The current invention pertains to a method of diagnosing a disease or identifying an increased likelihood of developing the disease in a subject. The method comprises determining the level of Src homology 3 domain binding protein 5 (SH3BP5 or SAB) or the RNA encoding SAB protein in a biological sample obtained from the subject and identifying the subject as having the disease or having an increased likelihood of developing the disease if the biological sample obtained from the subject has an altered level of SAB protein or the RNA encoding SAB protein relative to a control sample. The methods of the current invention can be practiced to diagnose and treat a systemic degenerative disease, a neurodegenerative disease, obesity, diabetes, a cancer, or an aging related disease. The invention also provides a kit for diagnosing a disease or diagnosing an increased likelihood of developing the disease in a subject.