Rare Cases of PLOD1-Related Kyphoscoliotic Ehlers-Danlos Syndrome in a Korean Family Identified by Next Generation Sequencing

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is an autosomal recessive connective tissue disorder characterized by muscular hypotonia, hyperextensible skin, skin fragility, joint hypermobility, and progressive kyphoscoliosis. The disorder results from a deficiency of the enzyme collagen lysyl hydroxylase 1 due to mutations in the gene PLOD1. We describe the rare cases of kEDS in Korean siblings with two novel compound heterozygous variants, c.926_934del (p.Leu309_Leu311del) and c.2170_2172del (p.Phe724del) in the PLOD1 gene. They had congenital hypotonia, joint laxity, skin hyperextensibility, Marfanoid habitus, high myopia and atrophic scarring. The younger sibling had an early-onset progressive kyphoscoliosis, while the older sibling showed mild scoliosis during childhood. Intrafamilial variability of the clinical severity and age of kyphoscoliosis onset observed in our cases.