TY - JOUR
T1 - Severe congenital actin related myopathy with myofibrillar myopathy features
AU - Selcen, Duygu
N1 - Funding Information:
This work was supported by the Mayo Clinic Center for Individualized Medicine .
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Mutations in ACTA1 have been associated with different pathologic findings including nemaline myopathy, intranuclear rod myopathy, actin myopathy, cap myopathy, congenital fiber type disproportion, and core myopathy. Myofibrillar myopathies are morphologically distinct but genetically heterogeneous muscular dystrophies arising from mutations in Z-disk related proteins. We report a 26-month-old boy with significantly delayed motor development requiring mechanical ventilation and tube-feeding since birth. The muscle biopsy displayed typical features of myofibrillar myopathy with abnormal expression of multiple proteins. Whole exome sequencing revealed two-amino-acid duplication in ACTA1. In cell culture system, mutant actin was expressed at ~11% of wild-type, and mutant actin formed pleomorphic cytoplasmic aggregates whereas wild-type actin appeared in filamentous structures. We conclude that mutations in ACTA1 can cause pathologic features consistent with myofibrillar myopathy, and mutations in ACTA1 should be considered in patients with severe congenital hypotonia associated with muscle weakness and features of myofibrillar myopathy.
AB - Mutations in ACTA1 have been associated with different pathologic findings including nemaline myopathy, intranuclear rod myopathy, actin myopathy, cap myopathy, congenital fiber type disproportion, and core myopathy. Myofibrillar myopathies are morphologically distinct but genetically heterogeneous muscular dystrophies arising from mutations in Z-disk related proteins. We report a 26-month-old boy with significantly delayed motor development requiring mechanical ventilation and tube-feeding since birth. The muscle biopsy displayed typical features of myofibrillar myopathy with abnormal expression of multiple proteins. Whole exome sequencing revealed two-amino-acid duplication in ACTA1. In cell culture system, mutant actin was expressed at ~11% of wild-type, and mutant actin formed pleomorphic cytoplasmic aggregates whereas wild-type actin appeared in filamentous structures. We conclude that mutations in ACTA1 can cause pathologic features consistent with myofibrillar myopathy, and mutations in ACTA1 should be considered in patients with severe congenital hypotonia associated with muscle weakness and features of myofibrillar myopathy.
KW - Actin
KW - Myofibrillar myopathy
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U2 - 10.1016/j.nmd.2015.04.002
DO - 10.1016/j.nmd.2015.04.002
M3 - Article
C2 - 25913210
AN - SCOPUS:84929652897
VL - 25
SP - 488
EP - 492
JO - Neuromuscular Disorders
JF - Neuromuscular Disorders
SN - 0960-8966
IS - 6
ER -