Rare disease in the context of "Patisiran"

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 chromosome 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). Most genetic disorders are rare in themselves.

Copenhagen disease, sometimes known as Copenhagen syndrome or progressive non-infectious anterior vertebral fusion (PAVF), is a very rare childhood spinal disorder of unknown cause, with distinctive radiological features. It is characterized by the progressive fusion of the anterior vertebral body in the thoracolumbar region of the spine.

It was first identified in 1949 and 80–100 reported cases since, 60% of which were female. Due to the disease's rarity, research into this condition has been limited.

Von Hippel–Lindau disease (VHL), also known as Von Hippel–Lindau syndrome, is a rare genetic disorder with multisystem involvement. It is characterized by polycystic disease and benign tumors with potential for subsequent malignant transformation. It is a type of phakomatosis that results from a mutation in the Von Hippel–Lindau tumor suppressor gene on chromosome 3p25.3.

Neonatal diabetes mellitus (NDM) is a disease that affects an infant and their body's ability to produce or use insulin. NDM is a kind of diabetes that is monogenic (regulated by a single gene) and arises in the first 6 months of life. Infants do not produce enough insulin, leading to an increase in glucose accumulation. It is a rare disease, occurring in only one in 100,000 to 500,000 live births. NDM can be mistaken for the much more common type 1 diabetes, but type 1 diabetes usually occurs later than the first 6 months of life. There are two types of NDM: permanent neonatal diabetes mellitus (PNDM), a lifelong condition, and transient neonatal diabetes mellitus (TNDM), a form of diabetes that disappears during the infant stage but may reappear later in life.

Specific genes that can cause NDM have been identified. The onset of NDM can be caused by abnormal pancreatic development, beta cell dysfunction or accelerated beta cell dysfunction. Along with maturity-onset diabetes of the young (MODY), NDM is a form of monogenic diabetes. Individuals with monogenic diabetes can pass it on to their children or future generations. Each gene associated with NDM has a different inheritance pattern.