Others are linked to dystonia and central nervous system disorders (SPRE), deafness or hearing loss (COX1, SMPX, PRPS1, CAH2, ACY1), encephalopathy (CMC1, VATA, ACY1), various neuro- or neuronopathies (COX1, CATD, HXK1), structural central nervous system anomalies or lesions, partly with visual impairment (COX1, HXK1, PRPS1, ACY1) as well as connective tissue disorders (CO5A1, VATA) (see OMIM number for further, itemized reference). The gene discussed is SMPX; the disease is Visual impairment.