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This not known with certainty but is estimated to be about one per million. It appears to be more common in females than males.
Lipodystrophy can be caused by metabolic abnormalities due to genetic issues. These are often characterized by insulin resistance and are associated with metabolic syndrome.
Around 250 cases have been reported since the recognition of this syndrome. It is a rare syndrome with no known prevalence, although it is more common than the generalized form of acquired lipodystrophy (Lawrence syndrome).
- Race: No clear relationship exists between incidence and race in this syndrome; however, most reported patients have been of European descent.
- Age: The median age of onset of lipodystrophy has been reported to be around seven years; however, onset occurring as late as the fourth or fifth decade of life also has been reported. The median age at presentation has been about 25 years, and women have been found to present later than men (age 28 for women, age 18 for men).
- Sex: Analysis of the pooled data revealed female patients were affected about four times more often than males.
A mutations in a number of genes have been associated with this condition. Mutations associated with FPL have been reported in "LMNA" (lamin A/C), "PPARG" (PPARγ), "AKT2" (AKT serine/threonine kinase 2), "PLIN1" (perilipin-1), and "CIDEC" (cell-death-inducing DFFA-like effector B).
Six types (1-6) have been described. Types 1-5 are inherited in an autosomal dominant fashion.
Type 1 (Kobberling variety, FPL1) is very rare and has only been reported in women to date. Fat loss is confined to the limbs and mostly in the distal parts. Central obesity may be present. Complications include hypertension, insulin resistance and hypertriglyceridemia. The gene causing this condition is not yet known. This form was first described in 1975.
Type 2 (Dunnigan Variety, FPL2) is the most common form and is due to mutations in the LMNA gene. Over 500 cases have been reported to date. Development up to puberty is normal. Fat is then gradually lost in is the limbs and trunk. Fat may accumulate around the face and between the shoulder blades. Insulin resistance is common. Other conditions associated with this condition include acanthosis nigricans, fatty liver, hypertriglyceridemia and polycystic ovary syndrome in women. There is an increased risk of coronary heart disease. Cardiomyopathy and muscular dystrophy may occur rarely. Xanthoma and nail changes may occur.
Type 3 is due to mutations in the PPARG gene. It is rare with approximately 30 cases reported to date. It is similar to type 2 but tends to be milder.
Type 4 is due to mutations in the PLIN1 gene. It is rare with only a small number of cases reported. Fat loss tends to affect the lower limbs and buttocks. Insulin resistance and hypertriglyceridemia occur. Calf muscular hypertrophy may occur.
Type 5 is due to mutations in the AKT2 gene. It has been reported in four patients all members of the same family. Fat loss affects the upper and lower limbs. The patients also suffered from hypertension, insulin resistance and hypertriglyceridemia.
Type 6 due to mutations in the CIDEC gene. It is inherited in an autosomal recessive fashion and has been reported in only one patient to date. Features included fat loss, severe insulin resistance, fatty liver, acanthosis nigricans and diabetes.
AGL with autoimmune origin is responsible for about 25% of all AGL reports. Those with autoimmune origin stems from other autoimmune diseases, most commonly with juvenile dermatomyositis and autoimmune hepatitis, but also occurs with rheumatoid arthritis, systemic lupus erythematous, and Sjogren syndrome.
About 25% of previously reported AGL is associated with panniculitis. Panniculitis is an inflammatory nodules of the subcutaneous fat, and in this type of AGL, adipose destruction originates locally at the infection or inflammation site and develops into generalized lipodystrophy.
Estimating the mortality rate based on the available literature is difficult. Several case reports have revealed an association between acquired partial lipodystrophy and other diseases.
Nephropathy, in the form of membranoproliferative glomerulonephritis, occurs in about 20% of patients. Usually, patients do not have clinically evident renal disease or abnormalities in renal function until they have had the disease for 8 or more years. Membranoproliferative glomerulonephritis usually presents with asymptomatic proteinuria or hematuria.
The disease may gradually progress. About 40-50% of patients develop end-stage renal disease over the course of 10 years. This condition is responsible for most recurrent hospital admissions in patients with acquired partial lipodystrophy. Rapid progression of renal disease in a pregnant patient was reported. Recurrent disease in transplanted kidneys is common, although there have been reports of successful transplantations.
Associated autoimmune diseases (e.g., systemic lupus erythematosus, thyroiditis) contribute significantly to increased morbidity in these patients compared with the general population. Although uncommon, insulin resistance increases cardiovascular risk. Susceptibility to bacterial infections probably results from a C3 deficiency (due to complement activation and consumption of C3). Low C3 levels may impair complement-mediated phagocytosis and bacterial killing.
Congenital generalized lipodystrophy (also known as Berardinelli–Seip syndrome) is an extremely rare autosomal recessive skin condition, characterized by an extreme scarcity of fat in the subcutaneous tissues. It is a type of lipodystophy disorder where the magnitude of fat loss determines the severity of metabolic complications. Only 250 cases of the condition have been reported, and it is estimated that it occurs in 1 in 10 million people worldwide.
The exact mechanism of HIV-associated lipodystrophy is not fully elucidated. There is evidence indicating both that it can be caused by anti-retroviral medications and that it can be caused by HIV infection in the absence of anti-retroviral medication.
Marfanoid–progeroid–lipodystrophy syndrome (MPL), also known as Marfan lipodystrophy syndrome (MFLS) or progeroid fibrillinopathy, is an extremely rare medical condition which manifests as a variety of symptoms including those usually associated with Marfan syndrome, an appearance resembling that seen in neonatal progeroid syndrome (NPS; also known as Wiedemann–Rautenstrauch syndrome), and severe partial lipodystrophy. It is a genetic condition that is caused by mutations in the "FBN1" gene, which encodes profibrillin, and affects the cleavage products of profibrillin, fibrillin-1, a fibrous structural protein, and asprosin, a glucogenic protein hormone. As of 2016, fewer than 10 cases of the condition have been reported. Lizzie Velasquez and Abby Solomon have become known publicly through the media for having the condition.
In addition to severe lipodystrophy (loss of adipose tissue), individuals with MPL show a concomitant marked loss of lean tissue mass, which also contributes to their "skinny" appearance. Based on visual inspection, it was originally thought that the lipodystrophy associated with MPL was generalized. However, it appears in fact to be partial, being confined to the face, distal extremities, and the and lateral regions of the buttocks. Normal amounts of subcutaneous fat are found in the torso over the chest and abdomen. As such, the breasts are normal in females with MPL.
Individuals with MPL have an appearance of being prematurely aged, but this is not due to actual early aging and is instead due to their paucity of subcutaneous fat. As such, MPL is not truly a form of progeria.
In 2016, it was discovered that the partial lipodystrophy associated with MPL is caused by loss of the C-terminal domain cleavage product of profibrillin and novel glucogenic protein hormone, which has been named asprosin. Due to asprosin deficiency, individuals with MPL eat less, and do not gain weight or develop symptoms of diabetes like insulin resistance. MPL patients burn less energy than normal individuals, but also consume less, and their net energy balance is moderately reduced. In contrast to MPL patients, whose asprosin is undetectable in the blood, individuals with obesity and diabetes have elevated levels of asprosin. As such, "FBN1" has been nicknamed the "thin gene", and drug development for targeted inhibition of asprosin signaling is considered to be an "unusually promising" potential therapeutic route in the treatment of obesity and diabetes.
Lipodystrophies can be a possible side effect of antiretroviral drugs. Other lipodystrophies manifest as lipid redistribution, with excess, or lack of, fat in various regions of the body. These include, but are not limited to, having sunken cheeks and/or "humps" on the back or back of the neck (also referred to as buffalo hump) which also exhibits due to excess cortisol. Lipoatrophy is most commonly seen in patients treated with thymidine analogue nucleoside reverse transcriptase inhibitors like zidovudine (AZT) and stavudine (d4T).
On the other hand, there is evidence that HIV-1 infection on its own contributes to the development of the lipodystrophic phenotype by interfering with some key genes of adipocyte differentiation and mitochondrial function on patients which have not received antiretroviral treatment.
There are differences in how Type 1 vs Type 2 patients are affected by the disease. In type 1 patients, they still have mechanical adipose tissue, but type 2 patients do not have any adipose tissue, including mechanical. In type 2 patients, there is a greater likelihood of psychomotor retardation and intellectual impairment.
Dunnigan-type familial partial lipodystrophy, also known as FPLD Type II and abbreviated as (FPLD2), is a rare monogenic form of insulin resistance characterized by loss of subcutaneous fat from the extremities, trunk, and gluteal region. FPLD recapitulates the main metabolic attributes of the insulin resistance syndrome, including central obesity, hyperinsulinemia, glucose intolerance and diabetes usually type 2, dyslipidemia, hypertension, and early endpoints of atherosclerosis. It can also result in hepatic steatosis. FPLD results from mutations in LMNA gene, which is the gene that encodes nuclear lamins A and C.
Many people with MDP syndrome are high achievers intellectually following careers in law, medicine and computing. A crucial point is that they do not have progeria and there is no evidence of accelerated intellectual decline with age in these patients. Equally life expectancy has not been shown to be reduced. Patients of 65 have been described in the literature and none of the patients are known to have malignancy. Therefore, there are many crucial differences with progeria and the name of progeroid in the title is confusing as this really refers to the lack of fat in the face and taut skin and not any intellectual or other age associated features.
Unlike other autoinflammatory disorders, patients with CANDLE do not respond to IL-1 inhibition treatment in order to stop the autoinflammatory response altogether. This suggests that the condition also involves IFN dysregulation.
Initially all people that have been identified with this syndrome have an identical genetic change, an inframe single codon deletion in POLD1 resulting in a loss of serine at position 605. The POLD1 gene is expressed in all cells and the particular change seen in most patients results in loss of DNA polymerase activity but only mildly impairs the proof reading exonuclease activity. In 2014 a second genetic change was reported in an Italian patient, a novel heterozygous mutation in exon 13 (R507C).
Most cases identified to date have been caused by a spontaneous genetic change (so the parents of the individual are unaffected).
Renal failure is the major cause of morbidity and mortality in complete LCAT deficiency, while in partial deficiency (fish eye disease) major cause of morbidity is visual impairment due to corneal opacity. These patients have low HDL cholesterol but surprisingly premature atherosclerosis is not seen. However, there are some reported cases.
Screening among family members of people with known FH is cost-effective. Other strategies such as universal screening at the age of 16 were suggested in 2001. The latter approach may however be less cost-effective in the short term. Screening at an age lower than 16 was thought likely to lead to an unacceptably high rate of false positives.
A 2007 meta-analysis found that "the proposed strategy of screening children and parents for familial hypercholesterolaemia could have considerable impact in preventing the medical consequences of this disorder in two generations simultaneously." "The use of total cholesterol alone may best discriminate between people with and without FH between the ages of 1 to 9 years."
Screening of toddlers has been suggested, and results of a trial on 10,000 one-year-olds were published in 2016. Work was needed to find whether screening was cost-effective, and acceptable to families.
Familial dysautonomia is seen almost exclusively in Ashkenazi Jews and is inherited in an autosomal recessive fashion. Both parents must be carriers in order for a child to be affected. The carrier frequency in Jewish individuals of Eastern European (Ashkenazi) ancestry is about 1/30, while the carrier frequency in non-Jewish individuals is unknown. If both parents are carriers, there is a one in four, or 25%, chance with each pregnancy for an affected child. Genetic counseling and genetic testing is recommended for families who may be carriers of familial dysautonomia.
Worldwide, there have been approximately 600 diagnoses recorded since discovery of the disease, with approximately 350 of them still living.
The most common known cause of the syndrome are mutations in the Proteasome Subunit, Beta Type, 8 (PSMB8) gene that codes for proteasomes that in turn break down other proteins. This occurs specifically when a mutation causes the homozygous recessive form to emerge. The mutated gene results in proteins not being degraded and oxidative proteins building up in cellular tissues, eventually leading to apoptosis, especially in muscle and fat cells.
A study conducted by Brehm et al. in November 2015 discovered additional mutations that can cause CANDLE syndrome, including PSMA3 (encodes α7), PSMB4 (encodes β7), PSMB9 (encodes β1i), and the proteasome maturation protein (POMP), with 8 mutations in total between them. An additional unknown mutation type in the original PSMB8 gene was also noted.
Cantu syndrome apparently is inherited in an autosomal dominant fashion and appears to be affected by the "ABCC9" gene
Centrifugal abdominal lipodystrophy (also known as "Centrifugal lipodystrophy," "Lipodystrophia centrifugalis abdominalis infantalis") is a skin condition characterized by areas of subcutaneous fat loss that slowly enlarge.
Cantú syndrome (hypertrychotic osteochondrodysplasia) is a rare condition characterized by hypertrichosis, osteochondrodysplasia, and cardiomegaly. Less than 50 cases have been described in the literature; they are associated with a mutation in the "ABCC9"-gene that codes for the ABCC9-protein.
Wiedemann–Rautenstrauch (WR) syndrome , also known as neonatal progeroid syndrome, is an autosomal recessive progeroid syndrome.
WR was first reported by Rautenstrauch and Snigula in 1977; and the earliest reports made subsequently have been by Wiedemann in 1979, by Devos in 1981, and Rudin in 1988. There have been over 30 cases of WR.
WR is associated with abnormalities in bone maturation, and lipids and hormone metabolism. Affected individuals exhibit intrauterine and postnatal growth retardation, leading to short stature and an aged appearance from birth. They have physical abnormalities including a large head (macrocephaly), sparse hair, prominent scalp veins, inward-folded eyelid (entropion), widened anterior fontanelles, hollow cheeks (malar hypoplasia), general loss of fat tissues under the skin (lipoatrophy), delayed tooth eruption, abnormal hair pattern (hypotrichosis), beaked nose, mild to severe mental retardation and dysmorphism.
Marfan lipodystrophy syndrome (MFLS) has sometimes been confused with Wiedemann–Rautenstrauch syndrome, since the Marfanoid features are progressive and sometimes incomplete. MFLS is caused by mutations near the 3'-terminus of "FBN1" that cause a deficiency of the protein hormone asprosin and progeroid-like symptoms with reduced subcutaneous white adipose tissue.