Produção Nacional
Revisado por pares
Necklace fibers as histopathological marker in a patient with severe form of X-linked myotubular myopathy
2012; Elsevier BV; Volume: 22; Issue: 6 Linguagem: Inglês
10.1016/j.nmd.2011.12.005
ISSN1873-2364
AutoresJuliana Gurgel‐Giannetti, Edmar Zanoteli, Eralda Luiza de Castro Concentino, Osório Lopes Abath Neto, João Bosco Pesquero, Umbertina Conti Reed, Mariz Vainzof,
Tópico(s)Cellular transport and secretion
ResumoX-linked myotubular myopathy due to mutations in the MTM1 gene is classically characterized by a severe neonatal phenotype and a typical muscle biopsy presenting globular and centrally located nuclei in muscle myofibers. Recently, four patients with mild late-onset form have been described, a male with a hemizygous mutation and three females with heterozygous mutations in the MTM1 gene. The muscle biopsies were performed at 13–35 years of age and a new histological marker, the necklace fibers, was described. Here, we report two siblings with the pathogenic c.664 C > T mutation in the MTM1 gene, presenting a severe muscle weakness and respiratory impairment requiring ventilatory support since the first months of life until death, at the age of 36 months and 5 months. In the older brother the muscle biopsy, performed at the age of 30 months, showed almost 100% of necklace fibers, which were not present in the younger one submitted to muscle biopsy at 5 months of age. Our findings confirm the necklace fibers can be a histopathological finding of MTM1 myopathies, even in the severe neonatal form, and suggest that the necklace fibers appear or increase in number over time.
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