Cystinosis

Disease database

Cystinosis is a rare genetic disorder that affects the body’s ability to transport the amino acid cystine out of the cells. This leads to an accumulation of cystine within the cells, causing various health problems. In this article, we will explore the different aspects of cystinosis and its impact on the body.

Polyuria and Polydipsia

One of the early signs of cystinosis is excessive urination, known as polyuria, and increased thirst, known as polydipsia. This occurs due to the impaired ability of the kidneys to reabsorb water and electrolytes, leading to increased urine production. Individuals with cystinosis may experience frequent trips to the bathroom and an unquenchable thirst.

Growth Retardation

Cystinosis can also cause growth retardation in children. The accumulation of cystine within the cells affects the normal functioning of various organs, including the bones and muscles. This can result in stunted growth and delayed development. Early diagnosis and treatment are crucial to managing this aspect of the disease.

Renal Tubular Acidosis

Renal tubular acidosis is a condition where the kidneys are unable to maintain the proper acid-base balance in the body. In cystinosis, the accumulation of cystine within the renal tubules disrupts their normal function, leading to acidosis. This can cause symptoms such as fatigue, weakness, and electrolyte imbalances.

Photophobia

Photophobia, or sensitivity to light, is another common symptom of cystinosis. The accumulation of cystine crystals in the cornea can lead to eye discomfort and increased sensitivity to bright lights. Individuals with cystinosis may need to wear sunglasses or avoid bright environments to alleviate this symptom.

Hypophosphatemic Rickets

Cystinosis can also affect the bones, leading to a condition called hypophosphatemic rickets. This occurs due to the impaired reabsorption of phosphate by the kidneys, resulting in low levels of phosphate in the blood. Phosphate is essential for bone health, and its deficiency can cause weak and brittle bones.

Muscle Wasting

As cystinosis progresses, it can lead to muscle wasting and weakness. The accumulation of cystine within the muscle cells interferes with their normal function, causing muscle deterioration. This can result in decreased muscle strength and mobility, making everyday tasks challenging for individuals with cystinosis.

Hypothyroidism

Hypothyroidism, or an underactive thyroid gland, is another complication associated with cystinosis. The thyroid gland plays a crucial role in regulating metabolism and energy levels. In cystinosis, the accumulation of cystine within the thyroid gland can disrupt its function, leading to decreased thyroid hormone production and a range of symptoms such as fatigue, weight gain, and cold intolerance.

Hypogonadism

Cystinosis can also affect the reproductive system, leading to hypogonadism. This condition is characterized by reduced production of sex hormones, resulting in delayed puberty, infertility, and sexual dysfunction. Hormone replacement therapy may be necessary to manage this aspect of cystinosis.

Treatment and Management

While there is currently no cure for cystinosis, early diagnosis and treatment can significantly improve the quality of life for individuals with the condition. The primary goal of treatment is to reduce the accumulation of cystine within the cells and manage the associated symptoms.

Cystine Depletion Therapy

Cystine depletion therapy involves the use of medications such as cysteamine to lower the levels of cystine in the cells. This helps prevent the progression of the disease and alleviate some of the symptoms. Regular monitoring of cystine levels and adherence to the prescribed treatment regimen are essential for its effectiveness.

Kidney Transplantation

In severe cases of cystinosis where kidney function is severely compromised, a kidney transplant may be necessary. This can help improve renal function and overall health. However, it is important to note that cystinosis affects other organs as well, so a kidney transplant does not cure the underlying genetic disorder.

Supportive Care

Supportive care plays a crucial role in managing cystinosis. This includes regular monitoring of kidney function, nutritional support to address growth retardation, and management of associated complications such as hypothyroidism and hypogonadism. Physical therapy and assistive devices may also be beneficial in maintaining mobility and independence.

Conclusion

Cystinosis is a complex genetic disorder that affects multiple organs and systems in the body. Early diagnosis, proper management, and ongoing support are essential for individuals with cystinosis to lead fulfilling lives. While there is no cure for the condition, advancements in treatment options have significantly improved outcomes for those affected. By raising awareness and supporting research efforts, we can continue to enhance the understanding and management of cystinosis.

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