ACTA1 and myopathy: Care was withdrawn on day 18 due to poor neurologic recovery.<h4>Conclusion</h4>This case highlights three critical implications: (1) the significant clinical overlap between <i>ACTA1</i> myopathy and perinatal asphyxia, underscoring the necessity of genetic testing in hypotonic neonates with atypical presentations; (2) the grave prognosis of early-onset <i>ACTA1</i> mutations, which mandates early palliative care consultation; and (3) the essential role of a precise genetic diagnosis in defining phenotypes and informing future targeted therapies, such as gene therapy.