The authors report two brothers who presented with motor delay and stiffness. The elder boy had auto-mutilation of lips and fingers. Serum uric acid was elevated in both the children. Both the boys had undetectable hypoxanthine-guanine phosphoribosyl transferase activity in hemolysate, confirming the diagnosis of Lesch-Nyhan syndrome. Molecular genetic testing revealed a new mutation in the HPRT1 gene.