7654 Unusual Case of Lipodystrophy: A Novel Disease Phenotype?

Abstract Disclosure: M. Celik Guler: None. E.D. Frontera: None. K. Hoose: None. M.C. Foss de Freitas: Advisory Board Member; Self; PTC Therapeutics. Speaker; Self; Amryt. L. Douyon: None. E.A. Oral: Advisory Board Member; Self; Amryt, Regeneron Pharmaceuticals. Consulting Fee; Self; Regeneron Pharmaceuticals, Amryt, Third Rock Ventures. Grant Recipient; Self; Regeneron Pharmaceuticals, Amryt. Research Investigator; Self; Novo Nordisk, Ionis Pharmaceuticals Inc., Fractyl, GI Dynamics, Rhythm Pharmaceuticals. Other; Self; Amryt. Background: Lipodystrophy syndromes (LD) are rare disorders characterized by varying degrees of adipose tissue deficiency that can predispose individuals to severe metabolic complications. Although these syndromes are traditionally subclassified based on inheritance patterns and the degree of adipose tissue loss, patients may exhibit highly heterogeneous clinical presentations. In this context, we report a unique case of partial lipodystrophy with an unusual distribution of adipose tissue that likely represents a novel syndrome and challenges conventional phenotypes. Clinical Case: A 60-year-old Puerto Rican female patient with medical history of type 1 diabetes mellitus (DM), obesity, hyperlipidemia, irritable bowel syndrome, asthma, and coronary artery disease was referred to us for unexplained asymmetric distribution of adipose tissue. She had chronic left posterolateral hip pain and lipoatrophy in her left lower extremity. Her medical history showed that she was born approximately 7 lbs., with no evidence of trauma during delivery. Her mother was given an unknown medication for improving circulation to the placenta. She had a morphea like rash on the arms and chest wall more prominent on the left upper body at birth. In addition, a dimple on her hip was noticed by her mother during the early stages of infancy. Despite the normal progression of neurological development (walking/climbing stairs), she always had a very mild limp. Also, her right arm was always 2 inches larger than her left arm. When she gained weight, she also put on more asymmetric weight on the left side of the abdomen and left lower torso. She had been treated with insulin injections since she was diagnosed with diabetes at the age of 11. She never demonstrated any islet cell specific antibodies. She had a normal weight until pregnancy at the age of 27, during which she gained 20 lbs. Her weight continued to increase over time, and the maximum was 212 lbs. Her examination reveals a BMI of 41.46 kg/m² with excess fat in the right arm, mid-section, left thigh, and left mons pubis. Conversely, only the left leg appears to demonstrate specific fat atrophy, with a near-total loss of adipose tissue starting from the mid-gluteal region. The hip MRI result reported moderate osteoarthritis of the left hip. EMG revealed signs of length-dependent sensorimotor axonal polyneuropathy and long duration/large amplitude motor unit potentials isolated only in the left medial gastrocnemius muscle. Triglyceride level was 73 mg/dL, HbA1c level was 6.8%, with an average total insulin dosage of around 43 IU/day. There was no history of pancreatitis due to hypertriglyceridemia. Conclusion: Our case highlights the heterogeneity of the lipodystrophy spectrum with a novel presentation of lipodystrophy. In addition, there may be homeostatic control of deposition of fat to seek symmetry between upper versus lower and right versus left sided depots. Presentation: 6/1/2024