Diagnosis
A clinical reference on the recognition, evaluation, and subtype classification of lipodystrophy syndromes — including diagnostic criteria, genetic workup, and differential diagnosis. A companion patient-facing version is available separately.
Quick Facts & References
ICD-10 codes
Estimated prevalence
Key specialist resources
Approved therapy
Lipodystrophy: Pathophysiology and clinical significance
Lipodystrophy syndromes comprise a heterogeneous group of rare genetic or acquired disorders characterized by selective loss, deficiency, and/or dysfunction of adipose tissue, which may be generalized or partial. Impaired adipose tissue storage capacity leads to ectopic lipid deposition in non-adipose organs, resulting in progressive and often severe metabolic complications, including insulin resistance, dyslipidemia, hepatic steatosis, and cardiovascular comorbidities, with consequent increased risks of morbidity and premature mortality.
Lipodystrophy remains substantially under-recognized; most patients accumulate significant metabolic morbidity prior to diagnosis.
Abnormal fat distribution
Generalized or partial loss of subcutaneous fat, often with prominent muscles and veins in the arms and legs; acromegaloid or cushingoid appearance; fat sparing or excess in the face, neck, or abdomen in partial lipodystrophy.
Severe insulin resistance
Diabetes that may require high dose insulin, acanthosis nigricans, PMOS or oligomenorrhoea in women.
Dyslipidemia
Hypertriglyceridaemia (≥500 mg/dL, resistant to standard treatment); low HDL-cholesterol; history of acute pancreatitis.
Hepatic steatosis
Elevated liver enzymes; hepatomegaly on examination; ultrasound or CT findings consistent with MASLD in the absence of other identifiable cause.
Cardiovascular complications
Premature atherosclerosis; hypertrophic cardiomyopathy, arrhythmias and conduction defects.
For the full clinical signs and symptoms reference — including organ-by-organ breakdown, frequency data by subtype, and distinguishing features — see the dedicated signs and symptoms page.
How lipodystrophy is evaluated and confirmed
Diagnosis proceeds through two sequential phases: clinical recognition based on phenotypic features and metabolic profile, followed by subtype characterization through genetic and immunological testing. The clinical diagnosis can and should be made independently of genetic confirmation.
Mean diagnostic delay was 7.4 ± 8.1 years for generalized and 23.8 ± 17.1 years for partial lipodystrophy (Spanish cohort, n=140).
Phase 1
Clinical recognition and metabolic evaluation
The following assessments are conducted concurrently and constitute the basis for a clinical diagnosis:
01
Medical history and physical exam
Systematic assessment of adipose tissue distribution is central. Clinicians should examine for lipoatrophy in the face, limbs, and gluteal region, and for lipohypertrophy in the abdomen, dorso-cervical region (“buffalo hump”), and axillae. Cutaneous stigmata of insulin resistance – acanthosis nigricans, eruptive xanthomas – should be documented. Family history of similar phenotype, consanguinity, and age of symptom onset inform subtype classification.
02
Metabolic laboratory evaluation
Order a comprehensive fasting metabolic panel. The following tests are recommended as first-line evaluation in any patient with suspected lipodystrophy:
-
- Fasting lipid panel – TG, HDL-C, LDL-C, total cholesterol
- Fasting glucose, fasting insulin, HbA1c
- Liver function tests – ALT, AST, GGT, ALP
- Renal function – eGFR, urine albumin:creatinine ratio
- Urinalysis for proteinuria
- C3 and C4 complement (acquired forms)
- ANA, anti-dsDNA (suspected AGL)
- Leptin – Low leptin levels may support a diagnosis of lipodystrophy; however, normal or elevated leptin levels do not exclude the diagnosis. Leptin measurement may also help guide treatment decisions, including assessment of eligibility for leptin replacement therapy
Note: Other blood and urine tests may be needed per clinical indication
03
Body composition and liver imaging
Multiple imaging modalities are available to assess adipose tissue distribution. Choice depends on availability and clinical context; no single modality is required. Liver imaging should be ordered in all patients to evaluate for MASLD.
Body fat distribution:
-
- DXA Scan with regional fat analysis – limb vs trunk fat ratio
- Skinfold thickness measurement – triceps, biceps, subscapular, suprailiac, thigh, calf
Liver imaging for MASLD:
-
- Abdominal ultrasound – first-line liver assessment
- Hepatic MRI – quantification of hepatic fat fraction
- Transient elastography (FibroScan) – liver stiffness / fibrosis staging
- Liver biopsy – if NASH/fibrosis staging required
Understanding Lipodystrophy – A Primer for Hepatologists
04
Synthesis: establishing the clinical diagnosis
The diagnosis of lipodystrophy is based on the constellation of phenotypic features – characteristic fat distribution pattern, metabolic profile, and supportive imaging – in the absence of an alternative explanation. Importantly, genetic testing is used to confirm and classify the subtype, not to make the initial diagnosis. Initiating metabolic management, including referral for metreleptin therapy assessment, does not require genetic confirmation.
Phase 2
Subtype characterization and genetic evaluation
01
Genetic Testing
Next-generation sequencing (NGS) gene panel testing covering established lipodystrophy loci is the recommended first-line genetic investigation. Whole-exome sequencing (WES) or whole-genome sequencing (WGS) may be indicated when panel testing is uninformative but clinical suspicion remains high. Variants of uncertain significance (VUS) require expert interpretation in the context of phenotype; co-segregation analysis in affected family members are often informative. A negative genetic result does not exclude lipodystrophy – pathogenic variants are identified in only approximately 50–60% of clinically confirmed cases.
02
Acquired form workup
For AGL and APL, immunological evaluation is essential. AGL is frequently associated with autoimmune conditions – notably autoimmune hepatitis, dermatomyositis, and panniculitis – and autoantibody screening (ANA, anti-dsDNA, anti-C1q) is warranted. APL is associated with low C3 complement, C3 nephritic factor (C3NeF) in the majority of cases, and type II MPGN in approximately 30% of patients; renal function and urinary protein should be monitored regularly.
Referral and next steps
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- Referral to an endocrinologist with expertise in metabolic disease or a designated lipodystrophy center is recommended for all confirmed or suspected cases.
- Lipodystrophy often requires multidisciplinary management involving endocrinology, genetics, cardiology, hepatology, nutrition, mental health support and other relevant specialties. Clinicians should coordinate care across disciplines to support comprehensive evaluation, monitor metabolic and cardiovascular complications, and develop an individualized long-term management plan.
Genetic classification and inheritance
The monogenic lipodystrophies are caused by pathogenic variants in genes encoding proteins involved in adipogenesis, lipid droplet biology, nuclear envelope integrity, and adipokine signalling.
CGL type 1
CGL type 2
CGL type 3
CGL type 4
FPLD type 1
(Kobberling)
FPLD type 2 (Dunnigan)
FPLD type 3
FPLD type 4
FPLD type 5
AGL
APL
Variant interpretation and negative results
Approximately 40–50% of patients with a clinical lipodystrophy phenotype do not have an identifiable pathogenic or likely pathogenic variant on current panel testing. This likely reflects incomplete gene coverage, novel loci not yet characterized, and oligogenic contributions. A negative genetic test result does not exclude lipodystrophy and should not delay metabolic management.
Subtype:
CGL type 1
Gene(s):
AGPAT2
Inheritence:
Autosomal Recessive
Protein / pathway:
1-acylglycerol-3-phosphate O-acyltransferase 2; glycerophospholipid synthesis
Key features:
Mechanical and metabolic adipose tissue loss; sparing of palms/soles/orbits/scalp
Subtype:
CGL type 2
Gene(s):
BSCL2
Inheritence:
Autosomal Recessive
Protein / pathway:
Seipin; lipid droplet biogenesis and ER-lipid droplet contacts
Key features:
More severe phenotype; intellectual disability in ~50%; cardiac complications
Subtype:
CGL type 3
Gene(s):
CAV1
Inheritence:
Autosomal Recessive
Protein / pathway:
Caveolin-1; caveolae formation and lipid trafficking
Key features:
Rare; pulmonary hypertension; short stature
Subtype:
CGL type 4
Gene(s):
PTRF
Inheritence:
Autosomal Recessive
Protein / pathway:
Cavin-1; caveolae assembly and stability
Key features:
Rare; myopathy; rippling muscle disease; skeletal dysplasia
Subtype:
FPLD type 1 (Köbberling)
Gene(s):
No identified causative gene
Inheritence:
Unknown / polygenic
Protein / pathway:
Thought to be oligogenic/polygenic (multiple genes and modifiers) or to harbour undiscovered rare variants; precise mechanism unknown
Key features:
Loss of limb fat with preserved facial and abdominal fat; diagnosis clinical; often excluded from registry analyses due to diagnostic uncertainty; more common in women with android obesity phenotype
FPLD type 1 (Köbberling syndrome) has no identified causative gene and is thought to be oligogenic or polygenic; it is excluded from some registry prevalence analyses due to diagnostic uncertainty.
Subtype:
FPLD type 2 (Dunnigan)
Gene(s):
LMNA
Inheritence:
Autosomal Dominant
Protein / pathway:
Lamin A/C; nuclear lamina integrity and mechanosignalling
Key features:
Most common FPLD; fat loss from limbs/trunk post-puberty; cardiac conduction defects
Subtype:
FPLD type 3
Gene(s):
PPARG
Inheritence:
Autosomal Dominant
Protein / pathway:
Peroxisome proliferator-activated receptor γ; master regulator of adipogenesis
Key features:
Variable expressivity; severe hypertriglyceridaemia; often misclassified as T2DM
Subtype:
FPLD type 4
Gene(s):
PLIN1
Inheritence:
Autosomal Dominant
Protein / pathway:
Perilipin-1; lipid droplet coat protein; lipolysis regulation
Key features:
Rare; prominent limb fat loss; severe metabolic disease
Subtype:
FPLD type 5
Gene(s):
CIDEC
Inheritence:
Autosomal Recessive
Protein / pathway:
Cell death-inducing DFFA-like effector C; lipid droplet fusion
Key features:
Rare; generalised phenotype in some reports
Subtype:
AGL
Gene(s):
No single gene
Inheritence:
Acquired
Protein / pathway:
Autoimmune destruction of adipocytes; complement dysregulation
Key features:
Panniculitis in ~25%; associated autoimmune disorders; genetic testing uninformative
Subtype:
APL
Gene(s):
LIPE (rare)
Inheritence:
Acquired
Protein / pathway:
Complement C3 dysregulation via C3NeF; C3 nephritic factor-mediated adipocyte lysis
Key features:
Cranio-caudal progression; MPGN in ~30%; low C3, normal C4
The 4 main subtypes — clinical profiles
The four recognized primary subtypes differ substantially in phenotypic severity, metabolic profile, associated comorbidities, and treatment response. Identifying the correct subtype informs both the immediate management plan and long-term surveillance.
01
Congenital Generalized Lipodystrophy (CGL)
AKA: Berardinelli-Seip Congenital Lipodystrophy (BSCL)
Near-complete absence of metabolic and mechanical adipose tissue from birth, resulting in severe hypoleptinemia, extreme insulin resistance, and progressive ectopic lipid deposition. Hepatomegaly, cardiomyopathy, and acromegaloid features are common. CGL2 (BSCL2) has a more severe phenotype including cognitive impairment and cardiac involvement.
Onset: Congenital; recognized at birth or in infancy
Genetics: AGPAT2, BSCL2, CAV1, PTRF — autosomal recessive
Leptin: Severely low (<1–2 ng/mL); eligible for metreleptin4
Key Risks: Hypertriglyceridaemia-induced pancreatitis; NASH/cirrhosis; cardiomyopathy
02
Familial Partial Lipodystrophy (FFLD)
Progressive lipoatrophy of the extremities and trunk beginning at puberty, with relative or absolute lipohypertrophy of the face, neck, and abdomen. Metabolic complications are severe but phenotypic expression is variable – particularly in FPLD3 (PPARG). Cardiac conduction defects and cardiomyopathy are important extraphenotypic features in FPLD2 (LMNA).
Onset: Peripubertal; more marked in females post-puberty
Genetics: LMNA, PPARG, PLIN1, AKT2 — autosomal dominant (most)
Leptin: Low-normal to low; metreleptin approved for GL; off-label use in FPLD in some jurisdictions
Key Risks: T2DM; severe hypertriglyceridaemia; PCOS-like phenotype; LMNA cardiac disease
03
Acquired Generalized Lipodystrophy
AKA: Lawrence Syndrome
Progressive generalized lipoatrophy developing in childhood or adolescence in a previously unaffected individual. In approximately 25% of cases, lipoatrophy follows a panniculitis episode. The remaining cases are associated with autoimmune conditions (autoimmune hepatitis, dermatomyositis, juvenile idiopathic arthritis). Metabolic phenotype resembles CGL.13
Onset: Childhood–adolescence; may follow panniculitis or systemic illness
Genetics: Not applicable; autoimmune etiology
Workup: ANA, anti-dsDNA, complement panel, liver biopsy if hepatitis suspected
Key Risks: Autoimmune hepatitis; severe metabolic disease; insulin resistance
04
Acquired Partial Lipodystrophy (APL)
AKA: Barraquer-Simons Syndrome
Cranio-caudal progression of lipoatrophy affecting the face, arms, and thorax, with paradoxical lipohypertrophy of the lower limbs in some patients. Pathogenesis involves C3 nephritic factor (C3NeF)-mediated continuous complement activation, leading to complement-dependent adipocyte lysis in adipsin-rich depots. Approximately 30% of patients develop MPGN.
Onset: Childhood–adolescence; F > M (~4:1)
Genetics: LIPE in rare familial cases; otherwise acquired
Workup: C3, C4, C3NeF; renal biopsy if MPGN suspected; eGFR monitoring
Key Risks: MPGN type II; end-stage renal disease; metabolic disease less severe than generalized forms
Unclassified and atypical lipodystrophy
A significant proportion of patients present with a phenotype consistent with lipodystrophy but do not carry a pathogenic variant in currently established loci. These patients should not be excluded from specialist management on this basis. Enrollment in registries and research studies is strongly encouraged.
Conditions in the differential — distinguishing features
Lipodystrophy is frequently misdiagnosed due to phenotypic overlap with common metabolic disorders. For each condition below: distinguishing features, mechanistic basis, and when to think about lipodystrophy.
Type 2 diabetes mellitus / metabolic syndrome
Obesity / common overweight
Polycystic ovary syndrome (PCOS)
Cushing’s Syndrome
Familial hypertriglyceridaemia / familial combined hyperlipidaemia
Anorexia nervosa / restrictive eating disorder
Type 2 diabetes mellitus / metabolic syndrome
The hyperglycaemia, dyslipidaemia, and hypertension in lipodystrophy are metabolically indistinguishable from T2DM at initial presentation. Patients are often managed for years with escalating antidiabetic therapy without adequate response.
Distinguishing features: Insulin resistance disproportionate to degree of adiposity; TG >500 mg/dL; low serum leptin; characteristic fat distribution on imaging.
Mechanistic basis: Ectopic lipid deposition in skeletal muscle and liver drives severe hepatic and peripheral insulin resistance independent of BMI — the core pathophysiology is distinct from obesity-driven T2DM.
Think lipodystrophy when: Diabetes is unresponsive to standard oral agents; insulin requirement ≥100–200 U/day with poor glycaemic control; HbA1c remains high despite maximal therapy; diagnosis made at young age or low BMI.
Obesity / common overweight
In FPLD, facial and abdominal lipohypertrophy combined with metabolic syndrome leads to an initial impression of simple obesity. The characteristic limb lipoatrophy is missed without systematic examination.
Distinguishing features: Reduced limb fat on DXA (<30% of total fat mass in limbs); metabolic disease disproportionate to BMI.
Mechanistic basis: Redistribution of adipose tissue — not true hyperphagia-driven expansion — accounts for the apparent obesity. Standard weight loss interventions do not improve the underlying lipodystrophic metabolic phenotype.
Think lipodystrophy when: Disproportionate fat accumulation in the face, neck, or abdomen with visible areas of lipoatrophy in the limbs or buttocks; marked metabolic disease inconsistent with degree of overweight; weight loss efforts fail to improve metabolic parameters.
Cushing’s syndrome
Central adiposity with metabolic complications in lipodystrophy overlaps with hypercortisolaemic phenotype, prompting extensive biochemical and imaging exclusion of cortisol excess before lipodystrophy is considered.
Distinguishing features: Normal 24-hour urinary free cortisol and overnight dexamethasone suppression test; absence of thin skin, proximal myopathy, and striae typical of Cushing’s; lipoatrophy of the extremities
Mechanistic basis: Both conditions cause central fat redistribution, but the peripheral lipoatrophy of lipodystrophy and normal cortisol axis distinguish them definitively.
Think lipodystrophy when: Multiple cortisol investigations are consistently normal; the patient has prominent limb lipoatrophy alongside abdominal fat — the opposite of the truncal distribution seen in Cushing’s; muscle hypertrophy or phlebomegaly is present in the limbs.
Polyendocrine metabolic ovary syndrome (PMOS)
Hyperinsulinaemia-driven hyperandrogenism in FPLD produces a clinical and biochemical phenotype indistinguishable from PMOS – oligomenorrhoea, elevated androgens.
Distinguishing features: TG markedly elevated beyond what PCOS alone produces; limb lipoatrophy on examination; family history consistent with AD inheritance; leptin low-normal
Mechanistic basis: The hyperandrogenism in lipodystrophy is secondary to severe hyperinsulinaemia, not a primary ovarian or adrenal process. Insulin sensitization is the correct treatment target.
Think lipodystrophy when: PMOS diagnosis coexists with severe hypertriglyceridaemia or extreme insulin resistance; standard PMOS treatments (metformin, OCP) produce inadequate response; limb fat appears reduced relative to facial or abdominal fat; strong family history of metabolic disease.
Familial hypertriglyceridaemia / familial combined hyperlipidaemia
Extreme hypertriglyceridaemia in lipodystrophy is treated as a primary dyslipidaemia without investigation of the underlying cause, particularly when the patient is not overtly lipoatrophic or lean.
Distinguishing features: TG persistently >500 mg/dL despite fibrate therapy; low serum leptin; associated insulin resistance exceeding what primary dyslipidaemia produces; fat distribution abnormality on DXA/MRI
Mechanistic basis: Impaired triglyceride storage in absent/deficient adipose tissue forces excess circulating VLDL and chylomicrons — the hypertriglyceridaemia is secondary and requires treatment of the underlying adipose deficiency.
Think lipodystrophy when: Hypertriglyceridaemia is refractory to fibrate therapy or recurs rapidly after pancreatitis; TG >1,000 mg/dL in a young or non-obese patient; hypertriglyceridaemia is accompanied by severe insulin resistance or hepatic steatosis without another identifiable cause.
Anorexia nervosa / restrictive eating disorder
The pronounced lipoatrophy and apparent leanness of generalized forms — particularly in paediatric patients — is misattributed to caloric restriction. Paradoxically, leptin deficiency produces hyperphagia, not anorexia.
Distinguishing features: Hyperphagia (not restriction); metabolic disease inconsistent with malnutrition (elevated TG, hyperinsulinaemia); muscular, acromegaloid appearance; very low leptin
Mechanistic basis: Absolute leptin deficiency eliminates leptin-mediated satiety signalling, producing persistent hyperphagia. The lean phenotype reflects absent adipose tissue, not nutritional deprivation — serum albumin and micronutrient status are typically normal.
Think lipodystrophy when: A lean or muscular patient reports extreme hunger or hyperphagia rather than restriction; metabolic labs show hyperinsulinaemia, elevated TG, or fatty liver — findings inconsistent with starvation; serum albumin and micronutrients are normal despite the lean appearance.
Clinical pearl: when to suspect lipodystrophy
Consider lipodystrophy evaluation in any patient with:
(1) Fasting TG >500 mg/dL without secondary cause
(2) Insulin requirement >200 units/day
(3) Metabolic syndrome with abnormal fat distribution
(4) PMOS-phenotype with severe hypertriglyceridaemia
(5) Family history of unexplained severe metabolic disease
Key literature
The clinical content on this page is informed by peer-reviewed literature in lipodystrophy diagnosis, classification, and management. The full reference list — including all cited works and additional reading — is available on the dedicated bibliography page.
Clinical Signs
Does my patient have Lipodystrophy?
Here’s what to look for.
Researchers & Clinicians
Home base for up-to-date clinical information regarding lipodystrophies.
Therapies
What treatments are available for lipodystrophy?
Symptom Management
Many patients manage symptoms with their lifestyle and diet. Learn how they do it.
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