What builds up in Lesch-Nyhan syndrome?
What builds up in Lesch-Nyhan syndrome?
Lesch-Nyhan syndrome is caused by a mutation or change in a gene. This change results in the absence of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). HPRT is needed to metabolize uric acid. Without this enzyme, uric acid builds up in the central nervous system, kidneys, and other areas of the body.
What tissues are affected by Lesch-Nyhan syndrome?
Lesch-Nyhan syndrome is inherited as an X-linked recessive genetic disorder that, with rare female exceptions, most often affects males. The symptoms of Lesch-Nyhan syndrome include impaired kidney function, acute gouty arthritis, and self-mutilating behaviors such as lip and finger biting and/or head banging.
What type of mutation causes Lesch-Nyhan syndrome?
HPRT1 gene mutations that cause Lesch-Nyhan syndrome result in a severe shortage (deficiency) or complete absence of hypoxanthine phosphoribosyltransferase 1. When this enzyme is lacking, purines are broken down but not recycled, producing abnormally high levels of uric acid.
Why is there megaloblastic anemia in Lesch-Nyhan syndrome?
Lesch Nyhan Disease (LND) is an inherited metabolic disorder caused by deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGprt). This enzyme plays a role in the purine salvage pathway, in which hypoxanthine and guanine are recycled into purine nucleotides.
What causes self mutilation in Lesch-Nyhan syndrome?
Serotonin, also a neurotransmitter, has been shown to be regulated by dopamine release in presynaptic channels, and depletion of serotonin will result in high-frequency stimulation, which is seen in Lesch-Nyhan patients. One of the most striking features of LNS is self-mutilative behavior.
How does Lesch-Nyhan syndrome work?
In Lesch–Nyhan syndrome, the defective gene is that for hypoxanthine-guanine phosphoribosyltransferase (HGPRT), a participant in the ‘recycling’ of purine nucleotides. Female carriers have a second X chromosome, which contains a “normal” copy of HPRT, preventing the disease from developing, though they may have …
How does Lesch-Nyhan cause hyperuricemia?
Extreme nail biting is sometimes caused by Lesch-Nyhan Syndrome. The HGPRT deficiency causes a build-up of uric acid in all body fluids. The combination of increased synthesis and decreased utilization of purines leads to high levels of uric acid production.
What is Smith Magenis Syndrome?
Summary. Smith-Magenis syndrome (SMS) is a complex developmental disorder that affects multiple organ systems of the body. The disorder is characterized by a pattern of abnormalities that are present at birth (congenital) as well as behavioral and cognitive problems.
What is SMS Smith-Magenis syndrome?
What is Lesch Nyhan syndrome?
Lesch Nyhan syndrome is a condition characterized by neurological and behavioral abnormalities and the overproduction of uric acid in the body. It occurs almost exclusively in males. Signs and symptoms may include inflammatory arthritis (gout), kidney stones, bladder stones, and moderate cognitive disability.
What are the behavioral abnormalities of Lesch-Nyhan syndrome?
Additional behavioral abnormalities include aggressiveness, vomiting, and spitting. Self-mutilating behaviors regularly lead to loss of tissue. Children with Lesch-Nyhan syndrome may have difficulty swallowing (dysphagia) and may be difficult to feed.
What tests are used to diagnose Lesch-Nyhan syndrome?
Carrier testing for Lesch-Nyhan syndrome is possible using molecular genetic testing. Prenatal diagnosis and preimplantation genetic diagnosis are possible if the disease-causing HPRT1 gene mutation has been identified in an affected family member.
What are the treatment options for Lesch-Nyhan syndrome?
Children with Lesch-Nyhan syndrome usually require physical restraint at the hips, chest, and elbows so they do not injure themselves. Elbow restraints keep the hands free. Biting of fingers and/or lips, which can lead to permanent disfigurement, may be prevented by the use of a mouth guard (oral prosthetic) or the removal of the teeth.