Genetic Disease: Lesch-Nyhan Syndrome

LESCH NYHAN SYNDROME

A report by
Precious Yashim Diane 148181
Student of molecular biology and genetics department, Faculty of arts and science, Eastern Mediterranean University

Introduction
Lesch-Nyhan syndrome also known as HPRT (Hypoxanthine Phosphoribosyltransferase 1) deficiency or Kelley Seegmiller Syndrome is a rare hereditary disease which affects young boys, usually causing early death. It is marked by compulsive self-mutilation of the head and hands, together with learning difficulties and involuntary muscular movements. Lesch Nyhan syndrome corresponds with virtually complete HPRT deficiency and was described by Michael Lesch and William Nyhan in 1964. (1)
The disease was first discovered by William Nyhan and Michael Lesch in the

Patients are usually normal at birth but one of the earliest signs of the disease may be the observation of orange crystals in the diapers or crystalluria with obstruction of the urinary tracts. Other uncommon forms of presentation include renal failure or acidosis with repeated vomiting. The effect of psychomotor delay starts to become evident within three to six months. A delay in the acquisition of sitting and head support may lead to neurological consultation. Self-mutilation in the form of lip biting or finger chewing, biting of the tongue and biting of the lips can appear as soon as teeth are present. Head banging are usually also associated with the disease. And these mutilations can cause serious injuries or scars to the body. However the compulsive self-injury is seen in about eighty five percent of affected males. Approximately one in every 380,000 live births are affected by lesch Nyhan syndrome and only male children mostly get affected. Although, it is very rare, there have been few cases in which girls who have the disorder have been reported. Women who are carriers of the disease do not have any of the symptoms but sometimes on occasions develop inflammation of the joints (gout) at an advanced age or old age.

For lesch Nyhan syndrome, there are two stages or phases related with severity of this disease. These are:
I. The classic lesch Nyhan syndrome: this is the most severe or chronic form of this disease, the classic aspect self-mutilation and behavioral problems are observed.
II. The variant lesch Nyhan syndrome: this stage does not involve human behavioral problems or self-mutilation. It is the less severe stage of the syndrome.
There is no permanent cure for the neurological defects or crippling symptoms. Allopurinol is a drug that is usually prescribed to lower the risk of gout and can be prescribed to patients with lesch Nyhan syndrome because it can also reduce the level of uric acid in the patient. But it is also possible to improve the quality of life considerably for a boy with the disease. The main goal in combatting the disease is the control of the uric acid levels and keeping it within normal range.
This control of the uric acids needs two specific components:
I. Inhibiting the metabolism of hypoxanthine and xanthine to uric acid with allopurinol.
II. Generous hydration at all times. It should be increased during periods of increased fluid