What are the other Names for this Condition? (Also known as/Synonyms)

• HNA (Hereditary Neurocutaneous Angioma)

What is Hereditary Neurocutaneous Angioma? (Definition/Background Information)

• Hereditary Neurocutaneous Angioma (HNA) is an extremely uncommon and recently described genetic disorder that is manifested by the presence of skin and brain lesions (called angiomas). It is inherited in an autosomal dominant manner
• The disorder may result in severe symptoms and complications when the central nervous system is involved. A treatment of Hereditary Neurocutaneous Angioma involves surgical excision to remove the cerebral and cutaneous lesions. The prognosis of the condition may vary from one individual to another

Who gets Hereditary Neurocutaneous Angioma? (Age and Sex Distribution)

• Hereditary Neurocutaneous Angioma is a rare congenital disorder that is reported in fewer than 10 families worldwide
• The presentation of symptoms typically occurs in childhood
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Hereditary Neurocutaneous Angioma? (Predisposing Factors)

• A positive family history may be an important risk factor, since Hereditary Neurocutaneous Angioma is an inherited condition
• Currently, no other specific risk factors have been identified

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hereditary Neurocutaneous Angioma? (Etiology)

• Hereditary Neurocutaneous Angioma is caused by genetic abnormalities which are passed down (through families) in an autosomal dominant pattern

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition, or pass it on to their offspring

What are the Signs and Symptoms of Hereditary Neurocutaneous Angioma?

The signs and symptoms of Hereditary Neurocutaneous Angioma may vary from one individual to another and may be mild or severe. The following are some reported signs and symptoms:

• Presence of hemangiomas on the trunk and upper limbs, including on the brain and spine
• Seizures
• Partial paralysis
• Horner syndrome - causing disruption of the nerve pathways
• Bleeding in the gastrointestinal tract
• Anemia, if there is prolonged bleeding in the gastrointestinal tract
• Blood in urine

How is Hereditary Neurocutaneous Angioma Diagnosed?

Hereditary Neurocutaneous Angioma is diagnosed on the basis of the following information:

• Complete physical examination with evaluation of family medical history
• Neurological examination
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Imaging studies of the head and neck region
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Prenatal testing in pregnant women

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hereditary Neurocutaneous Angioma?

The complications of Hereditary Neurocutaneous Angioma may include:

• Reduced mobility, owing to weakness on one side of the body
• Bleeding in the brain
• Trauma/injury: Seizures can lead to fall injuries affecting the head, or cause bone fractures
• Status epilepticus, a seizure that lasts longer than normal, and considered a serious life-threatening condition and is a medical emergency. A time duration of 30-60 minutes is generally considered a minimum requirement for usage of the term Status Epilepticus, to describe the condition
• Psychological issues, especially depression, anxiety, and in some cases suicidal tendencies are noted
• Complications during pregnancy:
  • There is a potential for reduction in fertility
  • Certain anti-epileptic medications increase the risk of birth defects
• Sudden unexplained deaths with epilepsy, possibly due to disturbances in the heart's rhythm or from breathing issues

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Hereditary Neurocutaneous Angioma Treated?

There is no cure for Hereditary Neurocutaneous Angioma since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops. These may include:

• Surgical resection and tumor removal: Wide surgical excision with removal of the entire lesion is the preferred treatment method. If the tumor is not fully removed, then it might recur

• Embolization is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
• Microsurgery through an open-skull incision to remove the tumor
• When the tumor is inaccessible to surgery, it may be treated with focused radiation using stereotactic radiosurgery

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

How can Hereditary Neurocutaneous Angioma be Prevented?

Hereditary Neurocutaneous Angioma may not be preventable since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

What is the Prognosis of Hereditary Neurocutaneous Angioma? (Outcomes/Resolutions)

The prognosis of Hereditary Neurocutaneous Angioma is dependent upon the severity of the signs and symptoms and associated complications, if any.

• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• In many individuals, lesions involving the central nervous system, especially the brain, may resulting in debilitating complications and even fatalities

Additional and Relevant Useful Information for Hereditary Neurocutaneous Angioma:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/