B4GALT7 and Ehlers-Danlos syndrome: The EDS spondylodysplastic type (group D: disorders of glycosaminoglycan biosynthesis) is either caused by homozygous or compound heterozygous mutations in the B4GALT7 gene on chromosome 5q35, or by mutations in the B3GALT6 gene (galactosytransferases) (OMIM # 615349) or in the SLC39A13 gene (zinc transporter) (OMIM # 612350) [2, 3].