Severe Hypertrophic Cardiomyopathy Caused by a Protein Kinase Adenosine Monophosphate-Activated Non-catalytic Subunit Gamma 2 (PRKAG2) Mutation With Refractory Chylous Effusions in a Neonate: A Case Report and Literature Review. Here, PRKAG2 is linked to hypertrophic cardiomyopathy.