Hartnup Disease

Disease database

Hartnup Disease is a rare genetic disorder that affects the body’s ability to absorb certain amino acids. It is named after the Hartnup family, who were the first to be diagnosed with this condition in the 1950s. This article will explore the various symptoms and characteristics of Hartnup Disease, as well as potential treatment options.

Photosensitivity: A Common Symptom

One of the most noticeable symptoms of Hartnup Disease is photosensitivity, which refers to an increased sensitivity to sunlight. Individuals with this condition may experience a severe skin reaction when exposed to sunlight, resulting in a rash or sunburn-like appearance. This photosensitivity can be quite uncomfortable and may require individuals to take extra precautions when spending time outdoors.

Skin Rash: A Visible Indicator

In addition to photosensitivity, individuals with Hartnup Disease may also develop a skin rash. This rash typically appears on areas of the body that are exposed to sunlight, such as the face, neck, and arms. The rash may be red and itchy, and can vary in severity from person to person. It is important for individuals with Hartnup Disease to protect their skin from the sun and seek medical attention if the rash becomes severe or persistent.

Cerebellar Ataxia: Affecting Coordination

Cerebellar ataxia is another common symptom of Hartnup Disease. This condition affects the cerebellum, which is the part of the brain responsible for coordinating movement and balance. Individuals with cerebellar ataxia may experience difficulties with coordination, such as unsteady walking or clumsiness. This can significantly impact their daily lives and may require the use of assistive devices or physical therapy to manage.

Pellagra-like Symptoms: A Nutritional Deficiency

Hartnup Disease can also lead to pellagra-like symptoms, which are similar to those caused by a deficiency in niacin (vitamin B3). Niacin is essential for the body’s metabolism and energy production. When individuals with Hartnup Disease are unable to properly absorb amino acids, it can result in a deficiency of niacin and other important nutrients. This can lead to symptoms such as fatigue, digestive issues, and skin problems.

Aminoaciduria: Impaired Amino Acid Absorption

Aminoaciduria is a key characteristic of Hartnup Disease. It refers to the impaired absorption of certain amino acids in the kidneys. Amino acids are the building blocks of proteins and play a crucial role in various bodily functions. When individuals with Hartnup Disease are unable to absorb these amino acids properly, it can lead to a range of symptoms and complications.

Treatment Options

While there is currently no cure for Hartnup Disease, there are treatment options available to manage the symptoms and improve quality of life. These may include:

  • Supplementing with niacin: Since individuals with Hartnup Disease may have difficulty absorbing niacin, supplementation may be necessary to prevent pellagra-like symptoms.
  • Dietary modifications: A diet rich in protein and certain amino acids may help compensate for the impaired absorption in individuals with Hartnup Disease.
  • Sun protection: Due to the photosensitivity associated with Hartnup Disease, it is important for individuals to protect their skin from sunlight by wearing protective clothing, using sunscreen, and avoiding excessive sun exposure.
  • Supportive care: Depending on the severity of symptoms, individuals with Hartnup Disease may benefit from physical therapy, occupational therapy, or other supportive care measures to manage cerebellar ataxia and improve overall functioning.

It is important for individuals with Hartnup Disease to work closely with healthcare professionals to develop a personalized treatment plan that addresses their specific needs and symptoms.

In conclusion, Hartnup Disease is a rare genetic disorder that affects the body’s ability to absorb certain amino acids. It is characterized by symptoms such as photosensitivity, skin rash, cerebellar ataxia, pellagra-like symptoms, and aminoaciduria. While there is no cure for this condition, treatment options are available to manage symptoms and improve quality of life. By understanding the symptoms and seeking appropriate medical care, individuals with Hartnup Disease can lead fulfilling lives and minimize the impact of this rare disorder.

Haroon Rashid, MD
Rate author
Urgent Care Center of Arlington, VA