answer:Histiocytosis-lymphadenopathy plus syndrome is caused by mutations in the SLC29A3 gene, which provides instructions for making a protein called equilibrative nucleoside transporter 3 (ENT3). ENT3 belongs to a family of proteins that transport molecules called nucleosides in cells. With chemical modification, nucleosides become the building blocks of DNA, its chemical cousin RNA, and molecules such as ATP and GTP, which serve as energy sources in the cell. Molecules derived from nucleosides play an important role in many functions throughout the body. ENT3 is found in cellular structures called lysosomes, which break down large molecules into smaller ones that can be reused by cells. Researchers believe that this protein transports nucleosides generated by the breakdown of DNA and RNA out of lysosomes into the cell so they can be reused. The protein is also thought to transport nucleosides into structures called mitochondria, which are the energy-producing centers of cells. In mitochondria, nucleosides are likely used in the formation or repair of DNA found in these structures, known as mitochondrial DNA. The SLC29A3 gene mutations involved in histiocytosis-lymphadenopathy plus syndrome reduce or eliminate the activity of the ENT3 protein. Researchers speculate that the resulting impairment of nucleoside transport leads to a buildup of nucleosides in lysosomes, which may be damaging to cell function. A lack of ENT3 activity may also lead to a reduction in the amount of nucleosides in mitochondria. This nucleoside shortage could impair cellular energy production, which would impact many body systems. It is unclear how the mutations lead to histiocytosis and other features of the condition or why affected individuals can have different patterns of signs and symptoms.

answer:This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

answer:These resources address the diagnosis or management of histiocytosis-lymphadenopathy plus syndrome: - Genetic Testing Registry: Histiocytosis-lymphadenopathy plus syndrome These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care

answer:Distal myopathy 2 is a condition characterized by weakness of specific muscles that begins in adulthood. It is a form of muscular dystrophy that specifically involves muscles in the throat, lower legs, and forearms. Muscles farther from the center of the body, like the muscles of the lower legs and forearms, are known as distal muscles. Muscle weakness in the ankles is usually the first symptom of distal myopathy 2. The weakness can also affect muscles in the hands, wrists, and shoulders. At first, the muscle weakness may be on only one side of the body, but both sides are eventually involved. This muscle weakness can slowly worsen and make actions like walking and lifting the fingers difficult. Another characteristic feature of distal myopathy 2 is weakness of the vocal cords and throat. This weakness initially causes the voice to sound weak or breathy (hypophonic). Eventually, the voice becomes gurgling, hoarse, and nasal. The weakness can also cause difficulty swallowing (dysphagia).