SPR and dopa-responsive dystonia: The Quinoid Dihydropteridine Reductase NM_000320 (QDPR) c.68G > A mutation and Sepiapterin Reductase NM_003124 (SPR) c.596-2A > G splice variant, are autosomal recessive mutations known to cause dihydropteridine reductase (DHPR) deficiency and Dopa-Responsive Dystonia (DRD) respectively in the Maltese with a high carrier frequency compared to other populations [2].