When mutations occur in the PNPLA2 gene, this results in the development of neutral lipid storage disease with myopathy. The PNPLA2 gene has instructions for making an enzyme ATGL (adipose triglyceride lipase). As you’ve mentioned, this enzyme plays a vital role in the process of breaking down LDs, which allows to use them for energy once they are broken down into smaller molecules. Mutations in the PNPLA2 gene impair the ATGL ‘s ability to participate in LDs’ lipolysis, and they begin to accumulate in muscle and tissues of the body. This leads to the development of neutral lipid storage disease with myopathy. Another gene – CGI58 – activates the PNPLA2 gene, and mutations in that gene result in ichthyosis and hepatic symptoms. Though as of to date the biochemical basis and pathogenesis of NLSDs are not fully understood, is known that the two enzymes release triglycerides from cytoplasmic LDs in order to supply beta-oxidation in energy production into mitochondria and to build cellular membranes.