QPRT and early-onset autosomal dominant Alzheimer disease: QPRT plays a prominent role inQA homeostasis in the brain, therefore, malfunction of QPRT increases QA levels, whichis strongly involved in a series of severe neurodegenerative disorders includingHuntington’s disease, Alzheimer’s disease, Epilepsia and AIDSdementia complex11, 12, 13, 14, 15, 16, 17, 18.