Abstract

Background: Congenital myopathies are a diverse group of diseases that share features from the early onset of symptoms in the first year of life, such as hypotonia, muscle weakness, and developmental delays, and are often associated with respiratory insufficiency and feeding difficulties.
Case presentation: Here, we report an 8-year-old boy having hypotonia and signs of respiratory insufficiency that ended with tracheostomy and ventilator-dependent status. Muscle biopsy showed histological findings of congenital fiber-type disproportion myopathy. The whole exome sequencing revealed a novel hemizygous missense variant (c.530A > C p.Gln177Pro) that confirms the diagnosis of FHL1-associated congenital myopathy.
Conclusion: The findings in this study help to expand the genetic and mutational spectrum of the FHL1 gene associated with respiratory insufficiency and help in formulating a precise strategy for prognosis and future management of patients.

Key words: Congenital myopathy, FHL1, hypotonia, congenital fiber-type disproportion myopathy, and X-linked myopathy