The advances made in muscle biopsy in Jordan, now, are becoming able to diagnose many of the muscle types of dystrophies with certainty
Introduction: the muscle membrane is peculiar among other cell membranes by having complex of proteins that are attached to the muscle membrane, that are very important for its integrity and action. The complex includes dystrophin and glycoprotein complex (DGC). This complex has several proteins. The defect in them leads to muscle dystrophies of various types, as indicated below
:The following diseases can be diagnosed or excluded with certainty in our lab
Duchenne and Becker�s muscular dystrophy: due to deficiency of dystrophin protein. Staining for dystorphin can be done in paraffin blocks
Limb girdle muscular dystrophy (LGMD) syndrome: divided into autosomal dominant form (Type 1); autosomal recessive form (type 2). we can diagnosis with certainty in our lab the following diseases of limb girdle syndrome
Type LGMD2b: due to deficiency of dysferlin. It is a common form and accounts up to 30% of the LGMD cases. This protein is important for the integrity of the muscle membrane and part of the Dystrophin-Glycoprotein Complex. The disease manifestation varies. The disease may present initially with gastrocnemius weakness and they will be unable to walk on their toes. Age of onset is between 10-late 30s. Wheelchair confinement occurs around 30 years after onset. Staining for dysferlin can be done on muscle tissue. The same mutation occurs in Mioshi distal myopathy
Type LGMD 2D: due to decrease or absence of Adhalin (alpha sacroglycan) in muscle membrane. This disease is common in the Arab countries. This mutation is 4 times as common as mutation in beta (2E) and gamma sacroglycan. (2C). Age of onset is between 2-15 years. Patients with early onset have rapid progression to wheelchair, while patient with later onset may have preserve ambulation. Staining for Adhalin can be done by immunohistochemical stain on frozen muscle tissue
Merosin Laminin Alpha 2 chain deficiency: this protein is part of Dystorphin-Glycoprotein complex. Autosomal recessive congenital muscular dystrophy due to decreased or deficiency of Merosin in the basement membrane. It is characterized by symmetrical proximal and distal weakness, with contractures. Serum CPK: moderately high. MRI of CNS: increased T2 signal in white mater. Staining for Merosin can be done by immunohistochemical stain on frozen muscle tissue
Emery-Drefuss muscular dystrophy : X linked form; due to deficiency in Emerin. It is localized in the nuclear membrane; characterized by slowly progressive contractures in elbow and neck (differential: Bethlem myopathy) , wasting of scapulohumeroperoneal muscles (differential: scapuloperoneal muscular dystrophy) and cardiomyopathy (with conduction heart block, presenting as syncope). CPK mildly elevated. Staining for Emerin can be done by on formalin fixed muscle tissue
We, in the First Medical Laboratory , are determined to bring the best of laboratory medicine in clinical practice to Jordan
Please call us for any further information
.Dr. Hussam Abu-Farsakh, M.D
American boards of Anatomic, clinical pathology & Cytopathology