Delineation of musculocontractural Ehlers–Danlos Syndrome caused by dermatan sulfate epimerase deficiency

BACKGROUND: Musculocontractural Ehlers-Danlos Syndrome (mcEDS) is a rare connective tissue disorder caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE (mcEDS-DSE), both of which result in defective dermatan sulfate biosynthesis. Forty-one patients with mcEDS-CHST14 and three patients with mcEDS-DSE have been described in the literature. METHODS: Clinical, molecular, and glycobiological findings in three additional patients with mcEDS-DSE were investigated. RESULTS: Three patients from two families shared craniofacial characteristics (hypertelorism, blue sclera, midfacial hypoplasia), skeletal features (pectus and spinal deformities, characteristic finger shapes, progressive talipes deformities), skin features (fine or acrogeria-like palmar creases), and ocular refractive errors. Homozygous pathogenic variants in DSE were found: c.960T>A/p.Tyr320* in patient 1 and c.996dupT/p.Val333Cysfs*4 in patients 2 and 3. No dermatan sulfate was detected in the urine sample from patient 1, suggesting a complete depletion of DS. CONCLUSION: McEDS-DSE is a congenital multisystem disorder with progressive symptoms involving craniofacial, skeletal, cutaneous, and cardiovascular systems, similar to the symptoms of mcEDS-CHST14. However, the burden of symptoms seems lower in patients with mcEDS-DSE.