Excessive accumulation of lipids in tissues not designed for long term storage may underlie the clinical manifestations of weakened skeletal and cardiac muscle, fatty liver, pancreatitis, hypothyroidism, and type 2 diabetes. Diagnosis
Main physical signs include a fatty liver, a weakened and enlarged heart (cardiomyopathy), inflammation of the pancreas (pancreatitis), reduced thyroid activity (hypothyroidism), type 2 diabetes, abnormal levels of creatine kinase in blood, and increased weakness of proximal muscles due to fatty replacement of skeletal muscle fibers. Accurate diagnosis is complicated by symptomatic overlap with other disorders. One of the earliest symptoms to manifest clinically is peripheral limb weakness, which becomes progressively more severe over time. Specifically, asymmetric right shoulder weakness is an idiosyncratic hallmark of NLSD enabling it to be distinguished from myopathies arising from alternative muscular disorders. NLSD is often diagnosed by the presence of lipid inclusions within leukocytes (Jordan’ Anomaly), which can be detected using histochemical and electron microscopy. Image B shows the characteristic lipid accumulation in red blood cells, in a NLSD patient, as compared to a normal individual (Image A). Classically, NLSD is associated with myopathy and can, in some cases, be linked with icthyosis. Therefore, with these symptoms or diagnosis, it is likely that the patient could and would be diagnosed with NLSD. Although lipid accumulation is most prominent in  myocytes, hepatocytes, and granulocytes, other tissues displayed elevated deposits as well. For the purpose of diagnosis, MRIs have been used to identify large fat deposits within muscle tissue.
Disruption of CGI-58 gives rise to the symptoms of ichthyosis, a dermatological condition in which skin becomes very scaly, thick and dry.Ichthyosis is an inherited disorder, like NLSD, and has been found to be genetically linked in some situations with the PNPLA2 gene. Therefore, sometimes when there is a mutation in the PNPLA2 gene, the linked allele of CG-58 is mutated as well. This specific gene, however, does not produce ichthyosis on its own. Ichthyosis can be diagnosed individually in a patient and the genetic cause for unlinked ichthyosis is different from the gene linked with PNPLA2. Keep in mind these disorders may occur individually within a patient as well. Pathophysiology
The functional changes that occur with this disease are mostly metabolic. Accumulation of triglycerides in the body without an efficient mode for catabolism is thought to lead to the eventual symptoms of this disease. Upon digestion and absorption of fat by the small intestine, triglycerides are combined with vitamins and cholesterol to form chylomicrons. Chylomicrons travel from the intestine into the lymph system before entering the bloodstream. Enzymatic catalysis of chylomicrons by lipases in the bloodstream enables the uptake of lipids and fatty acids by cells. In individuals with NLSD, their triglycerides are not catabolized in the blood, and cells accumulate partially processed lipid droplets over time, which may lead to dysfunction in absorbing tissues. In affected individuals, muscle cells, fibroblasts, and leukocytes appear to be prone to the excessive accumulation of triglycerides as lipid droplets.