Limb-girdle muscular dystrophy type 2D: clinical and genetic analysis of a family

Abstract

Objective To study the characteristics and diagnosis of limb-girdle muscular dystrophy type 2D (LGMD2D).  Methods The clinical characteristics, EMG, muscle MRI and muscle pathological studies of 2 female patients in a family with LGMD2D were analyzed. Genetic analysis was used in the diagnosis of this disease. The cases were reported along with related literatures review. Results The onset of the proband and her younger sister occurred at 3 years old with progressive proximal muscle weakness of four limbs as the main clinical manifestation. The serum creatine kinase (CK) was significantly high (> 50 × 10 3 U/L). EMG showed myogenic damage. Muscle MRI indicated partial muscle atrophy, fatness or fiber edema. Muscle pathological examination of the proband's younger sister revealed skeletal muscle necrosis and focal regeneration, partial striated muscle disappearance, and the muscle fibers in different sizes. Sequencing of all 10 coding exons of the SGCA gene in 2 patients revealed the same mutation: a c.262delT (p.Phe88SerfsX123) frameshift mutation in exon 3 and a c.409G > A (p.Glu137Lys) missense mutation in exon 5. Their mother was a carrier of SGCA gene c.409G > A (p.Glu137Lys) mutation. c.409G > A (p.Glu137Lys) is a mutation already found, and c.262delT (p.Phe88SerfsX123) is a novel mutation. The proband's father did not take the genetic test for some reason.  Conclusions In case of a female with Duchenne muscular dystrophy (DMD).like symptom, if she has been excluded from the DMD gene carrier, pedigree analysis and genetic analysis involving limb . girdle muscular dystrophy (LGMD) should be conducted to facilitate the diagnosis of the LGMD and its subtypes.

DOI: 10.3969/j.issn.1672-6731.2017.08.010