Abstract: Objective To explore the clinical manifestation and genetic mutation of Ullrich congenital muscular dystrophy (UCMD) caused by COL 6 A1 intron variation (+ 189 C>T). Methods The clinical data of a child with UCMD were retrospectively analyzed, and the related literature was reviewed. Results A 4 -year-old girl walked independently at the age of 16 months. At the age of 24 months, the child had difficulty in getting up from squatting, needed assistance to go up and down stairs, and could not run and jump. Her proximal limbs were weak, especially in the lower limbs. The child had hyperextension of distal joints of the limbs and contracture of both knees. Creatine kinase was slightly increased. The electromyography showed myogenic damage (proximal muscles of upper and lower extremities) with mild neurogenic damage (distal muscles of upper and lower extremities). Genetic testing revealed a de novo variation in COL6A1 (NM_ 001848 . 2 ): c. 930 + 189 C>T. After the diagnosis of UCMD, the children were treated with muscle massage and rehabilitation training, and the progress of the disease was delayed. The literature search retrieved 35 children with UCMD, most of whom had relatively few symptoms in the neonatal period, and the typical clinical manifestations of UCMD gradually appeared with age. Conclusions The de novo variation of COL6A1 + 189 C > T causes delayed onset of UCMD symptoms, followed by accelerated progression.

Key words: Ullrich congenital muscular dystrophy; muscle weakness; joint deformity; COL 6 A 1 gene; intron