The reported incidence of constriction ring syndrome varies from 1/1200 and 1/15000 live births. The prevalence is equally in male and female.

Fetomaternal factors like prematurity, maternal illnes, low birth weight and maternal drug exposure are predisposing factors for the constriction ring syndrome.

No positive relationship between CRS and genetic inheritance has been reported.

The prognosis is favorable in most patients with an isolated cutaneous abnormality. In the majority of cases, both the vivid red marking and the difference in circumference of the extremities regress spontaneously during the first year of life. It is theorized that this may be due to the normal maturation process, with thickening of the epidermis and dermis. Improvements for some patients can continue for up to 10 years, while in other cases, the marbled skin may persist for the patient's lifetime.

One study reported an improvement in lesions in 46% of patients within 3 years. If CMTC persists into adulthood, it can result in complaints due to paresthesia, increased sensitivity to cold and pain, and the formation of ulcers.

Few reports included long-term follow up of CMTC into adolescence and adulthood. While about 50% of patients seem to show definite improvement in the reticular vascular pattern, the exact incidence and cause of persistent cases are unknown.

Fewer than 100 cases of CMTC have been published worldwide. Petrozzi reported the first case of CMTC in the United States in 1970. CMTC is believed to be more common than suspected, as studies have shown that milder forms of the disease are not being recognized as CMTC.

The pathophysiology is still unclear, with most cases occurring sporadically, although rare cases were reported in families. Studies indicated the primary involvement of capillaries, venules and veins, and possibly also that of arterioles and lymphatics.

Hypotheses that have been proposed include: environmental/external factors; peripheral neural dysfunction; failure of the development of mesodermic vessels in an early embryonic stage; autosomal dominant inheritance with incomplete penetrance and, finally, the theory of Happle.

There has been a great deal of research to understand the cause of PHACE Syndrome. The abnormalities associated with this syndrome are thought to be due to errors that occur very early during development. Unfortunately, why the errors occur, or the exact cause is still unknown. PHACE has a shared biology of other vascular anomalies. There may be a genetic component involved and studies are underway to investigate this idea. No familial cases have been identified to date. Research is ongoing to find the cause of all vascular anomalies including PHACE Syndrome.

The nature of this malformation remains unclear. Congenital, spontaneous, and acquired origins are accepted. The hypothesis of a spontaneous origin in the current case of SP is supported by no evidence of associated anomalies, such as cerebral aneurysmal venous malformations, systemic angiomas, venous angioma dural malformation, internal cerebral vein aneurysm, and cavernous hemangiomas.

The overall prognosis is excellent in most cases. Most children with Adams–Oliver syndrome can likely expect to have a normal life span. However, individuals with more severe scalp and cranial defects may experience complications such as hemorrhage and meningitis, leading to long-term disability.

Sinus pericranii (SP) is a rare disorder characterized by a congenital (or occasionally, acquired) epicranial venous malformation of the scalp. Sinus pericranii is an abnormal communication between the intracranial and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for aesthetic reasons and prevention of hemorrhage.

Hepatic microvascular dysplasia (HMD or MVD) or portal atresia is a disorder where mixing of venous blood and arterial blood in the liver occurs at the microscopic level. It occurs most commonly in certain dog breeds such as the Cairn and Yorkshire terriers although any dog breed may be at risk.

This disease may also be found in cats.

HMD is sometimes misdiagnosed as Portosystemic vascular anomaly (PSVA) or a "Liver Shunt" (portosystemic shunt). HMD can be diagnosed with an MRI, using a tracing dye in the subject's blood, and observing the flow of blood through the subject's liver and surrounding areas (stomach, intestine) for anomalies. It can also be diagnosed using a bile-acid level test; or more accurately, a "fasting-blood ammonia levels" test. Symptoms include stunted growth in the first 6–9 months, vomiting, seizures, and hydro-encephalitic episodes (from ammonia concentrating in the blood). HMD is usually treated non-surgically with antibiotics (metronidazole) and stool-softeners (lactulose).

Amniotic banding affects approximately 1 in 1,200 live births. It is also believed to be the cause of 178 in 10,000 miscarriages. Up to 50% of cases have other congenital anomalies including cleft lip, cleft palate, and clubfoot deformity. Hand and finger anomalies occur in up to 80%.

PHACE Syndrome is the uncommon association between large infantile hemangiomas, usually of the face, and birth defects of the brain, heart, eyes, skin and/or arteries. It is an acronym that stands for the medical names of the parts of the body it often impacts:

- Posterior fossa abnormalities and other structural brain abnormalities

- Hemangioma(s) of the cervical facial region

- Arterial cerebrovascular anomalies

- Cardiac defects, aortic coarctation and other aortic abnormalities

- Eye anomalies

Sometimes an "S" is added to PHACE making the acronym PHACES; with the "S" standing for "Sternal defects" and/or "Supraumbilical raphe."

In 1993, an association between large facial hemangiomas and brain defects among 9 subjects was reported. 3 years later, a larger case study was published showing a wider spectrum of grouped malformations. The association of anomalies and the PHACES acronym was first coined by Dr. Vail Reese and Dr. Ilona Frieden in 1996, making it a newly described syndrome. A diagnosis is generally made from the physical examination, along with imaging of the head and chest, and an eye examination. PHACE is most commonly diagnosed among female infants. Long-term quality of life varies.

Hemangioma growth phase can last anywhere from 6 to 18 months. Then involution, or healing, of the hemangioma begins. Laser and other surgeries usually are able to make a substantial positive impact on appearance. Long after the hemangioma recedes, any damage it or the other defects caused, may remain. Migraines are common, as are developmental delays.

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm that is locally aggressive but without metastatic potential. It occurs particularly in the skin, deep soft tissue, retroperitoneum, mediastinum, and rarely in bone. Although lesions occur solitary, they often involve large areas of the body, such as the head/neck region (40%), trunk (30%), or extremity (30%).

Usually, it is present at birth as a flat, reddish-purple, tense and edematous lesion.

Although half of lesions are congenital, 58% of KHE develop during infancy, 32% between age 1 and 10 years (32%) and 10% after 11 years of age. Moreover, adult onset has been described too with mainly males being affected. Both sexes are affected equally in children.

Lesions are often greater than 5 cm in diameter and can cause visible deformity and pain. During early childhood, KHE may enlarge and after 2 years of age, it may partially regress. Though, it usually persists longterm. In addition, 50% of patients suffer from coagulopathy due to thrombocytopenia (<25,000/mm3), presenting with petechiae and bleeding. This is called the Kasabach-Merritt Phenomenon, which is caused by trapping of platelets and other clotting factors within the tumor. Kasabach-Merritt Phenomenon is less likely in patients with lesions less than 8 cm. As two-thirds of adult-onset KHE tumors are less than 2 cm, KHE in adults is rarely associated with Kasabach-Merritt Phenomenon.

Patients with KHE and Kasabach-Merritt Phenomenon present with petechiae and ecchymosis.

Most KHE tumors are diffuse involving multiple tissue planes and important structures. Resection of KHE is thus often difficult. Treatment of kaposiform hemangioendothelioma is therefore medical. The primary drug is interferon alfa, which is successful in 50% of children. Another option is vincristine, which has lots of side-effects, but has a response rate of 90%. Drug therapy is often used in shrinking the tumor and treating the coagulopathy. However, many of these kaposiform hemangioendotheliomas do not completely regress and remain as a much smaller asymptomatic tumor. However, KHE still has a high mortality rate of 30%. Although complete surgical removal with a large margin has the best reported outcome, it is usually not done because of the risk of bleeding, extensiveness, and the anatomic site of the lesion.

Operative management may be possible for small or localized lesions. Removal of larger areas also may be indicated for symptomatic patients or for patients who have failed farmacotherapy. Resection is not required for lesions that are not causing functional problems, because KHE is benign and because resection could cause deformity.

Surgical correction is recommended when a constriction ring results in a limb contour deformity, with or without lymphedema.

A vascular anomaly is a kind of birthmark caused by a disorder of the vascular development, although it is not always present at birth. A vascular anomaly is a localized defect in blood vessels that can affect each part of the vasculature (capillaries, arteries, veins, lymphatics or a combination of these). These defects are characterized by an increased number of vessels and vessels that are both enlarged and sinuous. Some vascular anomalies are congenital and therefore present at birth, 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 patients’ age. Vascular anomalies can also be a part of a syndrome and, occasionally, they can be acquired by trauma. The estimated prevalence of vascular anomalies is 4.5%. Vascular anomalies can occur throughout the whole body (skin, bone, liver, intestines, i.e.), but in 60% of patients vascular anomalies are localized in the head and neck region.

Vascular anomalies can present in various ways. Vascular anomalies that are situated deep below the skin, appear blue and are often called cavernous. Superficial vascular anomalies appear as red-coloured stains and are associated with vascular anomalies affecting the dermis. Historically, vascular anomalies have been labeled with descriptive terms, according to the food they resembled (port wine, strawberry, cherry, salmon patch). This imprecise terminology has caused diagnostic confusion, blocked communication and even caused incorrect treatment, as it does not differentiate between various vascular anomalies. However, in 1982, Mulliken introduced a classification that replaced these descriptive terms and gave direction to the management of various vascular anomalies. This classification, based on clinical features, natural history and cellular characteristics, divides vascular anomalies into two groups: vascular tumors and vascular malformations.

Although the appearance of both vascular tumors and vascular malformations can resemble, there are important differences between both.

The incidence in the general population is roughly 0.5%, and clinical symptoms typically appear between 20 to 30 years of age. Once thought to be strictly congenital, these vascular lesions have been found to occur "de novo". It may appear either sporadically or exhibit autosomal dominant inheritance.

The prognosis depends on the location and severity of the constricting bands. Every case is different and multiple bands may be entangled around the fetus.

Bands which wrap around fingers and toes can result in syndactyly or amputations of the digits. In other instances, bands can wrap around limbs causing restriction of movement resulting in clubbed feet. In more severe cases, the bands can constrict the limb causing decreased blood supply and amputation. Amniotic bands can also sometimes attach to the face or neck causing deformities such as cleft lip and palate. If the bands become wrapped around the head or umbilical cord it can be life-threatening for the fetus.

The number of cases of miscarriage that can be attributed to ABS is unknown, although it has been reported that it may be the cause of 178 in 10,000 miscarriages.

A malformative syndrome (or malformation syndrome) is a recognizable pattern of congenital anomalies that are known or thought to be causally related (VIIth International Congress on Human Genetics).

Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome

AOS is a rare genetic disorder and the annual incidence or overall prevalence of AOS is unknown. Approximately 100 individuals with this disorder have been reported in the medical literature.

Treatment is symptomatic, often addressing indicators associated with peripheral pulmonary artery stenosis. Laryngotracheal calcification resulting in dyspnea and forceful breathing can be treated with bronchodilators including the short and long-acting β2-agonists, and various anticholinergics. Prognosis is good, yet life expectancy depends on the severity and extent of diffuse pulmonary and arterial calcification.

Central nervous system cavernous hemangioma is a cavernous hemangioma that arises in the central nervous system (CNS). It can be considered to be a variant of hemangioma, and is characterized by grossly large dilated blood vessels and large vascular channels, less well circumscribed, and more involved with deep structures, with a single layer of endothelium and an absence of neuronal tissue within the lesions. These thinly walled vessels resemble sinusoidal cavities filled with stagnant blood. Blood vessels in patients with cerebral cavernous malformations (CCM) can range from a few millimeters to several centimeters in diameter. Most lesions occur in the brain, but any organ may be involved.

Prognosis varies widely depending on severity of symptoms, degree of intellectual impairment, and associated complications. Because the syndrome is rare and so newly identified, there are no long term studies.

The incidence of VACTERL association is estimated to be approximately 1 in 10,000 to 1 in 40,000 live-born infants. It is seen more frequently in infants born to diabetic mothers. While most cases are sporadic, there are clearly families who present with multiple involved members.

This condition has been linked to mutations in the ribosomal GTPase BMS1 gene.

Craniosynostosis–anal anomalies–porokeratosis syndrome (also known as "CAP syndrome") is a cutaneous condition inherited in an autosomal recessive fashion.

There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery

Genetic counseling and screening of the mother's relatives is recommended.