Familial partial lipodystrophy (FPLD) is a group of inherited disorders in which subcutaneous fat is lost from particular body regions while it is preserved or accumulates elsewhere. The visible fat pattern is only one part of the condition. When healthy adipose tissue cannot expand normally, excess energy is redirected to the liver, muscle, and bloodstream, contributing to severe insulin resistance, diabetes, high triglycerides, fatty liver disease, pancreatitis, polycystic ovary features, and premature cardiovascular disease. Genetic testing often includes LMNA and PPARG, the principal genes for Dunnigan-type FPLD2 and FPLD3. These disorders overlap metabolically but are not identical. LMNA variants may also require assessment for cardiomyopathy, conduction disease, or skeletal muscle involvement, while PPARG variants directly affect adipocyte development and insulin sensitivity. A pathogenic result can confirm the subtype and guide family testing, but a negative panel does not exclude partial lipodystrophy. Diagnosis still depends on body-fat distribution, metabolic findings, imaging when needed, and exclusion of common mimics.
- FPLD is a disorder of fat storage capacity, not simply low body fat or central obesity.
- Loss of limb and gluteal fat can coexist with fat accumulation in the face, neck, abdomen, or internal organs.
- LMNA-related FPLD2 often becomes more apparent around puberty and may carry cardiac or muscle implications.
- PPARG-related FPLD3 can be subtle externally despite severe diabetes, triglyceride elevation, and fatty liver.
- A positive genetic result supports subtype-specific surveillance and targeted testing of relatives.
- Treatment focuses on metabolic complications, cardiovascular risk, nutrition, and individualized use of specialized therapies.
Table of Contents
- Recognizing partial lipodystrophy
- LMNA-related FPLD2
- PPARG-related FPLD3
- Who should consider genetic testing
- How the test and results work
- Metabolic and cardiac evaluation
- Treatment and daily management
- Family screening and reproductive planning
Recognizing partial lipodystrophy
Adipose tissue is an active endocrine and metabolic organ. It stores triglyceride safely, releases energy when needed, and produces hormones that help regulate appetite, insulin sensitivity, inflammation, and reproductive function. In lipodystrophy, the problem is not merely appearance; there are too few functional fat cells in certain compartments to store incoming energy appropriately.
Excess fatty acids then circulate or accumulate in the liver and skeletal muscle. The pancreas produces more insulin to compensate for resistance. Over time, this can lead to acanthosis nigricans, hyperinsulinemia, diabetes, severe hypertriglyceridemia, metabolic dysfunction-associated steatotic liver disease, and pancreatitis. Cardiovascular risk increases through diabetes, dyslipidemia, hypertension, inflammation, and, in some LMNA-related families, direct myocardial disease.
Partial lipodystrophy can be difficult to recognize because fat loss may be interpreted as muscularity, athletic build, ordinary aging, or successful weight loss. The limbs may appear defined with prominent veins and muscles, while fat is retained around the face, neck, dorsocervical region, or abdomen. Gluteal fat loss, reduced thigh circumference, and scarcity of subcutaneous tissue over the arms and legs are important clues.
The timing and distribution vary by subtype. Some people appear typical in childhood and develop visible changes around puberty. Women are often recognized more readily because the expected postpubertal fat distribution makes limb and hip fat loss conspicuous. Men may be missed because a muscular appearance can seem socially typical. Metabolic severity can be substantial in either sex.
FPLD should be distinguished from common central obesity, weight loss, malnutrition, advanced illness, Cushing syndrome, HIV-associated lipodystrophy, medication effects, and acquired partial lipodystrophy. Body composition imaging with dual-energy X-ray absorptiometry or MRI can document regional fat loss and visceral or hepatic fat, but no single scan establishes the diagnosis.
A careful examination looks beyond total body mass index. A person can have a normal or high BMI and still lack metabolically protective subcutaneous fat in the limbs. Waist circumference, skinfolds, gluteofemoral contour, acanthosis, xanthomas, hepatomegaly, and muscular prominence add information. Historical photographs can show how distribution changed around puberty or pregnancy.
Laboratory clues include diabetes that seems unusually insulin-resistant, triglycerides that are markedly elevated despite therapy, low HDL cholesterol, fatty liver without a typical degree of obesity, high insulin requirements, or recurrent pancreatitis. Reproductive features can include irregular cycles, hyperandrogenism, polycystic ovaries, subfertility, and pregnancy complications.
LMNA-related FPLD2
LMNA encodes lamins A and C, proteins that form part of the nuclear envelope and influence nuclear structure, gene regulation, and cellular responses to mechanical stress. Variants in LMNA can cause several different laminopathies. The classic Dunnigan form of familial partial lipodystrophy, called FPLD2, is most often associated with heterozygous missense variants affecting a specific region of lamin A/C, including recurrent changes at residue 482.
People with classic FPLD2 often have normal fat distribution during childhood. Around puberty, subcutaneous fat progressively decreases from the arms, legs, buttocks, and trunk. Fat may accumulate in the face, neck, supraclavicular region, back, abdomen, and intra-abdominal compartment. Muscles and superficial veins become prominent. Women frequently develop more severe metabolic complications than men.
Insulin resistance can lead to early diabetes, sometimes requiring high insulin doses. Triglycerides may rise enough to cause eruptive xanthomas or pancreatitis. Fatty liver can progress to inflammation and fibrosis. Hypertension and premature atherosclerotic cardiovascular disease are important long-term concerns.
Not every LMNA variant causing lipodystrophy has the classic Dunnigan appearance. Some produce atypical fat loss, progeroid features, skeletal abnormalities, neuropathy, muscle weakness, or overlapping syndromes. The report must therefore be interpreted with the exact variant and phenotype rather than assuming that any pathogenic LMNA result means FPLD2.
LMNA also has major cardiac disease associations. Variants in other regions or mechanisms can cause dilated cardiomyopathy with atrioventricular block, atrial arrhythmias, and ventricular arrhythmia. Some people with lipodystrophy-associated LMNA variants may also develop cardiomyopathy or conduction abnormalities, although cardiac risk varies by variant and family. Baseline ECG, cardiac imaging, and family history review are prudent after a pathogenic LMNA result, with ongoing surveillance determined by the genetics and cardiology teams.
Musculoskeletal assessment may be needed when there is weakness, contracture, reduced mobility, or elevated creatine kinase. The presence of one LMNA manifestation does not guarantee another, but the gene’s broad phenotype makes a focused review of the heart and skeletal muscle more important than in many purely metabolic disorders.
Inheritance is usually autosomal dominant. Each child of an affected person has a 50% chance of inheriting the variant. Expression can vary, and a parent with mild fat loss or diabetes may have gone unrecognized. A de novo variant is also possible.
PPARG-related FPLD3
PPARG encodes peroxisome proliferator-activated receptor gamma, a nuclear receptor and transcription factor central to adipocyte differentiation, lipid storage, and insulin sensitivity. Pathogenic loss-of-function variants can reduce the body’s capacity to form and maintain functional adipose tissue. This causes FPLD3, generally inherited in an autosomal dominant manner.
The external fat-loss pattern in FPLD3 can be less dramatic than in classic LMNA-related Dunnigan lipodystrophy. Some people have distal limb and gluteal fat loss, while others appear only mildly lean in the extremities. The metabolic phenotype may be disproportionately severe: early diabetes, high triglycerides, hypertension, fatty liver, low HDL cholesterol, and polycystic ovary features can occur despite subtle physical changes.
PPARG variant interpretation requires mechanism-specific evidence. The gene is intolerant of some functional changes, but not every rare missense variant is pathogenic. Evidence may include impaired transcriptional activation, altered DNA or ligand binding, dominant-negative effects, segregation with lipodystrophy, and absence from population databases. Variants can occur in different protein domains and may produce variable severity.
PPAR gamma is the pharmacologic target of thiazolidinediones such as pioglitazone. This does not mean every person with a PPARG variant will respond or that such medication is always appropriate. Some variants may reduce receptor function in ways that limit benefit, while fluid retention, weight gain, fracture risk, heart failure, and other adverse effects can constrain use. Treatment decisions are empirical and supervised.
Unlike LMNA, PPARG is not typically a primary cardiomyopathy gene. Cardiovascular surveillance is still important because severe insulin resistance, diabetes, hypertriglyceridemia, hypertension, and fatty liver increase atherosclerotic risk. A PPARG result should therefore direct attention to aggressive metabolic risk management rather than LMNA-style conduction disease surveillance unless the individual has separate cardiac findings.
Some PPARG variants are discovered during testing for severe insulin resistance or diabetes rather than visible lipodystrophy. This illustrates why the physical examination should include body-fat distribution when diabetes begins young, insulin requirements are high, and triglycerides or liver fat are out of proportion to BMI.
Families may contain carriers with different degrees of fat loss and metabolic disease. A mildly affected parent can have a child with more obvious FPLD3. The genotype identifies susceptibility, but it cannot forecast exact diabetes onset, triglyceride level, or need for insulin.
Who should consider genetic testing
Testing is appropriate when inherited partial lipodystrophy is clinically suspected. Features that raise suspicion include progressive loss of limb or gluteal subcutaneous fat, muscular appearance with central or facial fat accumulation, severe insulin resistance, diabetes at a young age, high insulin requirements, extreme triglycerides, recurrent pancreatitis, or fatty liver that seems disproportionate to overall obesity.
A family history strengthens the indication. Relatives may have a similar body shape, diabetes, high triglycerides, pancreatitis, fatty liver, early coronary disease, cardiomyopathy, pacemakers, or muscle disease. Because visible features can be subtle, clinicians should ask about photographs, clothing fit, and changes at puberty rather than only whether relatives were diagnosed with lipodystrophy.
Testing is also useful when a person labeled as having type 2 diabetes has a mismatch between BMI and metabolic severity. A lean or muscular individual with marked insulin resistance should not be assumed to have ordinary type 2 diabetes. Conversely, a person with central adiposity can still have peripheral lipoatrophy.
The most clearly affected living relative should be tested first. A curated lipodystrophy panel commonly includes LMNA, PPARG, PLIN1, CIDEC, AKT2, LIPE, and other genes selected for the distribution, age at onset, and inheritance. Broader genes are needed when generalized fat loss, congenital onset, developmental abnormalities, muscle disease, or progeroid features are present.
A single-gene LMNA test may be reasonable for a classic Dunnigan phenotype with a known familial variant. A focused PPARG test may be selected in an established FPLD3 family. In a new index case, a panel often avoids anchoring on one phenotype because clinical overlap is substantial.
Testing should be performed with pretest counseling. Possible results include a pathogenic variant, no molecular diagnosis, a VUS, or a finding with broader implications. LMNA results can reveal cardiac or neuromuscular risk that the patient did not anticipate. Families should understand inheritance, variable expression, and the implications for children.
A negative test does not exclude FPLD. Many clinically diagnosed partial lipodystrophy cases remain molecularly unresolved, and some may have polygenic or acquired causes. Metabolic treatment should not be withheld while genetic evaluation is incomplete.
How the test and results work
Testing usually uses blood or saliva and does not require fasting. The laboratory sequences the selected genes and may analyze exon-level deletions and duplications. The report should state coverage, transcripts, copy-number methods, and any regions with reduced sensitivity.
A pathogenic or likely pathogenic variant that fits the phenotype confirms a molecular subtype. An LMNA result should be interpreted with laminopathy-specific evidence and the variant’s known disease associations. A PPARG result should be assessed for loss-of-function or dominant-negative effects compatible with FPLD3. The same five-tier terms—pathogenic, likely pathogenic, uncertain significance, likely benign, and benign—apply, but evidence differs by gene.
A positive result can explain the metabolic phenotype and enable targeted testing of relatives. It does not measure current insulin resistance, liver fibrosis, triglyceride-related pancreatitis risk, or cardiac status. Those require clinical tests. It also does not predict the exact severity in a child who inherits the variant.
A negative result means no reportable cause was found with the assay. The person may still meet clinical criteria for FPLD. The gene may be unknown, the variant may lie outside tested regions, or the phenotype may be acquired or multifactorial. Periodic reanalysis or broader sequencing may be considered when suspicion remains strong.
A VUS should not establish the diagnosis, be used for predictive testing of healthy relatives, or determine reproductive decisions. Family studies may help when multiple relatives have well-characterized fat distribution and metabolic findings, but they should be planned by genetics professionals. A practical explanation is available in the guide to pathogenic, benign, and uncertain genetic results.
Likely benign and benign variants do not explain lipodystrophy. An unrelated pathogenic finding from exome or genome sequencing should be handled separately. The laboratory classification date matters because variant knowledge evolves.
Post-test counseling translates the result into a surveillance plan. The plan should list metabolic tests, liver assessment, pancreatitis prevention, cardiovascular evaluation, and LMNA-specific cardiac or muscle care when relevant. The written plan is more useful than the gene name alone.
Metabolic and cardiac evaluation
At diagnosis, evaluation generally includes fasting glucose, hemoglobin A1c, fasting lipids, liver enzymes, blood pressure, kidney function, and urine albumin. Triglycerides require particular attention because severe elevation can trigger pancreatitis. A history of abdominal pain, prior pancreatitis, alcohol, and medicines that raise triglycerides helps estimate risk.
Liver assessment may include ultrasound, elastography, or MRI-based fat and fibrosis evaluation. Normal liver enzymes do not exclude steatosis or fibrosis. Referral to hepatology is appropriate when fibrosis, inflammation, portal hypertension, or uncertain liver disease is present.
Diabetes assessment goes beyond glucose level. Insulin dose, C-peptide when relevant, hypoglycemia, and other complications guide treatment. Eye, kidney, nerve, and foot screening follow diabetes standards, often beginning earlier because metabolic disease may be severe.
Reproductive assessment can address menstrual irregularity, hyperandrogenism, fertility, and pregnancy history. Polycystic ovary syndrome can be part of the phenotype, but common PCOS without lipoatrophy is not FPLD. Pregnancy may worsen triglycerides and insulin resistance, so preconception planning is important.
Cardiovascular evaluation includes smoking status, blood pressure, lipid profile, family premature coronary disease, and symptoms. Coronary risk may be high even in young adults. Lipoprotein(a) measurement can identify an additional inherited risk factor.
After an LMNA pathogenic variant, baseline ECG and echocardiography are reasonable. Ambulatory rhythm monitoring or cardiac magnetic resonance may be added when conduction abnormalities, palpitations, syncope, ventricular dysfunction, or a family cardiac history is present. Follow-up intervals depend on variant and phenotype. A PPARG result generally does not require the same laminopathy surveillance unless clinical findings independently justify it.
Body composition can be documented with DXA or MRI when diagnosis or progression is uncertain. These tests should support, not replace, physical examination and metabolic assessment. Leptin concentration may be measured in specialized care, but no single cutoff diagnoses partial lipodystrophy or predicts treatment response.
Treatment and daily management
Nutrition aims to reduce ectopic fat and triglyceride production without causing malnutrition. A balanced eating pattern limits refined carbohydrate, sugar-sweetened beverages, and excess saturated fat. When triglycerides are extremely high, a very-low-fat plan may be temporarily or chronically necessary under dietitian supervision. Alcohol can sharply increase triglycerides and pancreatitis risk and may need to be avoided.
Regular physical activity improves insulin sensitivity and cardiovascular health, but recommendations are individualized for people with LMNA-related cardiomyopathy, muscle weakness, or severe metabolic complications. Exercise does not restore missing adipose tissue but can improve glucose handling and conditioning.
Metformin is often used for insulin resistance and diabetes. Additional glucose-lowering therapies are selected according to kidney function, liver disease, weight, cardiovascular risk, and evidence in lipodystrophy. Insulin may be required in high doses. Concentrated formulations or pumps can reduce injection burden for selected patients.
Triglyceride treatment can include fibrates, prescription omega-3 fatty acids, strict glycemic control, and dietary intervention. Statins are used to reduce atherosclerotic risk and non-HDL cholesterol, often in combination with other lipid-lowering therapy. Acute pancreatitis requires urgent hospital care.
Metreleptin can improve metabolic abnormalities in generalized lipodystrophy and selected patients with partial lipodystrophy who have severe complications and low leptin, depending on regulatory approval and access. Response is variable in partial forms. It is a specialized therapy with monitoring for immune and hematologic concerns and should not be viewed as routine cosmetic treatment.
Thiazolidinediones may help some PPARG-related or other partial lipodystrophy patients, but evidence is limited and adverse effects matter. Fluid retention can be hazardous in heart failure. Decisions require an endocrinologist familiar with the subtype.
Cosmetic and psychological concerns are legitimate aspects of care. Facial fat accumulation, limb lipoatrophy, muscular appearance, and social misunderstanding can affect self-esteem and relationships. Reconstructive or cosmetic procedures may be considered, but metabolic stabilization and realistic expectations are important. Mental health support can help with stigma and chronic disease burden.
Family screening and reproductive planning
Most LMNA-related FPLD2 and PPARG-related FPLD3 are autosomal dominant. Each child, sibling, or parent of a carrier has a 50% chance of carrying the familial variant. Because expression varies, a relative may have diabetes or high triglycerides without obvious lipoatrophy.
Targeted testing is offered after a pathogenic familial variant is identified. Positive relatives receive a baseline body-composition examination, glucose and lipid testing, liver evaluation, and subtype-specific surveillance. For LMNA carriers, cardiac review is added according to the variant and family phenotype. Negative relatives can usually avoid repeated FPLD-specific testing.
If the index patient’s panel is negative, relatives are evaluated clinically. Historical photographs, body-fat pattern, fasting lipids, glucose, liver findings, and reproductive history may identify others who need specialist assessment. A normal BMI does not exclude disease.
Testing children can be appropriate because metabolic abnormalities may emerge around puberty and early intervention can reduce complications. The timing should reflect the familial age of onset and whether results will change monitoring. Children should not be subjected to unnecessary dieting based on appearance alone.
A VUS should not be used to label a healthy relative. Clinical screening continues while the variant is reassessed. Testing clearly affected relatives can sometimes provide useful segregation evidence, but the laboratory should guide the strategy.
Adults with a confirmed variant can discuss reproductive options. Each pregnancy has a 50% transmission chance in typical autosomal dominant disease, but phenotype severity cannot be predicted precisely. Options include natural conception, prenatal diagnosis, and preimplantation genetic testing. Pregnancy also requires metabolic planning because triglycerides and glucose control may worsen.
Family communication should include the exact gene and variant, not merely “lipodystrophy.” A written family letter can explain the visible and metabolic features, inheritance, and route to testing. Early identification allows surveillance before diabetes, pancreatitis, advanced fatty liver, or cardiovascular disease develops.
References
- Clinical Guidance for Lipodystrophy Syndromes: From Diagnosis and Work-Up to Treatment (2025 Clinical Guidance)
- Lipodystrophy Syndromes: Presentation and Treatment (2024 Endotext)
- Clinical Spectrum of LMNA-Associated Type 2 Familial Partial Lipodystrophy: A Systematic Review (2023 Systematic Review)
- Familial partial lipodystrophy resulting from loss-of-function PPARγ pathogenic variants: phenotypic, clinical, and genetic features (2024 Review)
- Familial Partial Lipodystrophy—Literature Review and Report of a Novel Variant in PPARG Expanding the Spectrum of Disease-Causing Alterations in FPLD3 (2022 Review)
Disclaimer
This article provides general education and is not a substitute for evaluation by an endocrinologist, lipid specialist, cardiologist, hepatologist, dietitian, or genetics professional. Genetic results must be interpreted with body-fat distribution, metabolic tests, liver assessment, cardiac findings, and the exact variant. Severe abdominal pain, vomiting, chest pain, fainting, or symptoms of diabetic crisis require urgent medical care.
