Alkaptonuria
Symptoms
What are the main symptoms of Alkaptonuria?
There are three main symptoms of Alkaptonuria. Most occur only in adulthood. The first is HGA in the urine. This causes the urine to turn dark when it is exposed to air. However, darkening may not occur until several hours later. Many people with Alkaptonuria never notice this type of abnormal color to their urine. This may be the only noticeable sign in children.
The second symptom is called ochronosis. This is a term that means a person's connective tissue has a bluish-black color. This color is caused by a buildup of HGA in connective tissue. People can see this coloring in the white parts of their eyes, ear cartilage, and on the skin of their hands from underlying tendons. People with Alkaptonuria may also see this coloring in their ear wax and in their sweat.
The last symptom is arthritis. People with Alkaptonuria typically have arthritis in their spine and in their large joints from the buildup of HGA.
References
- Reference: Aquaron R. Alkaptonuria: a very rare metabolic disorder. Indian Journal Of Biochemistry & Biophysics. October 2013;50(5):339-344.
- http://www.ncbi.nlm.nih.gov/pubmed/24772955
More Symptoms Content
Are there earlier onset, later onset, or variant forms of Alkaptonuria?
What health problems should I look for in Alkaptonuria?
Are there any other diseases that look a lot like Alkaptonuria?
Is there one or two characteristic "odd" or "unusual" symptom or clinical feature of Alkaptonuria?
Is there variable expression or incomplete penetrance in Alkaptonuria?
Are there earlier onset, later onset, or variant forms of Alkaptonuria?
There are not different forms of Alkaptonuria. Many individuals with Alkaptonuria are typically asymptomatic and unaware of their condition until adulthood. Others were diagnosed because their parents noticed discolored urine in their diapers. All individuals with two changes in the HGD gene will have a buildup of HGA, ochronosis, and arthritis. Discolored urine is present from birth. Ochronosis is present around 30 years of age on average, and arthritis begins around 50 years of age on average.
References
- Aquaron R. Alkaptonuria: a very rare metabolic disorder. Indian Journal Of Biochemistry & Biophysics. October 2013;50(5):339-344.
- http://www.ncbi.nlm.nih.gov/pubmed/24772955
What health problems should I look for in Alkaptonuria?
Health problems associated with Alkaptonuria include:
- Arthritis of spine and larger joints
- Calcification of intervertebral ligaments (spine problem)
- Thickening of Achilles tendon, tendonitis and rupture
- 50% of people with Alkaptonuria develop renal (kidney) stones by 64 years of age
- Deposits of pigment into the heart can cause aortic or mitral valve calcification, regurgitation, or aortic dilation
- Prostate stones are common in men with Alkaptonuria, which may contribute to recurrent urinary tract infections or urinary obstruction
References
- http://www.ncbi.nlm.nih.gov/books/NBK1454/
- Introne WJ, Gahl WA. Alkaptonuria. 2003 May 9 [Updated 2016 May 12]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1454/
Are there any other diseases that look a lot like Alkaptonuria?
Some diseases that look like Alkaptonuria include:
- Ochronosis caused by prolonged use of chemical treatments. This type of ochronosis can be reversed. People with this type of ochronosis do not have high levels of HGA.
- Some Porphyria conditions such a acute intermittent porphyria cause discolored urine and may be mistaken for alkaptonuria.
- Arthritis caused by Alkaptonuria resembles another bone disorder (ankylosing spondylitis). Imaging studies can differentiate Alkaptonuria from this disorder as well as rheumatoid arthritis and osteoarthritis.
References
Is there one or two characteristic "odd" or "unusual" symptom or clinical feature of Alkaptonuria?
Unusual symptoms of Alkaptonuria include:
- Black urine
- Darkened connective tissue
- Arthritis
- Prostate stones
- Renal stones
- Darkened ear wax or sweat that stains clothing
References
- Aquaron R. Alkaptonuria: a very rare metabolic disorder. Indian Journal Of Biochemistry & Biophysics. October 2013;50(5):339-344.
- http://www.ncbi.nlm.nih.gov/pubmed/24772955
- Introne WJ, Gahl WA. Alkaptonuria. 2003 May 9 [Updated 2016 May 12]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1454/
Is there variable expression or incomplete penetrance in Alkaptonuria?
Every person with Alkaptonuria will have high levels of HGA in their urine, darkened connective tissue, and arthritis.
References
- Introne WJ, Perry MB, Troendle J, Tsilou E, Kayser MA, Suwannarat P, O'Brien KE, Bryant J, Sachdev V, Reynolds JC, Moylan E, Bernardini I, Gahl WA. A 3-year randomized therapeutic trial of nitisinone in alkaptonuria. Mol Genet Metab. 2011;103:307?14.
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3148330/
