What are the other Names for this Condition? (Also known as/Synonyms)
- Albinism with Hemorrhagic Diathesis
- Delta Storage Pool Disease due to Hermansky-Pudlak Syndrome
- Platelet Defects and Oculocutaneous Albinism
What is Hermansky-Pudlak Syndrome? (Definition/Background Information)
- Hermansky-Pudlak Syndrome (HPS) is a subtype of oculocutaneous albinism, which is a main type of albinism. It is a rare inherited abnormality
- This congenital defect occurs when the child inherits defective genes from both the parents in an autosomal recessive manner. HPS is usually found in Puerto Ricans
- The disorder mainly affects the vision, blood, and skin, causing severe conditions. Symptomatic treatment is provided to address the major medical issues
- However, the prognosis for Hermansky-Pudlak Syndrome is mostly guarded
Who gets Hermansky-Pudlak Syndrome? (Age and Sex Distribution)
- Hermansky-Pudlak Syndrome is a congenital disorder affecting individuals of both male and female gender
- However, Puerto Ricans (residents of Puerto Rico, an US territory in the Caribbean) exhibit a higher prevalence of HPS. This disorder seems to be somewhat unique to them
What are the Risk Factors for Hermansky-Pudlak Syndrome? (Predisposing Factors)
Risk factors of Hermansky-Pudlak Syndrome include:
- HPS is an inherited disorder; individuals with family members (past or present) having the disorder, are at a high risk
- Puerto Ricans are more prone to this type of albinism, than any other race or ethnic group
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones 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 Hermansky-Pudlak Syndrome? (Etiology)
- Hermansky-Pudlak Syndrome is the result of defective metabolic reactions with complex genetic mutations. The genetic defect run in the families and is inherited in an autosomal recessive manner
- In HPS, a child inherits the defective genes from both parents. If, only one parent’s genes are defective, then the child becomes only a carrier of the disorder, exhibiting no signs and symptoms of the condition
- Nine types of this disorder have been identified. HPS is characterized by partial or decreased pigmentation, abnormalities of blood platelets, and increased accumulation of fat-proteins
Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).
What are the Signs and Symptoms of Hermansky-Pudlak Syndrome?
Three specific sets of signs and symptoms are present in Hermansky-Pudlak Syndrome -affected individuals. These are related to the skin and eyes (hence the term ‘oculocutaneous albinism’), blood, and abnormal protein storage within the cells.
Signs and symptoms related to the skin and eyes:
- Lack of coloration (pale white, yellow appearance, lighter than normal color) of the hair and skin. Sometimes, patchiness on the skin is noticed
- Photosensitivity of the skin
- Pale blue, red, or purple iris (in the eye)
- Decreased vision or lack of visual clarity, intolerance to light
- Nystagmus - an irregular, involuntary/voluntary, continuous back and forth eye movement
- Astigmatism (blurred vision, images are not sharp) and refractive errors
- Strabismus - squint of the eye, crossed eyes
- Macular hypoplasia - a rare eye defect due to retinal abnormalities
Signs and symptoms related to the blood:
- Platelet dysfunction is observed, leading to bleeding disorders
- Individuals with HPS may suffer from a loss of blood clotting
Signs and symptoms related to abnormal cellular storage:
- There may be an accumulation of ceroid (a golden-colored wax-like pigment) in the cells and tissues, causing cellular storage disorders
- These may affect vital organs like the kidneys, intestine, heart, and lungs, causing them severe damage
Apart from these, Hermansky-Pudlak Syndrome may also cause an inflammation of the colon (granulomatous colitis).
How is Hermansky-Pudlak Syndrome Diagnosed?
A diagnosis of Hermansky-Pudlak Syndrome may involve:
- Manifestations of HPS are generally diagnosed on a clinical examination, corroborated with other diagnostic tests. Signs and symptoms are key pointers to the physician, along with a family medical history
- Examination of the platelets using an electron microscope
- Eye vision testing and checkup, by an ophthalmologist
- VEP (Visual-Evoked Potential) testing in children with visual problems and other signs of albinism
- Genetic testing of the HPS genes (especially performed in Puerto Ricans)
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 Hermansky-Pudlak Syndrome?
Some of the complications of Hermansky-Pudlak Syndrome are:
- Malfunctioning of vital organs like the heart, kidney, lung, or intestine
- Individuals in the age group of 40-50 years may be presented with pulmonary fibrosis, which can be fatal
- Injuries and accidents that cause severe bleeding; or other issues that cause a hemorrhage, due to abnormal platelet function
- Reduced eye functionality, eye sensitivity, visual problems
- Skin cancer and sunburn
- Social and cultural ostracism, isolation
How is Hermansky-Pudlak Syndrome Treated?
Hermansky-Pudlak Syndrome is a genetically inherited disorder with no known cure. Vitamin E therapies with antidiuretics are prescribed for those who regularly have hemorrhages. Most of the treatment measures are typically related to correction of ocular defects and preservation of eye functionality.
For ocular disorders:
- Aids to help low or poor vision, like special (bioptic) glasses
- Tinted glasses to reduce light sensitivity, use of UV-protected sunglasses
- Use of wide-brimmed hats, for sunny days
- Surgical correction for strabismus, nystagmus
For skin protection:
- Use of sunscreens with a high SPF (sun protection factor)
- Protective clothing and wide-brimmed hats
How can Hermansky-Pudlak Syndrome be Prevented?
- Currently, there are no specific methods or guidelines to prevent Hermansky-Pudlak Syndrome genetic condition
- 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 Hermansky-Pudlak Syndrome? (Outcomes/Resolutions)
- The prognosis for Hermansky-Pudlak Syndrome depends upon the severity of signs and symptoms presented
- Individuals with HPS who exhibit mild symptoms and presentations may have a normal life, unless any complications develop
- However, most cases of HPS are fatal and the prognosis is generally poor. Bleeding and cellular storage disorders are often very serious conditions, which may result in fatalities
Additional and Relevant Useful Information for Hermansky-Pudlak Syndrome:
Most of the medical research and findings with respect to Hermansky-Pudlak Syndrome are based on studies conducted on the Puerto Ricans.