Lesch Nyhan syndrome

Preyalence and causes

This X-linked recessive condition, which almost exclusively affects boys, was first described in 1964 by William Nyhan. (24) Although often described as a rare condition, the incidence rate quoted for this condition varies widely between 1 in 10 000 and 1 in 380 000 live births. The usual mode of inheritance is from a carrier mother to her affected son. The syndrome is caused by an inborn error of purine metabolism, resulting in an abnormally high level of xanthine and uric acid in the blood of the affected person. A deficient production of hypoxanthine phosphoriposyl transferase is responsible for the abnormality in purine metabolism. The gene locus for hypoxanthine phosphoriposyl transferase has recently been identified in the short arm of chromosome Xq26-27.

Clinical features

Infants with Lesch-Nyhan syndrome develop attacks of hypertonia within a few weeks of birth. They soon develop spasticity along with other motor disabilities in the form of ataxia and involuntary movements such as choreoathetosis. Most affected children have severe mental retardation, become wheelchair bound, and show increased tendon reflexes. Microcephaly is common and approximately half of the children develop epileptic seizures. The overall prognosis for this condition remains poor and most affected subjects die in early adulthood.

Behayioural symptoms

Most children affected by Lesch-Nyhan syndrome show verbal and physical aggression. However, more characteristic problems, which are resistant to management, are self-injurious behaviours which affect over 85 per cent of these children. (25) Most prominent self-injurious behaviours include biting of lips, the inside of the mouth, and fingers.(9) Other common self-injurious behaviours include thumping of ears and face, and hitting the head against objects. Although in some cases these behaviours start in adolescence, in the majority of cases they start between the ages of 2 and 3% years. It is reported in some cases that self-injurious behaviours reduce in frequency and severity after age 10. Sometimes there is an episodic nature to the self-injurious behaviours with a relatively problem-free period for a few weeks in between periods of intense self-injurious behaviours each lasting for a few weeks. It appears that self-injurious behaviours are not totally under the control of the affected individuals and many children try to avoid these behaviours yet are unable to do so. (4) Various explanations of these self-injurious behaviours such as malformation in the innervation of muscles, hyperexcitability of motor neurones, and abnormalities in the basal ganglia D 1-receptor system (D. receptors are rich in hypoxanthine phosphoriposyl transferase) have been offered, yet none has been proven unequivocally.

Break Free From Passive Aggression

Break Free From Passive Aggression

This guide is meant to be of use for anyone who is keen on developing a better understanding of PAB, to help/support concerned people to discover various methods for helping others, also, to serve passive aggressive people as a tool for self-help.

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