar loss of the fathers chromosome 15.