Abstract
OBJECTIVE: To characterize natural history of Laminin-α2 related muscular dystrophies (LAMA2-RD) to help anticipating complications and identifying reliable outcome measures for clinical trial design and powering. METHODS: We conducted a retrospective, single-center, cross-sectional and longitudinal study on 46 LAMA2-RD pediatric patients (37 families). Patients were seen at the Dubowitz Neuromuscular Centre, London between 1985 and 2019. Data were collected by case note reviews. Time-to-event analysis was performed to estimate median age at complications occurrence. RESULTS: Forty two patients had complete deficiency of Laminin-α2 (CD) and four had partial deficiency (PD). Median age at first and last assessment was 2 years and 12.1 years, respectively. Median follow-up length was 7.8 years (range 0-18 years). Seven CD patients died at median age 12 years. One CD and two PD subjects achieved independent ambulation. We observed a linear increase in elbow flexor contractures in CD subjects. Thirty-two CD and one PD patient developed scoliosis, nine underwent spinal surgery. Twenty-two CD required nocturnal noninvasive ventilation (median age 11.7 years). CD subjects showed a 2.9% linear annual decline in forced vital capacity % predicted. Nineteen CD and one PD patient required gastrostomy insertion for failure to thrive and/or unsafe swallow (median age 10.9 years). Four CD patients had partial seizures. Mild left cardiac ventricular dysfunction and rhythm disturbances were identified in seven CD patients. INTERPRETATION: This retrospective longitudinal study provides long-term natural history of LAMA2-RD. This will help management and identification of key milestones of disease progression that could be considered for future therapeutic intervention.