Clinical and instrumental phenotyping of gait in subjects with Cri du Chat syndrome

Background Cri du Chat syndrome (CdCS) is a rare genetic disorder characterized by disabling psychomotor and gait impairments. The aim of this study is to assess and characterize CdCS gait through a comprehensive and validated set of trunk acceleration-derived gait indexes by means of inertial gait analysis. Methods In this cross-sectional study, we enrolled 38 CdCS individuals (age 22.6 [18.4–26.0] years, 52.6% females) and 39 healthy subjects (HS) matched for age, sex and speed of gait. Besides the conventional spatio-temporal parameters we calculated: the harmonic ratio (HR, primary outcome), the largest Lyapunov exponent for short time-series (sLLE), the percent determinism in recurrence quantification analysis (RQA). Results Compared to HS, CdCS gait was characterized by lower HR (CdCS: 1.6 [1.4–1.7] vs. HS: 2.6 [2.4–2.7], p = 0.001), lower RQA ( p = 0.001) and higher sLLE ( p = 0.001). In CdCS individuals, we also found a higher stride time, along with a lower cadence and range of pelvic obliquity during gait ( p < 0.025 for all comparisons). Logistic regression analysis identified HR and RQA in the antero-posterior plane and the range of pelvic obliquity as the independent and most relevant features able to differentiate gait of CdCS subjects from HS. Conclusions Our study provides a comprehensive description of CdCS gait pattern, predominantly characterized by reduced symmetry, rhythmicity, and stability. Trial registration : The study protocol was approved by local Ethical Committee (CE Pavia, Approval Number: 2022-3.11/797) and pre-registered on www.clinicaltrials.gov (NCT05887739).