The region contains few genes, but D6S1009 is within 100 kb of the peroxisome biogenesis factor 7 (PEX7) gene, mutations in which can cause ocular phenotypes as part of the severe systemic syndromes Refsum disease [60,61] and rhizomelic chondrodysplasia punctata [60,62]. Here, PEX7 is linked to rhizomelic chondrodysplasia punctata.