by Edward C. Smith, MD, and Dwight D. Koeberl, MD, PhD The rheumatologist is frequently called upon to evaluate patients with complaints of myalgia, muscle cramping, and fatigue. Because these symptoms may be nonspecific and lack any clear temporal or anatomic pattern, their workup may entail costly and uninformative tests. When similar symptoms emerge during or following physical exertion, a m...

MYOPATHIES Clinical Features Myopathies are diseases that primarily affect the muscles and are usually characterized clinically by weakness, fatigue, or stiffness (myotonia). They are usually characterized by symmetrical proximal muscle weakness and wasting, normal sensation, and normal stretch reflexes. More than one-half of muscle bulk must be lost before functional weakness can be demonstrat...

Advances in histological, biochemical, physiological and molecular biological assays, as well as in microscopy and image analysis have allowed multiple analyses in muscle tissue (1-5). Muscle biopsy is invaluable in providing a definitive diagnosis of a wide range of myopathies (muscular dystrophies, glycogen storage diseases, inflammatory myopathies and congenital myopathies) and denervating d...

FHL1 mutations cause several clinically heterogeneous myopathies, including reducing body myopathy (RBM), scapuloperoneal myopathy (SPM) and X-linked myopathy with postural muscle atrophy (XMPMA). The molecular mechanisms underlying the pathogenesis of FHL1 myopathies are unknown. Protein aggregates, designated 'reducing bodies', that contain mutant FHL1 are detected in RBM muscle but not in se...

Nemaline rod myopathy (NM) is a rare form of congenital myopathy characterized by slowly progressive or nonprogressive muscle weakness and pathognomonic rod-like structures within the muscle fibers. To the best of our knowledge, this is first documentation of the clinicopathological features of this rare entity from India. All cases of NM diagnosed in our laboratory were retrieved. Clinical and...

Protein aggregate myopathies, including myofibrillar myopathies and sporadic inclusion body myositis (sIBM), are characterized by abnormal protein aggregates composed of various muscular and ectopic proteins. Previous studies have shown the crucial role ofdysregulated transcription factors such as neuron-restrictive silencerfactor in the expression of aberrant proteins in myotilinopathies. Here...

Abstract Almost a decade ago, the sudden rise of breast muscle defects in fast-growing commercial broiler breeds challenged production industry and meat scientists to address issue these novel abnormalities. After that, widespread hypothesis showing correlation between high yield incidence myopathies received much acceptance from research community. Increased hypertrophy unbalanced growth conne...