Among the DMP-associated genes, three have been previously implicated in neurodegenerative or neurodevelopmental disorders: ARSB, encoding for the Arylsulfatase B, has been associated with Alzheimer’s disease and Parkinson’s disease;11,12MGRN1, encoding Mahogunin Ring Finger 1, has been implicated in late-onset spongiform neurodegeneration;13 and IQSEC1, encoding for the IQ Motif And Sec7 Domain ArfGEF 1, has been associated with a neurodevelopmental disorder14. The gene discussed is IQSEC1; the disease is Parkinson disease.