CLOVES syndrome is a rare overgrowth syndrome with complex vascular anomalies. CLOVES syndrome affects people with various symptoms, ranging from mild fatty soft-tissue tumors to vascular malformations encompassing the spine or internal organs.
It is a genetic disorder that results from somatic, mosaic gain-of-function mutations of the PIK3CA gene, and belongs to the spectrum of PIK3CA-related overgrowth syndromes (PROS). This rare condition has no specific treatment and a poor survival rate.
French doctor Guillaume Canaud [1] published an article in Nature that demonstrate the efficacy of BYL719 (From cancer), an inhibitor of PIK3CA, in preventing and improving organ dysfunction. It seems this treatment is having tremendous and quick effects.
CLOVES syndrome is closely linked to other overgrowth disorders like proteus syndrome, Klippel–Trénaunay syndrome, Sturge–Weber syndrome, and hemihypertrophy, to name a few.
'CLOVES' is an acronym for: [2] [3]
The syndrome was first recognised by Saap and colleagues who recognised the spectrum of symptoms from a set of seven patients. [4] In this initial description the syndrome is named CLOVE syndrome. It is believed that the first description of a case of CLOVES syndrome was written by Hermann Friedberg, a German physician, in 1867. [5] [6]
Somatic mutations in the PIK3CA have been identified as a cause of CLOVES syndrome. [7] PIK3CA is a protein involved in the PI3K-AKT signalling pathway. Mutations in other parts of this pathway cause other overgrowth syndromes including Proteus syndrome and hemimegaencephaly. [7]
Arteriovenous malformation is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system, but can appear in any location. Although many AVMs are asymptomatic, they can cause intense pain or bleeding or lead to other serious medical problems.
Megalencephaly is a growth development disorder in which the brain is abnormally large. It is characterized by a brain with an average weight that is 2.5 standard deviations above the mean of the general population. Approximately 1 out of 50 children (2%) are said to have the characteristics of megalencephaly in the general population.
Proteus syndrome is a rare disorder with a genetic background that can cause tissue overgrowth involving all three embryonic lineages. Patients with Proteus syndrome tend to have an increased risk of embryonic tumor development. The clinical and radiographic symptoms of Proteus syndrome are highly variable, as are its orthopedic manifestations.
Hereditary hemorrhagic telangiectasia (HHT), also known as Osler–Weber–Rendu disease and Osler–Weber–Rendu syndrome, is a rare autosomal dominant genetic disorder that leads to abnormal blood vessel formation in the skin, mucous membranes, and often in organs such as the lungs, liver, and brain.
Lymphangiomas are malformations of the lymphatic system characterized by lesions that are thin-walled cysts; these cysts can be macroscopic, as in a cystic hygroma, or microscopic. The lymphatic system is the network of vessels responsible for returning to the venous system excess fluid from tissues as well as the lymph nodes that filter this fluid for signs of pathogens. These malformations can occur at any age and may involve any part of the body, but 90% occur in children less than 2 years of age and involve the head and neck. These malformations are either congenital or acquired. Congenital lymphangiomas are often associated with chromosomal abnormalities such as Turner syndrome, although they can also exist in isolation. Lymphangiomas are commonly diagnosed before birth using fetal ultrasonography. Acquired lymphangiomas may result from trauma, inflammation, or lymphatic obstruction.
The phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha, also called p110α protein, is a class I PI 3-kinase catalytic subunit. The human p110α protein is encoded by the PIK3CA gene.
A vascular malformation is a blood vessel or lymph vessel abnormality. Vascular malformations are one of the classifications of vascular anomalies, the other grouping is vascular tumors. They may cause aesthetic problems as they have a growth cycle, and can continue to grow throughout life.
Vascular myelopathy refers to an abnormality of the spinal cord in regard to its blood supply. The blood supply is complicated and supplied by two major vessel groups: the posterior spinal arteries and the anterior spinal arteries—of which the Artery of Adamkiewicz is the largest. Both the posterior and anterior spinal arteries run the entire length of the spinal cord and receive anastomotic (conjoined) vessels in many places. The anterior spinal artery has a less efficient supply of blood and is therefore more susceptible to vascular disease. Whilst atherosclerosis of spinal arteries is rare, necrosis in the anterior artery can be caused by disease in vessels originating from the segmental arteries such as atheroma or aortic dissection.
Congenital hemidysplasia with ichthyosiform erythroderma and limb defects is a genetic disorder with onset at birth seen almost exclusively in females. The disorder is related to CPDX2, and also has skin and skeletal abnormalities, distinguished by a sharp midline demarcation of the ichthyosis with minimal linear or segmental contralateral involvement.
Cobb syndrome is a rare congenital disorder characterized by visible skin lesions with underlying spinal angiomas or arteriovenous malformations (AVMs). The skin lesions of Cobb syndrome typically are present as port wine stains or angiomas, but reports exist of angiokeratomas, angiolipomas, and lymphangioma circumscriptum. The intraspinal lesions may be angiomas or AVMs and occur at levels of the spinal cord corresponding to the affected skin dermatomes. They may in turn produce spinal cord dysfunction and weakness or paralysis.
Klippel–Trénaunay syndrome, formerly Klippel–Trénaunay–Weber syndrome and sometimes angioosteohypertrophy syndrome and hemangiectatic hypertrophy, is a rare congenital medical condition in which blood vessels and/or lymph vessels fail to form properly. The three main features are nevus flammeus, venous and lymphatic malformations, and soft-tissue hypertrophy of the affected limb. It is similar to, though distinctly separate from, the less common Parkes Weber syndrome.
Bonnet–Dechaume–Blanc syndrome, also known as Wyburn-Mason syndrome, is a rare congenital disorder characterized by arteriovenous malformations of the brain, retina or facial nevi. The syndrome has a number of possible symptoms and can, more rarely, affect the skin, bones, kidneys, muscles, and gastrointestinal tract. When the syndrome affects the brain, people can experience severe headaches, seizures, acute stroke, meningism, and progressive neurological deficits due to acute or chronic ischaemia caused by arteriovenous shunting.
Blue rubber bleb nevus syndrome is a rare disorder that consists mainly of abnormal blood vessels affecting the skin or internal organs – usually the gastrointestinal tract. The disease is characterized by the presence of fluid-filled blisters (blebs) as visible, circumscribed, chronic lesions (nevi).
A vascular anomaly is any of a range of lesions from a simple birthmark to a large tumor that may be disfiguring. They are caused by a disorder of the vascular system. A vascular anomaly is a localized defect in blood or lymph vessels. These defects are characterized by an increased number of vessels, and vessels that are both enlarged and sinuous. Some vascular anomalies are congenital, others appear within weeks to years after birth, and others are acquired by trauma or during pregnancy. Inherited vascular anomalies are also described and often present with a number of lesions that increase with age. Vascular anomalies can also be a part of a syndrome.
Parkes Weber syndrome (PWS) is a congenital disorder of the vascular system. It is an extremely rare condition, and its exact prevalence is unknown. It is named after British dermatologist Frederick Parkes Weber, who first described the syndrome in 1907.
Macrocephaly-capillary malformation (M-CM) is a multiple malformation syndrome causing abnormal body and head overgrowth and cutaneous, vascular, neurologic, and limb abnormalities. Though not every patient has all features, commonly found signs include macrocephaly, congenital macrosomia, extensive cutaneous capillary malformation, body asymmetry, polydactyly or syndactyly of the hands and feet, lax joints, doughy skin, variable developmental delay and other neurologic problems such as seizures and low muscle tone.
Fibro-adipose vascular anomaly, also known as FAVA, is a type of vascular anomaly that is both rare and painful. FAVA is characterized by tough fibrofatty tissue taking over portions of muscle, most often contained within a single limb. FAVA also causes venous and/or lymphatic abnormalities.
Facial infiltrating lipomatosis (FIL), also referred to as congenital infiltrating lipomatosis of the face or facial infused lipomatosis, is an ultra-rare craniofacial overgrowth condition caused by a genetic mutation of the PIK3CA gene. The condition is a part of the PIK3CA related overgrowth spectrum (PROS). The disease is congenital and non-hereditary. First described by Slavin and colleagues in 1983.
PIK3CA-related overgrowth spectrum (PROS) is an umbrella term for rare syndromes characterized by malformations and tissue overgrowth caused by somatic mutations in PIK3CA gene. In PROS diseases individuals malformations are seen in several different tissues such as skin, vasculature, bones, fat and brain tissue depending on the specific disease.
Diffuse capillary malformation with overgrowth (DCMO) is a subset of capillary malformations (CM) associated with hypertrophy, i.e. increased size of body structures. CM can be considered an umbrella term for various vascular anomalies caused by increased diameter or number of capillary blood vessels. It is commonly referred to as "port-wine stain", and is thought to affect approximately 0.5% of the population. Typically capillaries in the papillary dermis are involved, and this gives rise to pink or violaceous colored lesions. The majority of DCMO lesions are diffuse, reticulated pale-colored stains.