What is Lesch-Nyhan Syndrome?
Lesch-Nyhan syndrome (LNS) or Kelley-Seegmiller syndrome is
a rare hereditary disorder that affects the body’s ability to
breakdown and build Purines.
A purine (Adenine, Guanine) is a protein found in normal healthy
body tissue that makes the body’s blueprint. They are also
important for the metabolism of RNA and DNA that make up our
genetic code, this mutation causes uric acid build up, neurological
disability, and self injury.
What is the cause/Pathophysiology?
Lesch-Nyhan is caused by a mutation in the HPRT1
gene, a x-linked recessive disorder, making it a sex-linked
Who is it most common in?
LNS occurs in similar frequency in all races, but
more common in males. 1 in 380,000 people are
infected by LNS. If females are diagnosed LNS
usually presents as asymptomatic, but if not the only
symptom is severe gout.
What parts of the body does it effect?
● Body tissue
● Nervous System
● Bodily harm is a common
symptom with LNS
causing injury to various
parts of the body
What are the symptoms?
Symptoms of LNS are...
● Nervous System impairment
● Chorea: jerking motions
● Hyperuricaemia: blood in urine
● Pain and swelling in joints
● Difficulty swallowing
● Behavioral problems
● Balance problems
● Delay in motor development
● Hypertonia: too much muscle tone
● Renal failure: kidney failure
● Puberty is delayed
● Testicular Atrophy: testes shrink
● Uric acid overproduction
● Ballismus: flailing of limbs
● Kidney/Bladder stones
● Growth is delayed
● Learning disabilities
● Manipulative behavior
● Dystoma: tensing of muscles
● Spastic Cerebral Palsy: contraction
What are the onset of symptoms?
Most symptoms of LNS are congenital, but some
aren’t present at birth. As the individual get older
the symptoms are more severe. In infancy stages (3-
12 months) patients usually experience delayed
motor function, and 6-18 months patients
experience chorea and involuntary movements
within their body.
What are the exams/tests?
Physicians can diagnose LNS by physical examination, spot tests,
and genetic testing. In physical examination, a doctor looks for
certain symptoms common for the disease, but can lead to a
misdiagnosis of cerebral palsy, mental retardation, or other
metabolic disorders. In a spot test doctors look for high uric acid
in blood and urine to help diagnose LNS, but results can lead to
other metabolic disorders. Lastly physicians can perform
molecular genetic mutation test on the HPRT gene to physically
see the mutation, to lead to an 100% diagnosis.
What is the treatment?
There are no FDA approved drugs to treat LNS, but
there are drugs in the clinical stage of testing. Doctors
and researchers have broken down the disease into it’s
major symptoms and treat symptomatically, with
drugs and support within the family.
What is the prognosis?
When a patient has LNS, death is usual in the 20s or
30s with few reaching their 40th birthday. Death is
usually from aspiration pneumonia or complications
of nephrolithiasis, sometimes sudden death is