CCR5-Δ32 polymorphism--a possible protective factor from gait impairment amongst post--stroke patients

Background and purpose: Stroke and small vessel disease cause gait disturbances and falls. The naturally occurring loss- -of--function mutation in the C--C chemokine receptor 5 gene (CCR5--.32) has recently been reported as a protective factor in post--stroke motor and cognitive recovery. We sought to examine whether it also influences gait and balance measures up to 2 years after stroke. Method: Participants were 575 survivors of first--ever, mild--moderate ischaemic stroke or transient ischaemic attack from the TABASCO prospective study, who underwent a 3 T magnetic resonance imaging at baseline and were examined by a multi--professional team 6, 12 and 24 months after the event, using neurological, neuropsychological and mobility examinations. Gait rhythm and the timing of the gait cycle were measured by force-sensitive insoles. CCR5--.32 status and gait measures were available for 335 patients. Results: CCR5--.32 carriers (16.4%) had higher gait speed and decreased (better) stride and swing time variability 6 and 12 months after the index event compared to non-carriers (p < 0.01 for all). The association remained significant after adjustment for age, gender, education, ethnicity and stroke severity. Conclusions: Significant associations were found between gait measurements and CCR5--.32 loss--of--function mutation amongst stroke survivors. This is the first study showing that genetic predisposition may predict long--term gait function after ischaemic stroke.