The case of a neonate with a rapidly fatal course of nemaline myopathy
is reported. Neonatal history and clinical findings suggested a posta
sphyxia syndrome, but dependence on mechanical ventilation in the abse
nce of severe brain damage or evidence of heart and lung involvement p
rompted us to perform a muscle biopsy. The typical rod-shaped bodies o
f nemaline myopathy were observed in skeletal and heart muscle which i
s unusual in infantile forms. Neonatal bone fractures, which have not
been reported previously, were detected. Due to the rapid evolution of
the neonatal form, many of these patients may die undiagnosed in the
perinatal period, the families remaining unaware of the existence of t
he genetic disorder. Therefore, if severe hypotonia persists in a neon
ate, together with dependence on assisted breathing, specific examinat
ions, such as muscle enzyme determination, NCV, EMG and if indicated,
muscle biopsy should be performed to rule out neuromuscular disease.