Congenital familial myopathy with type 2 fiber hypoplasia and type 1 fiber predominance.
A 12-month-old girl with delayed developmental milestones, due to muscle hypotonia and weakness from early infancy, exhibited type 2 fiber hypoplasia. A muscle biopsy specimen disclosed type 1 fiber predominance and type 2B fiber deficiency compatible with congenital myopathy. During the following 4 years, she continued to have mild muscle weakness, but no mental retardation. Her mother had similar symptoms from early infancy with minimal progression. Although type 2 fiber hypoplasia is a non-specific finding in various diseases, it may be a specific finding in a limited number of patients with hereditary congenital non-progressive myopathy.
Muranaka
H
H
Department of Pediatrics, Hirosaki University School of Medicine, Japan. muranaka@cc.hirosaki.ac.jp
Osari
S
S
Fujita
H
H
Kimura
Y
Y
Goto
A
A
Imoto
C
C
Nonaka
I
I
D000328:Adult; D001706:Biopsy; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology*; D009123:Muscle Hypotonia / Q000151:congenital* / Q000235:genetics / Q000473:pathology*; D009468:Neuromuscular Diseases / Q000151:congenital* / Q000235:genetics / Q000473:pathology*