All are Congenital Myopathies, Except:
Answer is C (Z band Myopathy): Z band myopathy is not classified as a congenital myopathy. Nemaline myopathy, Central-core myopathy and Centro-nuclear (Myotubular) myopathy are all examples of congenital mvopathie.s Congenital Myopathies These are a group of rare disorders distinguished from muscular dystrophies by the presence of specific histochemical and structural abnormalities in muscle. Onset in early life (primarily disorders of infancy & childhood, but may present in adulthood) Non progressive or slowly progressive course Proximal or generalized muscle weakness Hipotonia Disease and Inheritance Gene and Locus Clinical Findings logic Findings Central core disease; Ryanodine receptor-1 (RYRI) gene; Early-onset hypotonia and non Cytoplasmic cores are lightly Autosomal-dominant 19q 13.1 progressive weakness; associated skeletal deformities; may develop malignant hypehermia eosinophilic and distinct from surrounding sarcoplasm; Found only in type I fibers, which usually predominate, best seen on NADH stain Nemaline myopathy; Autosomal-dominant Weakness, hypotonia and Aggregates of subsarcolemmal Autosoma-dominant or (N EMI) -- Tropomyosin 3 delayed motor development in spindle shaped paicles Autosomal-recessive (TPM3) gene; childhood; may also be seen in (nemaline rods); occur Autosomal-recessive (NEM2) -- nebulin (NEB) gene; 2q22 adults; usually nonprogressive; involves proximal limb muscles most predominantly in type 1 fibers; derived from Z-band material (a-actinin) and best seen on Autosomal-dominant or recessive -- skeletal muscle actin, a chain severely; skeletal abnormalities may be present modified Gomori stain (ACTA I) gene; 1q42.1 Myotubular myopathy X-linked-myotubularin (MTM1) X-linked form presents in Abundance of centrally located (Centronuclear); gene; Xq28 infancy with prominent nuclei involving the makority of X-linked (MTMI), Autosomal recessive, or Autosomal-dominant hypotonia and poor prognosis; autosomal forms have limn weakness and are slowly progressive; autosomal recessive form is intermediate in severity and prognosis muscle fibers; central nuclei are usually confined to type I fibers, which are small in diameter, but can occur in both fiber types er uncommon types include minicore myopathy, fingerprint body myopathy and sarcotubular myopathy.
Central-core Myopathy
Nemaline Myopathy
Z band Myopathy
Centro-nuclear Myopathy