FSHD / OPMD / EDMD / DMI: P.369A Chinese case of the early onset recessive Emery-Dreifuss-like phenotype without cardiomyopathy

Abstract

Recently, a new phenotype named the early onset recessive Emery-Dreifuss-like phenotype without cardiomyopathy was reported. The pathological gene responsible for the phenotype was located in TTN gene. Herein, we would like to report a Chinese patient with similar clinical manifestations. A 12 years old boy complained about mild difficulties in climbing and standing up from the ground since the age of 6, and muscle weakness progressed slowly with time. When he came to our clinic, he had lost the ability of walking on the heel. There was no obvious motor dysfunction in upper limbs, except for IV muscle strength of triceps brachii. Thus, weakness of bilateral distal lower limbs was prominent. Furthermore, it was hard to flex neck and extend ankle because of contractures. The malformations of feet were observed, such as pes cavus and overlength of index toes. The level of creatine kinase was 378 U/L. Muscle MRI indicated fatty infiltration and edema in the muscles of bilateral thighs and calves, but the interior group of thigh muscles was spared. The molecular analysis indicated compound heterozygous mutations in TTN gene: c.30206dupC (p.E10070Rfs*24) inherited from mother and c.21274T>C (p.C7092R) inherited from father. Additionally, mutations in genes related with Emery-Dreifuss muscular dystrophy (EMD, LMNA, SYNE1, SYNE2, FHL1) were not found. This patient has similar manifestations compared with previous reported cases but also some exclusive characteristics, which contributes to the phenotype spectrum of TTN gene mutation.