2.1.2 Emery-Dreyfus muscular dystrophy (EDMD)

EDMD is a muscular disorder with different inheritance patterns: X-linked recessive or autosomal dominant or autosomal recessive [25, 26]. The clinical picture includes the classical triad: (i) early joint contractures, (ii) slowly progressive muscle weakness and wasting in humeroperoneal distribution (upper arm, lower legs), and (iii) cardiac disease (atrial-ventricular conduction anomalies, atrial arrhythmias) [27]. Usually, the clinical presentation is characterized by Achilles contractures with toe walking in childhood. Later, arm weakness and elbow contractures develop, associated with biceps or triceps wasting with sparing of deltoid muscle (a characteristic pattern called "Popeye arms." A rigid spine is also present causing a severe lumbar lordosis [27].

retinal vasculopathy characterized by aneurysmal dilatations and exudation, which can cause retinal detachment or blindness; loss of high-frequency hearing, usually asymptomatic; hearing loss; and intellectual disability and seizures in infants with

A careful, complete, and thorough clinical examination along with laboratory investigations provides more information necessary for management of patients with muscular dystrophy, differentiates between the type of muscular dystrophy,

When a muscular dystrophy is suspected, blood enzyme test and a variety of laboratory test can be used for confirmation of clinical diagnosis. The blood serum samples are used to determine the level of specific enzymes known to have a high

i. Creatine kinase (CK) also known as creatine phosphokinase (CPK), an

The level of CK has been found higher in other types of MD like limb-girdle muscular dystrophy (LGMD) [17] and could serve as useful indicator being able to discriminate between autosomal recessive and dominant types of LGMD, knowing that CK level recessive types of MD are higher than dominant ones. Also, evaluation

It is interesting to note that not all cases of MD show a high level of CK. For example, in Ullrich congenital muscular dystrophy, Emery-Dreifuss muscular dystrophy, and Bethlem myopathy, the level of CK may be normal or slightly

ii. Aldolase, transaminases (alanine aminotransferase ALT and aspartate

Also, from the blood collected on anticoagulant (EDTA), total genomic DNA is

Other laboratory tests like electromyography, magnetic resonance imaging (MRI), combined with muscle biopsy, and genetic tests contribute for toward a diagnosis.

The assessment of skeletal muscle biopsy is an essential procedure for an accurate diagnosis when a muscle disease is suspected, providing evidence of patholog-

aminotransferase AST), and lactate dehydrogenase (LDH) are other muscle enzymes also reported with a rise level in blood serum [18] when a muscular

of CK level is a useful screening tool for female DMD carrier.

isolated for further genetic tests used to confirm the diagnosis.

ical changes in muscle and guides for appropriate tests.

intracellular enzyme found with relative predominance in skeletal muscle, is considered as the most specific and sensitive marker of muscle disease. Normal reference value of CK ranges between 60 and 174 IU/L into blood serum [13, 14]. Elevated level of CK could suggest a muscle disease before symptoms of muscular dystrophy become evident [33, 34]. In early stages of the muscle disease, CK levels are 20–300 times greater than normal levels and tend to decrease with the muscle damage [15]. In male DMD patients, the serum CK level is markedly elevated due to muscle degeneration [17] with less elevation level noted in BMD patients. Recent studies show that losses of lung function in DMD patients determine the high level of CK in blood serum [35].

FSHD [32, 33].

increased [22].

2.3 Muscle biopsy

13

dystrophy is suspected.

and directs to subsequent analyses.

blood serum levels when a dystrophic process is present:

Clinical and Molecular Diagnosis in Muscular Dystrophies

DOI: http://dx.doi.org/10.5772/intechopen.85339

2.2 Laboratory investigations
