Thus, it has been suggested that free radicals, oxidative stress, and reactive oxygen species may play some role in the neuropathology of LNS.However, some evidence suggests against a role for uric acid in the neuropathology of Lesch–Nyhan syndrome:

Hyperuricemia associated with classic primary gout, which is caused by low uric acid renal clearance rather than uric acid overproduction, is not associated with neuropathology. Hypouricemia occurs in a number of purine disorders, in particular xanthinuria. Despite having complete absence of blood uric acid, xanthinuria patients do not have any neuropathology, nor any other disease states – other than the kidney stones caused by accumulation of insoluble xanthine in lieu of uric acid.Similarly,  uric acid does not penetrate the blood–brain barrier well. However, oxidative stress due to uric acid is now thought to figure in metabolic syndrome, atherosclerosis, and stroke, all syndromes associated with high uric acid levels. Similarly, Superoxide dismutase ( "SOD" ) and SOD-mimetics such as TEMPOL ameliorate the effects of hyperuricemia. Likewise, 6-hydroxydopamine (the putative animal model for Lesch–Nyhans neuropathy) apparently acts as a neurotoxin by generation of reactive oxygen species. It may be that oxidative stress induced by some other oxypurine such as xanthine causes the disease. Diagnosis
When an affected individual has fully developed the three clinical elements of uric acid overproduction, neurologic dysfunction, and cognitive and behavioral disturbances, diagnosis of LNS is easily made. Diagnosis is less easy in the early stages, when the three features are not yet obvious.
Ashley and Ashil Fokeer, born on November 2, 1992, in Mauritius
Joseph and Luka Banda (born January 23, 1997, in Zambia), separated in 1997 in South Africa by Ben Carson (with a later intervention in 2001 to artificially close their skulls). Craniopagus. José Armando and José Luis Cevallos Herrera were born in September 1999 in Milagro, Ecuador. They were accepted in 2021 to the State University of Milagro. Maria del Carmen Andrade Solis and Maria Guadalupe Andrade Solis (better known as Carmen and Lupita) were born in June 2000 in Veracruz, Mexico. They later moved to the United States for healthcare with their parents. Born 21st century
Carl and Clarence Aguirre, born with vertical craniopagus in Silay City, Negros Occidental, on April 21, 2002. They were successfully separated on August 4, 2004. Tabea and Lea Block, from Lemgo, Germany, were born as craniopagus twins joined on the tops of their heads on August 9, 2003. The girls shared some major veins, but their brains were separate. They were separated on September 16, 2004, although Tabea died about 90 minutes later. Sohna and Mohna from Amritsar, India. Born in New Delhi on June 14, 2003. They have two hearts, arms, kidneys and spinal cords while share liver, gall bladder and legs. Anastasia and Tatiana Dogaru, born outside Rome in Lazio, Italy, on January 13, 2004. As craniopagus twins, the top of Tatianas head is attached to the back of Anastasias head.