A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a de novo mutation), or it can be inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size).There are well over 6,000 known genetic disorders, and new genetic disorders are constantly being described in medical literature. More than 600 genetic disorders are treatable. Around 1 in 50 people are affected by a known single-gene disorder, while around 1 in 263 are affected by a chromosomal disorder. Around 65% of people have some kind of health problem as a result of congenital genetic mutations. Due to the significantly large number of genetic disorders, approximately 1 in 21 people are affected by a genetic disorder classified as "rare" (usually defined as affecting less than 1 in 2,000 people).
The person is assisted by an anesthesiologist or resident to make a specific surgical position, then sterile drapes are used to cover the surgical site or at least a wide area surrounding the operating field; the drapes are clipped to a pair of poles near the head of the bed to form an "ether screen", which separates the anesthetist/anesthesiologists working area (unsterile) from the surgical site (sterile).Anesthesia is administered to prevent pain from an incision, tissue manipulation and suturing. Depending on the kind of operation, anesthesia may be provided locally or as general anesthesia. Spinal anesthesia may be used when the surgical site is too large or deep for a local block, but general anesthesia may not be desirable. With local and spinal anesthesia, the surgical site is anesthetized, but the person can remain conscious or minimally sedated. In contrast, general anesthesia renders the person unconscious and paralyzed during surgery. The person is intubated and is placed on a mechanical ventilator, and anesthesia is produced by a combination of injected and inhaled agents. Choice of surgical method and anesthetic technique aims to reduce the risk of complications, shorten the time needed for recovery and minimise the surgical stress response. Intraoperative phase
The intraoperative phase begins when the surgery subject is received in the surgical area (such as the operating theater or surgical department), and lasts until the subject is transferred to a recovery area (such as a post-anesthesia care unit).An incision is made to access the surgical site.