The objective of this research is to explore reported age related differences in toxicity of nitisinone and its pharmacokinetic underpinnings and to develop an optimal therapeutic requirement for a targeted population of presymptomatic patients...

The purpose of this study is to gain a better understanding of alkaptonuria and collect medical data on patients who may later participate in new drug trials for this rare genetic disease. In alkaptonuria, a pigment called homogentisic acid collects...

Follow Tony's blog: I’m at the National Institutes of Health this week to have a barrage of tests, the results of which will be added to the AKU knowledge base.

Eventually tests revealed Simon was suffering from a rare genetic condition called alkaptonuria (AKU) which causes homogentisic acid to build up in the body. The acid is expelled in the urine and changes to a dark colour a few hours after exposure to air. The condition is known as black bone disease.

Researchers have identified more than 100 new cases of the disease, called alkaptonuria (AKU) in a small community in Vellore, India, bringing the total number of patients there to 130.

Background : Ochronosis of alkaptonuria is a rare hereditary autosomal recessive disease in wich there is an absence of homogentisic acid oxidase resulting in accumulation of homogentisic acid in tissues. Aim: To report a new case of

Alkaptonuria is a rare autosomal recessive metabolic disorder characterized by a deficiency of homogentisate 1,2-dioxygenase (HGO) in the liver. This results in excretion of large quantities of homogentisic acid (HGA) (also called...

A 69-year-old woman presented with a 30-year history of lower back and large joint pain of the hips and shoulders. On examination blue-grey, pigmented macules were present over the cartilaginous portions of the ears and on the sclera....

Alkaptonuria (AKU) is due to excessive homogentisic acid accumulation in body fluids due to lack of enzyme homogentisate dioxygenase leading in turn to varied clinical manifestations mainly by a process of conversion of HGA to a..

A rare cause of valvular heart disease is the deposition of foreign material in the valvular tissues, including material accumulating as a result of inborn errors of metabolism of the essential amino acids. Alkaptonuria can result in...

This paper discusses strategies to identify individuals with the rare genetic disease alkaptonuria (AKU) within the general population. Strategies used included a questionnaire survey of general practitioners, a dedicated website and patient treatment since further barriers exist.//

Abstract

(Full text is available at http://www.manu.edu.mk/prilozi)

Conclusion: Clinicians should consider alkaptonuria in the differential diagnosis of patients with abnormal tympanic membrane pigmentation and hearing loss.

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We want to highlight the need of thorough preoperative evaluation in patients of alkaptonuria, as it is associated with multiple comorbidities. The systemic involvement should determine the anesthetic plan. Caution should be exercised during positioning to prevent injury to the joints and the spine.

Simon Laxon, who was diagnosed with a rare genetic disorder, alkaptonuria, soon after birth, describes his journey in understanding the condition and finding hope for a cure. 

Full text article via Springer publishers: This editorial is part of a review about the scientific heritage of rare human disorders and the genetic dissection of biochemical pathways.Alkaptonuria and other disorders of aromatic amino acid metabolism have a special place in this legacy. 

We believe that, currently, nuclear medicine techniques can provide useful information, which can be incorporated into disease severity scores for alkaptonuria. Once the biological basis for alkaptonuria is better understood, it is feasible that..

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Abstract
The cardiovascular manifestations of alkaptonuria relate to deposition of ochronotic pigment within heart valves, endocardium, aortic intima and coronary arteries. We assessed 16 individuals with alkaptonuria for cardiovascular disease, including full electrocardiographic and echocardiographic assessment....

Status: Recruiting, Condition Summary: Alkaptonuria

Abstract

This study was conducted to identify mutations in the homogentisate 1,2 dioxygenase gene (HGD) in alkaptonuria patients among Jordanian population. Blood samples were collected from four alkaptonuria patients, four carriers, and two healthy volunteers. DNA was isolated from peripheral blood. All 14 exons of the HGD gene were amplified using the polymerase chain reaction (PCR) technique. The PCR products were then purified and analyzed by sequencing. Five mutations were identified in our samples. Four of them were novel C1273A, T1046G, 551-552insG, T533G and had not been previously reported, and one mutation T847C has been described before. The types of mutations identified were two missense mutations, one splice site mutation, one frameshift mutation, and one polymorphism. We present the first molecular study of the HGD gene in Jordanian alkaptonuria patients. This study provides valuable information about the molecular basis of alkaptonuria in Jordanian population.

In pilot studies of the usefulness of solid state nuclear magnetic resonance spectroscopy in characterizing chemical and molecular structural effects of alkaptonuria on connective tissue, we have obtained (13) C spectra from articular cartilage...

Alkaptonuria (AKU) is an autosomal recessive disorder caused by a deficiency of homogentisate 1,2 dioxygenase (HGD) and characterized by homogentisic aciduria, ochronosis, and ochronotic arthritis. The defect is caused by mutations in...

Alkaptonuria is a rare, autosomal recessive disorder of tyrosine degradation due to deficiency of the third enzyme in the catabolic pathway. As a result, homogentisic acid (HGA) accumulates and is excreted in gram quantities in the urine, which turns dark upon alkalization. The first symptoms, occurring in early adulthood, involve a painful, progressively debilitating arthritis of the spine and large joints....

There are 7,000 rare diseases. AKU is just one of them, although it has a place in the history books for being the first metabolic disease ever identified, in 1901. This blog provides advice, tips and suggestions for the wider rare disease movement based on our experience on AKU. Please read on and don't hesitate to comment.

Summary

Disease characteristics. Alkaptonuria is caused by deficiency of homogentisate 1,2-dioxygenase, an enzyme that converts homogentisic acid (HGA) to maleylacetoacetic acid in the tyrosine degradation pathway. The three major features of alkaptonuria are the presence of HGA in the urine, ochronosis (bluish-black pigmentation in connective tissue), and arthritis of the spine and larger joints. Oxidation of the HGA excreted in the urine produces a melanin-like product and causes the urine to turn dark upon standing. Ochronosis occurs only after age 30 years; arthritis often begins in the third decade. Other manifestations include pigment deposition, aortic or mitral valve calcification or regurgitation and occasionally aortic dilatation, renal stones, and prostate stones.