Cystinosis can target multiple organs in the body and, thus, has a wide symptom presentation. Aside from kidney dysfunction, the disease can also present with thyroid dysfunction in the form of hypothyroidism, diabetes mellitus, swallowing difficulties and muscle wasting.

Infantile nephropathic cystinosis usually presents in children who otherwise are normal at birth. By the age of 10 months, patients start displaying symptoms particular to the disease such as growth stunting, frequent urination, irritability and increased thirst. Unlike healthy children, affected children are unable to walk or bear significant weight by 12 months of age. Infantile nephropathic cystinosis is considered the most severe form of the disease.

A characteristic signature of cystinosis is an associated Fanconi syndrome, defined by an inability to absorb many minerals and elements in the proximal renal tubules. The nutrients are subsequently excreted in the urine and, if not replaced, patients can suffer from severe electrolyte and acid-base abnormalities. Children generally have a poor appetite for certain foods, demand salt and display stunted growth. Without treatment, children suffering from this form of the disease can undergo kidney failure before the age of 10.

Other forms of cystinosis may first present in adolescence or even adulthood. Juvenile or adolescent cystinosis is characterized by renal and ocular symptoms. Adult cystinosis, on the other hand, is a benign condition in which the cornea of the eye is almost exclusively the site of cystine deposition.

• Infertility

  Cystine deposits in various organs progressively lead to additional manifestations such as hypothyroidism, hypogonadism and male infertility, insulin-dependent diabetes, hepatosplenomegaly with portal hypertension, muscle involvement with distal muscle [orpha.net]

  Other complications of untreated cystinosis, especially after adolescence, may include muscle deterioration, blindness, difficulty swallowing, diabetes, thyroid and nervous system problems, and infertility (an inability to father children) in affected [leadiant.com]

  Other signs and symptoms that may occur in untreated people, especially after adolescence, include muscle deterioration, blindness, inability to swallow, diabetes, thyroid and nervous system problems, and an inability to father children (infertility) [ghr.nlm.nih.gov]

• Pediatric Disease

  Pediatr Nephrol 2014;29:1097-102. [PUBMED] 8. Theodoropoulos DS, Krasnewich D, Kaiser-Kupfer MI, Gahl WA. Classic nephropathic cystinosis as an adult disease. JAMA 1993; 270:2200-4. [PUBMED] 9. Broyer M. Cystinosis. [sjkdt.org]

  Pollak, 2008 5 Cognitive and Behavioral Abnormalities of Pediatric Diseases TREATMENT Recently, an effective treatment was approved for the treatment of cystinosis. [educalingo.com]

  In: Cognitive and Behavioral Abnormalities of Pediatric Diseases, Nass RD, Frank Y, eds. 2010 Oxford University Press, New York, NY. pp. 333-341. Gahl WA. Cystinosis. [rarediseases.org]

• Weight Loss

  Since the age of five months, he developed symptoms of severe weight loss, vomiting, dehydration, and polyuria. He manifested the Toni Debré Fanconi syndrome. [sjkdt.org]

  Excessive thirst and peeing (urination) Reduced appetite Weight loss Slow growth Softening or weakening of bones (rickets) Eventually, the damage caused by cystinosis causes the kidneys to fail completely, which can be treated only with dialysis (an artificial [procysbi.com]

• Failure to Thrive

  Initial presentation of infantile nephropathic cystinosis The initial symptoms include polydipsia, polyuria, vomiting, loss of appetite, constipation, and failure to thrive. [emedicine.medscape.com]

  The history of muscle weakness, failure to thrive, polydipsia, and polyuria prompted subsequent clinical and laboratory evaluations, leading to the correct diagnosis of cystinosis. [ncbi.nlm.nih.gov]

  The disease results in deposition of crystals throughout the body; if untreated, it leads to failure to thrive, profound metabolic imbalance, early end-stage renal disease, thyroid failure, and multiorgan dysfunction. [doi.org]

• Dysphagia

  Slow eating and dysphagia are common. Heterozygotes may have elevated levels of free cystine in leukocytes. The later onset juvenile form of cystinosis presents with kidney failure secondary to glomerular damage instead of tubular dysfunction. [disorders.eyes.arizona.edu]

  […] cystinosis  Corneal crystals  Renal involvement which if not treated lead to renal failure by age of nine, also may lead to proximal tubular dysfunction (Fanconi syndrome)  Hypothyroidism, hypogonadism and Impaired glucose tolerance  Myopathy  Dysphagia [slideshare.net]

  A subset of patients may also suffer from dysphagia, malnutrition and frequent aspiration. These patients are usually treated with an implantation of a gastrostomy tube. [symptoma.com]

  These include myopathy and dysphagia due to the accumulation of cystine in the muscles, endocrine involvement such as hypothyroidism and diabetes mellitus, hepatomegaly, hypersplenism and photophobia from the accumulation of cystine in the cornea. [sjkdt.org]

• Loss of Appetite

  Children with this type of cystinosis often have short stature, changes in the retina (retinopathy), sensitivity to light (photophobia), vomiting, loss of appetite, and constipation. [verywellhealth.com]

  The most common side effects are anorexia (loss of appetite), vomiting, nausea (feeling sick), lethargy (low energy) and pyrexia (fever). [alternativemedicals.com]

  […] of appetite Craves salty and hot and spicy foods; prefers specific food textures May have recurrent bouts of fever and manifestations of heat intolerance Left untreated, renal failure develops by age 7-10 years Signs and symptoms of late-onset (intermediate [emedicine.medscape.com]

• Halitosis

  KEYWORDS: Carbohydrate-cysteamine thiazolidines; Cysteamine; Cystinosis; Halitosis; Pro-drug [ncbi.nlm.nih.gov]

  The gastrointestinal side effect, halitosis and body odor, are reduced, though not eliminated, according to the parents of children with the disease. Christopher M. [nytimes.com]

• Hypertension

  In addition, endoscopy in the first patient showed varices and portal hypertensive gastropathy. NRH was confirmed by histologic examination of the liver in both patients and is the likely cause of their portal hypertension. [ncbi.nlm.nih.gov]

• Hypotension

  (in 50% of cases, usually children), provoked by aspirin therapy; aspirin is proscribed for children less than 16 years old Riley–Day syndrome; familial dysautonomia autosomal-dominant complete indifference to pain; also characterized by orthostatic hypotension [medical-dictionary.thefreedictionary.com]

• Hepatosplenomegaly

  Cystine deposits in various organs progressively lead to additional manifestations such as hypothyroidism, hypogonadism and male infertility, insulin-dependent diabetes, hepatosplenomegaly with portal hypertension, muscle involvement with distal muscle [orpha.net]

• Muscular Atrophy

  척수성 근육위축(Spinal muscular atrophy) 7. 디 죠지 증후군(Di George's syndrome) 8. 표피 수포증(Epidermolysis bullosa) 9. 고세병(Gaucher's disease) 10. 레쉬 니한 증후군(Lesch Nyhan syndrome) 11. 마르팡 중후군(Marfan's syndrome) 12. 근육긴장성 장애(Myotonic dystrophy) 13. [hosp.ajoumc.or.kr]

• Photophobia

  The untreated cornea is packed with crystals by age 3-4 years, leading to photophobia in early childhood. [emedicine.medscape.com]

  Treatment Treatment Options: Topical cysteamine eye drops can dramatically reduce the number of cornea crystals and improve symptoms such as photophobia and visual acuity. [disorders.eyes.arizona.edu]

  Photophobia was relieved and IVCM obtained the decrease in size and density of corneal crystals 1 year after. Depth of corneal crystals did not change but crystal density score reduced with cysteamine treatment. [ncbi.nlm.nih.gov]

  Photophobia (excess sensitivity of the eye to light) occurs between mid-childhood and adolescence due to accumulation of cystine crystals in the cornea. Cystine storage in the thyroid leads to hypothyroidism usually around age 10. [medicinenet.com]

• Corneal Deposit

  Cystine crystal deposition can be seen in the bone marrow earlier than corneal deposition, in patients with NC. METHODS: Ten patients with cystinosis diagnosis were enrolled in the study. [ncbi.nlm.nih.gov]

  Topical cysteamine eye drops are also needed as systemic cysteamine has no effect on cystine corneal deposits. Prognosis Life expectancy is significantly improved with therapy. [orpha.net]

  Corneal deposits cause visual acuity deterioration. Therapy of metabolic keratopathy is based on systemic metabolic disorders treatment. In more advanced cases corneal transplantation is required. [okulistyka.com.pl]

• Retinal Damage

  The stored cystine is poorly soluble and crystallizes within the lysosomes of many cell types, leading to widespread tissue and organ damage. The image below depicts an infant at the time his cystinosis is diagnosed. [emedicine.medscape.com]

• Kidney Failure

  The kidney disease leads to a Fanconi syndrome type pattern of kidney failure. Pancreatic insufficiency, ovarian failure, myopathy, and central nervous system signs are often seen. [disorders.eyes.arizona.edu]

  Children with nephropathic cystinosis who are not treated for their condition typically experience complete kidney failure by about age 10. [britannica.com]

  The outlook with this disease changed for the better with cystine depletion therapy using cysteamine (Cystagon) which depletes cystinuric cells of most of their cystine, prevents kidney failure, and enhances growth. [medicinenet.com]

  Having too much cystine can damage your organs including your kidneys, eyes, pancreas, liver, and brain. Cystinosis can lead to permanent kidney damage and kidney failure. [kidneyfund.org]

• Polyuria

  At follow-up, the polyuria and hyponatremia were found to persist. [ncbi.nlm.nih.gov]

  These losses results in polyuria (excessive urination), polydipsia (excessive intake of fluid), dehydration (from the excess urination) hypophosphatemic rickets (due to loss of phosphate in the urine), and growth retardation (due to the renal disease) [medicinenet.com]

  His family history was significant with two sisters having died at the age of five and 13 months with clinical signs of dehydration and polyuria. [sjkdt.org]

• Confusion

  Don’t confuse “cystinosis” with “cystinuria”: they are different diseases, both genetic and both involving the amino acid cystine–but with decidedly different pathogeneses. [renalfellow.org]

  This disease must not be confused with cystinuria which is an autosomal recessive disorder characterised by a specific dibasic aminoaciduria, the result of a defective tubular reabsorption mechanism. [gpnotebook.co.uk]

  Budget Justification - Please explain items that might be confusing or unusual to the review committee. Key Personnel - Please include a current CV and indicate the percent effort that each person is expected to devote to the project. [ipna-online.org]

  They can have nephrotic syndrome, which can be confused with other causes.14 Generally, these patients have a slower progression to kidney failure. The adult, non-nephropathic ocular form of cystinosis typically only affects the eyes. [kidney.org]

  After the age of twenty, untreated cystinotic adults may develop cortical dysfunction with progressive confusion, tremor, and seizures [32]. [hindawi.com]

• Cerebral Calcification

  Cerebral calcifications and muscular and swallowing difficulties cluster around the third decade of life. [emedicine.medscape.com]

  calcifications or atrophy, swallowing dysfunction, diabetes mellitus, and liver disease (eg, hepatomegaly, nodular degenerative hyperplasia). [emedicine.com]

• Unable to Walk

  Unlike healthy children, affected children are unable to walk or bear significant weight by 12 months of age. Infantile nephropathic cystinosis is considered the most severe form of the disease. [symptoma.com]

The diagnosis of cystinosis is established after broad investigations that include the collection of pertinent history, performance of a physical exam and a range of testing modalities that help in elucidating the characteristic presenting symptoms as well as in conclusively diagnosing the disease. It is critical to diagnose the disease as early as possible, because prompt treatment can significantly improve prognosis and outcomes.

The presence of renal Fanconi Syndrome can be evaluated with urine analysis that identifies increased excretion of important minerals and compounds such electrolytes, water, carnitine and various amino acids [9]. Cystine crystals in the cornea of the eyes can be visualized with a slit lamp exam under high magnification. The slit lamp test may be sufficient for diagnosis when the test is done by an ophthalmologist.

Cystinosis can be also confirmed by assessing the levels of cystine in polymorphonuclear leukocytes, a particular type of white blood cells. Genetic testing may also help in identifying the responsible CTNS mutations for the disease. Such testing is usually provided by commercial laboratories.

Parents with known family history of the condition have the option of prenatal diagnosis. This can be performed through either sampling the fetal cells from the amniotic fluid or the chorionic villi. The latter are found on the placenta and may display high levels of cystine crystals that are characteristic of the disease.

• Nephrolithiasis

  Associated with nephrolithiasis (renal stones) [2] and renal failure. Autosomal recessive. [1] Mutation in cystinosin gene (CTNS). [3] [4] [5] Microscopic Kidney Multinucleation of podocytes. [6] [7] Images Case Cystinosis - intermed. mag. [librepathology.org]

  Imaging features are non-specific and may include: rickets renal medullary nephrocalcinosis nephrolithiasis Treatment and prognosis The mainstay of treatment is cystine-depleting therapy with cysteamine 7. [radiopaedia.org]

  Two patients were documented to have associated hypothy-roidism, while one patient each had nephrolithiasis and severe anemia. Three infants died due to metabolic disturbances and a six year old died due to end stage renal failure. [indianpediatrics.net]

• Glycosuria

  The de Toni-Fanconi syndrome* is a clinical constellation characterized by resistant rickets, acidosis, glycosuria, hyperamino-aciduria, and organic aciduria. [doi.org]

  All had nephropathic infantile-type cystinosis with evidence of proximal tubulopathy, with glycosuria and renal phosphate wasting. Diagnosis was confirmed in 19 cases by demonstrating an elevated cystine concentration in leukocytes. [ncbi.nlm.nih.gov]

  It is associated with slight increase of the plasma cystine, cystinuria, aminoaciduria, glycosuria, polyuria, hypophosphatemia, rickets, and renal tubular dysfunction Constellation of clinical and laboratory manifestations produced by generalized proximal [icd9data.com]

  Diagnostic methods The diagnosis is based on blood and urine analysis showing features of Fanconi syndrome (metabolic acidosis, hypokalemia, hyponatremia, hypophosphatemia, hyperaminoaciduria, glycosuria), detection of cystine crystals in the cornea by [orpha.net]

• Potassium Decreased

  The diagnosis of renal proximal tubulopathy (or renal Fanconi syndrome), often incomplete, was based on the usual criteria: Hyperaminoaciduria, glycosuria, tubular proteinuria with the presence of β2-microglobulin, renal loss of potassium, decreased reabsorption [cjasn.asnjournals.org]

• Hypouricemia

  […] criteria: Hyperaminoaciduria, glycosuria, tubular proteinuria with the presence of β2-microglobulin, renal loss of potassium, decreased reabsorption of phosphate and hypophosphoremia, reduction in bicarbonate reabsorption producing plasma acidosis, and/or hypouricemia [cjasn.asnjournals.org]

Treatment is targeted at the wide range of symptoms and clinical manifestations associated with the disease. A team of physicians and healthcare professionals that includes pediatricians, ophthalmologists, nephrologists, gastroenterologists and psychologists who may be necessary for the adequate treatment and management of the patient.

Cysteamine bitartrate is one of the most important medications that were developed for the treatment of cystinosis. It was first approved in 1994 by the Food and Drug Administrations and, later in 2013, an extended form of the drug was also permitted on the market. It acts by depleting the level of cystine in the cells, thereby decreasing the rate of crystal formation. The end result is a significant reduction in growth stunting and kidney dysfunction. Prompt and intense therapy with cysteamine can delay the need for a renal transplant by more than 20 years compared to patients who did not receive any treatment. Furthermore, life-long treatment may also prevent complications that involve other organs in different stages of the disease. An eye drop solution of cysteamine was specifically designed to target crystal formation in the cornea because the oral ingested form of the drug is ineffective for ocular manifestations. The eye drop solution is the only FDA approved method of treatment for ocular cystinosis [10].

On the other hand, fluid intake and electrolyte replacements are recommended in the cases of Fanconi syndrome. Supplementation therapy with magnesium, potassium, sodium citrate and bicarbonate may also be necessary. Acetylcholinesterase inhibitors can additionally be effective in delaying the onset and progression of kidney failure. Another medication that can be employed for the management of Fanconi syndrome is indomethacin. It is an anti-inflammatory drug that decreases the excretion of water and various electrolytes and may assist in limiting growth failure. It is worth mentioning, however, that individuals taking indomethacin require frequent monitoring of their kidney function. Other treatment options targeted at the symptomatic manifestations of the disease include vitamin D and phosphates for the prevention of rickets, carnitine to increase muscle strength, L-thyroxine for hypothyroidism, growth hormone therapy for growth abnormalities, insulin for diabetes mellitus and testosterone for boys suffering from hypogonadism. The ocular manifestations of the diseases can be prevented by wearing sunglasses and avoiding intense sunlight. Extreme cases that are associated with frequent corneal erosions, pain and large band keratopathies may require corneal transplantation. A subset of patients may also suffer from dysphagia, malnutrition and frequent aspiration. These patients are usually treated with an implantation of a gastrostomy tube. This procedure is performed through the insertion of a thin tube in the stomach, where nutritious materials and medications are directly deposited.

Kidney transplant is usually recommended at some stage of the disease, even when patients are treated early and adequately. It can sometimes be preceded with dialysis, when kidney function sufficiently deteriorates. Renal transplants can completely resolve Fanconi syndrome and usually result in a good success rate in patients with cystinosis. Nonetheless, it does not affect the deposition of cystine crystals in other organs and systems.

Prognosis of cystinosis has improved dramatically in the last four decades due to significant advances in treatment options. Before the advance of cysteamine and renal transplantation, patients usually suffered from progressive renal failure and passed away before the age of 10. Nowadays, patients suffering from the disease can expect to live to their 50s. This is especially because of the ability of cysteamine to slow renal failure. Studies on renal transplantation also showed that, in a large European sample, 5 year survival increased from 86.1% to 100% in children diagnosed with infantile nephropathic cystinosis who had received a kidney transplant [8].

Cystinosis is caused by genetic mutations that target the CTNS gene. The gene normally codes for cystinosin, a transporter protein. Mutations within this gene are responsible for all types of cystinosis. Cystinosin acts to transport cystine to the outside of the lysosomes, the cellular compartments that function to rid the cells of harmful substances. When the protein is defected, cystine can build within the lysosomes and form crystals. This can ultimately result in damage to the eyes, kidneys and other organs.

Cystinosis is transmitted in an autosomal recessive fashion and was the first genetic disorder to be identified among diseases that affect lysosomal transport [5]. The type of mutations present can affect the phenotypic expression of the disease. Mutations in the G197R and IVS10-3C-G CTS genes can be mild or severe, with the latter being associated with ocular non-nephropathic cystinosis. Mild mutations do not completely inhibit the production of CTS mRNA, permitting the transport of lysosomal cystine and decreasing the levels of cystine within the cell [6].

Infantile nephropathic cystinosis has an incidence of 1 case in 100,000 to 200,000 live births in North America [7], with estimations indicating that there are around 400 patients affected with cystinosis in the United States. Each year, 15 new cases are diagnosed in the United States alone.

Internationally, cystinosis has a wider prevalence in specific locations. In Brittany, for example, 1 of every 25,909 individuals suffers from the disease. Nonetheless, incidence in France in total is far less frequent with 1 case in every 326,440 individuals.

Cysteine is processed in the lysosome, where amino acids produced through the decomposition of ingested proteins are hydrolyzed in an acidic environment. Normally, cysteine undergoes an oxidization reaction and is converted to cystine and is then transported into the cytoplasm where it is re-transformed into cysteine with the help of reducing agents such as glutathione. Cytoplasmic cysteine can then be again inserted into a larger protein compound or it can undergo degradation and excretion outside the cell.

In cystinosis, cystinosin, the protein channel that is responsible for transporting cystine from the lysosome into the cytoplasm, is defective because of mutations that target the gene responsible for its expression. The end result is further accumulation of cystine within the lysosome, leading to the formation of various crystals that can be rectangular, birefringent or hexagonal.

Infantile nephropathic cystinosis is characterized by specific cystine crystal formation targeting kidney function, particularly in proximal tubular cells. Patients usually present between 6 and 12 months with a clinical phenotype corresponding to the Fanconi syndrome. This syndrome is known for salt and electrolyte wasting due to deficient absorption in the proximal tubule. The most commonly involved elements and compounds include magnesium, calcium, sodium, potassium, phosphate, bicarbonate and others. The resulting electrolyte imbalance and metabolic acidosis manifests clinically with growth abnormalities and is the most common form of Fanconi syndrome.

There are no current preventive measures for cystinosis.

Cystinosis is an inherited medical condition that results in an abnormal deposition of cystine in the various tissues and organs of the human body [1]. It is transmitted in an autosomal recessive fashion and results from mutations targeting the CTNS gene. This gene expresses a protein called cystinosin, that acts to transport cystine from the lysosome to the cytoplasm within the cell. A deficient cystine transporting channel leads to the abnormal formation of cystine crystals that can significantly damage cellular function. Cystinosis has a wide range of presenting symptoms, but is mostly characterized by kidney, ocular and growth abnormalities [2] [3]. Kidney dysfunction manifests with the Fanconi syndrome and can eventually lead to severe kidney failure and death if not treated. Ocular symptoms result from the deposition of cystine crystals within the cornea [4]. Treatment consists of medications that help deplete cells from cystine, kidney transplantation and various treatment options targeted specifically at symptomatic manifestations. For example, L-thyroxine is used for hypothyroidism, vitamin D and phosphate for rickets and insulin for insulin-dependent diabetes. Prognosis has markedly improved in the last four decades. With prompt and adequate treatment with cystine depleting drugs as well as kidney transplants, patients can expect to live up to their fifth decade of life.

Cystinosis is an inherited medical condition that results from the deposition of a particular organic compound called cystine. Excessive cystine can lead to the formation of crystals that ultimately disrupt the functioning of the cells and various organs. Cystinosis is transmitted in an autosomal recessive fashion. Normally, each individual has two copies of every gene, with each gene transmitted from one parent. A recessive genetic condition necessitates that mutations are present in both genes.

Cystinosis has various subtypes, although the most common and most severe subtype may present very early in childhood, by 10 months of age. Patients usually suffer from growth and ocular dysfunction as well as deterioration of the function of their kidneys. Variants that may present in adolescence or in early adulthood are much more benign and less likely to involve severe kidney dysfunction.

Treatment with medications such as cysteamine bitrate helps the body get rid of the excess cystine. Kidney transplantation may also be necessary to fully recover kidney function. Prognosis has significantly improved in the last four decades, and patients can now expect to live till their fifth decade.

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