Ricerc@Sapienza

The 2017 nosology defines the new criteria for hypermobile Ehlers-Danlos syndrome (hEDS), which is now considered one end of a continuous spectrum encompassing isolated, nonsyndromic joint hypermobility (JH) and hypermobility spectrum disorders (HSDs). Preliminary data indicate a link between JH and neurodevelopmental disorders and, in particular, developmental coordination disorder (DCD) in children. Assessing DCD in adults is difficult and the recently described functional difficulties questionnaire 9 (FDQ-9) is one of the few available tools.

Joint hypermobility (JH) is a common, though largely ignored physical trait with increasing clinical reverberations. A few papers suggest a link between JH and selected neurodevelopmental disorders, such as developmental coordination disorder (DCD). JH is also the hallmark of various hereditary connective tissue disorders (HCTDs). Children with HCTDs may present abnormal neurodevelopment but its manifestations remain undetermined.

The 2017 classification of Ehlers-Danlos syndromes (EDS) identifies three types associated with causative variants in COL1A1/COL1A2 and distinct from osteogenesis imperfecta (OI). Previously, patients have been described with variable features of both disorders, and causative variants in COL1A1/COL1A2; but this phenotype has not been included in the current classification. Here, we expand and re-define this OI/EDS overlap as a missing EDS type. Twenty-one individuals from 13 families were reported, in whom COL1A1/COL1A2 variants were found after a suspicion of EDS.