IMR Press / JIN / Volume 20 / Issue 1 / DOI: 10.31083/j.jin.2021.01.267
Open Access Case Report
c.3G>A mutation in the CRYAB gene that causes fatal infantile hypertonic myofibrillar myopathy in the Chinese population
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1 Department of Neuromuscular Research Lab, Shenzhen Children’s Hospital, 518038 Shenzhen, P. R. China
2 Department of Neurology, Shenzhen Children’s Hospital, 518038 Shenzhen, P. R. China
3 Running Gene Inc.,100083 Beijing, P. R. China
*Correspondence: (Chun-Xi Han)
J. Integr. Neurosci. 2021, 20(1), 143–151;
Submitted: 5 September 2020 | Revised: 18 November 2020 | Accepted: 3 December 2020 | Published: 30 March 2021
Copyright: © 2021 The Authors. Published by IMR Press.
This is an open access article under the CC BY 4.0 license (

Infantile hypertonic myofibrillar myopathy is characterized by the rapid development of rigid muscles and respiratory insufficiency soon after birth, with very high mortality. It is extremely rare, and only a few cases having been reported until now. Here we report four Chinese infants with fatal neuromuscular disorders characterized by abdominal and trunk skeletal muscle stiffness and rapid respiratory insufficiency progression. Electromyograms showed increased insertion activities and profuse fibrillation potentials with complex repetitive discharges. Immunohistochemistry staining of muscle biopsies showed accumulations of desmin in the myocytes. Powdery Z-bands with dense granules across sarcomeres were observed in muscle fibers using electron microscopy. All patients carry a homozygous c.3G>A mutation in the CRYAB gene, which resulted in the loss of the initiating methionine and the absence of protein. This study’s findings help further understand the disease and highlight a founder mutation in the Chinese population.

Myofibrillar myopathy
Neuromuscular disease
CRYAB mutation
Fig. 1.
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