Dermatosparaxis Ehlers-Danlos Syndrome · dEDS

Description

Dermatosparaxis Ehlers-Danlos Syndrome (dEDS) is an autosomal recessive connective tissue disorder caused by biallelic loss-of-function variants in ADAMTS2, which encodes procollagen I N-proteinase. The enzyme cleaves the N-terminal propeptide from type I procollagen during fibril assembly, and its absence leaves pN-collagen incorporated into dermal and other matrices. The biochemical step that fails in dEDS is the same step that fails in arthrochalasia EDS, with the enzyme defective in dEDS and the substrate defective in aEDS. The condition has a long veterinary precedent in cattle and sheep, where the term dermatosparaxis was first applied to describe extreme skin fragility before the human disorder was characterized.

Clinical features in humans include severe skin fragility with tearing under minor trauma, sagging redundant skin with a cutis-laxa-like appearance, characteristic craniofacial features in infancy including puffy eyelids, blue sclerae, micrognathia, and gingival hyperplasia, severe bruising, umbilical hernia, and short stature. Visceral and obstetric complications including bladder rupture and premature rupture of membranes have been reported in a subset of cases. Fewer than 30 affected individuals have been described in the medical literature, which places dEDS among the ultra-rare entries in the EDS taxonomy.

The 2017 international classification by Malfait and colleagues in the American Journal of Medical Genetics Part C lists major criteria including extreme skin fragility with congenital or postnatal skin tears, characteristic craniofacial features, redundant or sagging skin including excessive skin folds at the wrists and ankles, increased palmar wrinkling, severe bruising with risk of subcutaneous hematomas, umbilical hernia, postnatal growth restriction, and short limbs and short stature. Minor criteria include soft doughy skin, skin hyperextensibility, atrophic scars, generalized joint hypermobility, complications of visceral fragility, perinatal complications related to connective tissue fragility, and delayed motor development. Diagnosis requires extreme skin fragility and characteristic craniofacial features plus additional major or minor criteria, with confirmatory testing. Confirmatory testing is biallelic pathogenic ADAMTS2 variants on multigene panel or exome, supported by biochemical demonstration of pN-collagen accumulation in dermal fibroblast culture.

Treatments to date

Management is supportive. No approved therapy targets the enzyme defect, and no clinical trial program is active.

Skin protection is the central daily management problem. Padding of bony prominences, careful handling in infancy, and wound care that anticipates poor tensile strength reduce injury frequency and complication. Suture closure uses techniques adapted to fragile tissue, and adhesive selection follows EDS dermatology guidance to limit secondary tearing on removal. Hernia repair, when needed, is performed by surgeons familiar with connective tissue disorders.

Growth and development are followed through pediatric care with attention to feeding in infancy when craniofacial features affect oral function, and to motor milestones given hypotonia and joint laxity in some cases. Physical therapy supports postural control without forcing extreme joint range.

Visceral surveillance is informed by the rare reports of bladder rupture and other internal complications, with imaging and surgical planning tailored to symptoms rather than scheduled at population intervals given the small evidence base. Pregnancy management uses maternal-fetal medicine input given premature rupture of membranes risk and connective tissue considerations at delivery. Genetic counseling addresses the 25 percent recurrence risk in future pregnancies of carrier parents and the value of cascade testing in extended families with consanguinity.

No registry-scale natural history study has been completed for dEDS, and published evidence remains at the case-series level.