Published online Apr 16, 2021. doi: 10.12998/wjcc.v9.i11.2569
Peer-review started: December 25, 2020
First decision: January 10, 2021
Revised: January 23, 2021
Accepted: February 8, 2021
Article in press: February 8, 2021
Published online: April 16, 2021
Nemaline myopathy (NM) is a rare type of congenital myopathy, with an incidence of 1:50000. Patients with NM often exhibit hypomyotonia and varying degrees of muscle weakness. Skeletal muscles are always affected by this disease, while myocardial involvement is uncommon. However, with improvements in genetic testing technology, it has been found that NM with a mutation in the myopalladin (MYPN) gene not only causes slow, progressive muscle weakness but also results in dilated or hypertrophic cardiomyopathy.
A 3-year-old pre-school boy was admitted to our hospital with cough, edema, tachypnea, and an increased heart rate. The patient was clinically diagnosed with severe dilated cardiomyopathy and heart failure, and subsequent gene examination confirmed the diagnosis of NM with a mutation in MYPN. Captopril, diuretics, low-dose digoxin, and dobutamine were administered. After 22 d of hospitalization, the patient was discharged due to the improvement of clinical symptoms. During the follow-up period, the patient died of refractory heart failure.
Decreased muscular tone and dilated cardiomyopathy are common features of MYPN-mutated NM. Heart transplantation may be a solution to this type of cardiomyopathy.
Core Tip: Nemaline myopathy (NM) is a rare kind of congenital myopathy, with an incidence of 1:50000. The pathological characteristic is accumulated “rod” shaped structures in the muscle biopsies observed by light or electron microscopy. NM patients often have hypomyotonia and different degrees of muscle weakness. Skeletal muscles are always involved in this disease, while myocardial involvement is uncommon. However, it has been recognized that NM with mutation in myopalladin (MYPN) gene also results in dilated cardiomyopathy or hypertrophic cardiomyopathy. Here, we report the case of a 3-year-old boy with NM who was admitted with dilated cardiomyopathy and heart failure followed by genetic confirmation of NM with an MYPN mutation.