All are congenital myopathies EXCEPT :
Centralcore myopathy
Nemaline myopathy
Z band myopathy
Centronuclear myopathy
Answer is C (Z band Myopathy) Z band myopathy is not classified as a congenital myopathy. Congenital Myopathy: These are a group of rare disorders distinguished from muscular dystrophies by the presence of specific histochemical and structural abnormalities in muscle. Most of these are characterized by : 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 Hypotonia Congenital Myopathies: Disease and Inheritance Gene and Locus Clinical Findings Pathologic 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 (NEM 1) -- 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 ressive. involves nonprog 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 X-linked-myotubularin (MTM 1) X-linked form presents in Abundance of centrally located (centronuclear) gene; Xq28 infancy with prominent nuclei involving the makority of myopathy; X-linked hypotonia and poor prognosis; muscle fibers; central nuclei are (MTM I ), autosomal recessive, or autosomal- autosomal forms have limn weakness and are slowly usually confined to type I fibers, which are small in diameter, but dominant progressive; autosomal recessive form is intermediate in severity and prognosis can occur in both fiber types Other uncommon types include minicore myopathy, fingerprint body myopathy and sarcotubular myopathy.