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20 Diseases You've Probably Never Heard Of


4
Lesch Nyhan Syndrome
This syndrome can cause finger biting.
This syndrome can cause finger biting.
iStockphoto/Thinkstock

This disease is caused by the absence or deficiency of an enzyme. Symptoms include impaired kidney function, joint pain and self-mutilating behaviors such as lip and finger biting and/or head-banging. Additional symptoms may include muscle weakness (hypotonia), uncontrolled muscle movements and neurological impairment. Other names for it include HGPRT or HPRT deficiency, or hypoxanthine-guanine phosphoribosyl transferase deficiency.

Read More About the Disease From NORD


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