Neonatal Hypotonia and Congenital Arthrogryposis Due to a Novel PIEZO2 Gene Mutation

We report on a 39-week-old male neonate diagnosed on antenatal sonography with bilateral congenital talipes equinovarus deformity and postnatally confirmed to be having global hypotonia with decreased sensation to touch and pain. The mother is postnatally diagnosed to be having gestational diabetes. On the evaluation of the neonate, he has profound axial and appendicular hypotonia, with absent deep tendon reflexes and negligible power. The neonate has poor oromotor tone and myopathic facies, with intact sensorium and no seizures. Blood investigations including serum lactate dehydrogenase, serum lactate, and serum creatinine phosphokinase are normal. Neuroimaging including ultrasonography and magnetic resonance imaging of the brain is normal. Electroencephalogram is also normal. Whole-exome sequencing reveals a novel mutation of the PIEZO2 gene. Neonate is currently on early intervention and continues to be hypotonic at 5- month follow-up. We discuss in this manuscript this rare cause of peripheral neuropathy, its management, and prognosis.