What is Lesch – Nyhan Syndrome?

Lesch-Nyhan Syndrome (LNS) is a rare genetic condition that occurs almost exclusively in males. It is inherited as an X linked recessive gene and causes a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT).  Without this enzyme, people with LNS build up abnormally high levels of uric acid build in their bodies. Excess uric acid levels can cause individuals to develop gout-like swelling in their joints and in some cases, cause kidney and bladder stones. LNS is also characterised by neurological and behavioural abnormalities.

What are the Symptoms of Lesch – Nyhan Syndrome?

One of the first symptoms of Lesch -Nyhan Syndrome that may be seen is orange sand like deposits in a child’s diaper (uric acid crystals) which may occur in children as young as 3 months. Other symptoms of LNS include:

• Weak muscle tone (difficulty holding up the head or sitting)
• Uncontrollable, abnormal muscle movements (flexing, jerking, flinging or flailing)
• Pain and swelling of the joints
• Muscle stiffness
• An inability to crawl, stand or walk
• Difficulty swallowing (dysphagia)
• Impaired kidney functioning
• Kidney and bladder stones
• Blood in the urine
• Persistent and compulsive self-injurious behavior (biting the fingers, hands, lips, and cheeks; banging the head or limbs)

Lesch-Nyhan variants

Patients with a less severe variant of the disease and partial syndromes are becoming increasingly recognized. In these milder variants, self-injury may not occur, cognition may be normal, and the abnormal muscle tone of patients that results in muscular spasms and abnormal posture may be mild or even absent. Some may have overproduction of uric acid and its consequences alone.