Specific etiologies may require additional laboratory exams such as angiotensin converting enzyme dosage in sarcoidosis, complete blood count to establish eosinophilia in HESs, serum iron concentrations, total iron-binding capacity, and ferritin levels in hemochromatosis, alpha-galactosidase activity, and lyso-Gb3 levels in AFD, immunoglobulin free light chain testing, and serum and urine immunofixation in AL amyloidosis. The gene discussed is GLA; the disease is Nager acrofacial dysostosis.