Lesch-Nyhan syndrome is an X-linked disorder of purine metabolism. A man with this condition lacks an enzyme called transferase. It is a rare disease characterized by a combination of neurological abnormalities, behavioral disorders and high levels of uric acid in the body.
Lesch-Nyhan syndromeisgenetic diseasewhich is active from birthand lasts a lifetime. Lesch-Nyhan syndrome (LNS, hypoxanthine-guanine phosphoribosyl transferase (HPRT) deficiency) is a rare disease, affecting one person in 380,000 live births. It has three main features:
- neurological dysfunction
- cognitive impairment
- behavior deviation
Additionally, there is also gout.
Lesch-Nyhan syndrome - symptoms
The first symptoms that can be noticed in infancy, between 3 and 6 months of age, are decreased muscle tone (hypotonia) and developmental delay.
Increased levels of uric acid in the blood and its increased excretion with urine can lead to acute renal failure and even death.
In addition, uric acid crystals may appear in the diaper of a baby with Lesch-Nyhan syndrome. In addition, in patients with Lesch-Nyhan syndrome, characteristic disorders related to various systems as well as behavioral disorders are observed.
Nervous system disorders appear before the age of 12. Usually these are:
- dystonias - involuntary movements causing the body to twist and flex
- chorea - pointless repetitive movements of e.g. fingers, arms, facial grimaces
- ballism - making sweeping, sudden movements of the limbs, movements similar to heavy chorea
- weakening (hypotonia) of muscle tension
- hypertonia, spasticity and hyperreflexia (exorbitant deep reflexes)
- motor development delay - lack / delay in crawling, sitting down, walking
- dysarthria - speech impairment
- dysphagia - swallowing disorders, feeding and eating problems
- opisthotonus - arched body curve(head and heels bent backwards)
- intellectual disability - usually of moderate degree, in some people normal cognitive functions are preserved
- physical disability
Behavioral disorders in Lesch-Nyhan syndrome affect 85 percent of patients and are the most common:
- biting (fingers, lips, inside cheeks)
- head banging
- scratching face
- aggression, tendency to be irritated
- vomiting
- screams
- spitting
In addition, joint, skin and urinary disorders are observed:
- deposition of sodium urate crystals: in the joints (gout attacks), in the cartilage of the joints and ears (tophus), formation of kidney stones already in infancy
- scoliosis, fractures, hip dislocation, joint contractures
- excretion of excess uric acid in the form of sodium urate
- hematuria due to irritation of the urinary system by stones
- frequent urinary tract infections due to kidney stones
- impaired kidney function and threat of kidney failure
Patients with Lesch-Nyhan syndrome tend to self-injure, causing severe inflammation of the mucosa and periodontium, resulting in tooth loss. They also suffer from underweight, reduced immunity and megaloblastic anemia.
Lesch-Nyhan syndrome: treatment
Since Lesch-Nyhan syndrome is incurable, treatment focuses on relieving symptoms. The most important thing in treatment is to reduce the amount of uric acid in the blood to avoid its crystals being deposited in various parts of the body. Kidney stones are broken down by extracorporeal lithotripsy. A low-purine diet is also recommended.
However, there is no cure for mental and neurological disorders. The patient should be helped by preventing self-harm - psychotherapy, pharmacological agents and even direct coercion are used. Sometimes teeth must be extracted.
Currently, men with Lesch-Nyhan syndrome live up to 3-4. decades of life. The main cause of death is aspiration pneumonia and complications of chronic nephrolithiasis. There are also cases of sudden death for no apparent reason.