CIDEC-related familial partial lipodystrophy: A Patient Guide

CIDEC-related familial partial lipodystrophy, also known as FPLD5, is a very rare genetic condition that changes how your body stores and manages energy. Because FPLD5 is so rare, individual features can vary significantly from person to person, and this guide does not replace a clinician’s individualized care plan.

At its core, this is a disorder of the fat cells, or adipocytes. In a healthy body, these cells act as storage tanks for fat, keeping it safely tucked away until the body needs it for fuel. In people with FPLD5, a mutation in the CIDEC gene disrupts the specialized machinery required to build these storage tanks, which can lead to a cascade of metabolic challenges ^[1].

The biological mechanism behind FPLD5 involves a failure of lipid droplet fusion. Normally, the CIDEC protein allows tiny droplets of fat within a cell to merge into one large, stable droplet ^[2]. Without a functional CIDEC protein, the fat remains fragmented into many tiny droplets that the cell cannot manage effectively. Because these cells can no longer provide safe storage, the body may lose fat in certain areas—most notably from the arms, legs, and buttocks—while compensating by storing fat in the face, neck, and trunk ^[1].

When the natural storage areas under the skin fail, the fat may be redirected into organs that were never meant to hold it, such as the liver and skeletal muscles. This redistribution, known as ectopic fat storage, can trigger severe insulin resistance. This resistance is a major driver behind the condition’s primary medical complications: type 2 diabetes, elevated levels of blood fats (hypertriglyceridemia), and fatty liver disease ^[1][3]. Not every person develops every listed problem, and severity varies.

While living with such a rare condition can be daunting, a diagnosis of FPLD5 provides a framework for your care. Although there is currently no cure for the underlying genetic mutation, the metabolic complications can be treated through a dedicated, coordinated approach. By working with your clinical team to focus on tailored nutrition and targeted medications, you can manage your risks and work to protect your long-term health ^[4].