Investigators at National Center of Neur & Psych, Kodaira, Tokyo, conducted a nationwide survey of 5442 neurologists regarding the natural history of UCMD. Among 40 patients with UCMD, 33 had collagen VI deficiency. Cobb angle was >30° at age 9.9 yrs, and % vital capacity (VC) was decreased with age, with severe respiratory dysfunction before puberty. Scoliosis surgery in 3 patients at ages 5, 9 and 10 years resulted in well-maintained %VC in the youngest patient. Twenty-five (81%) of 31 patients walked independently by age 1.7 years but lost this ability by age 8.8 yrs. Six patients never walked. Age of onset varied, but scoliosis and respiratory dysfunction progressed rapidly once started. 
COMMENT. UCMD is manifested by proximal joint contractures and muscle weakness, distal joint hyperlaxity, scoliosis, and respiratory failure. Mutations in a COL6A gene are the cause.