| AIMS: To assess the involvement of the recently identified human homogentisate 1,2-dioxygenase gene (HGO) in alkaptonuria (AKU) in two unrelated patients with ochronosis of the conjunctiva, sclera, and cornea. methods: A mutation screen of the entire coding region of the HGO gene was performed using single stranded conformational analysis after polymerase chain reaction with oligonucleotide primers flanking all 14 exons of the HGO gene. Fragments showing aberrant mobility were directly sequenced. RESULTS: Two homozygous missense mutations, L25P and M368V, were identified, each of which leads to the replacement of a highly conserved amino acid in the HGO protein. CONCLUSIONS: The authors describe a novel mutation, L25P, in the German population and bring to 18 the total number of known HGO mutations. ( info) |
2/108. Hereditary ochronosis: hyperpigmented skin overlying cartilaginous structures. Hereditary ochronosis, or alkaptonuria, results from deficiency of homogentisic acid oxidase. It is an autosomal recessive condition found in geographically isolated populations. The excess homogentisic acid deposits in collagenous structures, leading to unusual pigmentation of the skin overlying cartilaginous structures, but on occasion pigment is also seen in the sclera, in sweat after oxidation, and classically, in urine when left standing at room temperature. This case report highlights the pathogenesis and expression of this rare disorder. ( info) |
3/108. Ochronotic arthropathy: case report and review of the literature. Alkoptonuria is an inherited metabolic disorder which is associated with various systemic abnormalities and related to the deposition of homogentisic acid pigment in connective tissues. These pigmentary changes are termed "ochronosis". We describe two patients with ochronotic arthropathy who presented with progressive and advanced degenerative changes in the lumbo-sacral spine. The literature, differential diagnosis and management of this rare condition are reviewed in this article. Management is usually conservative, but replacement surgery may be offered for severely affected major joints. ( info) |
4/108. Aortic stenosis in endogenous ochronosis. Endogenous ochronosis, a rare inherited disease of tyrosine metabolism, is caused by a deficiency of the enzyme, homogentisic acid oxidase, and may lead to cardiovascular involvement seen most frequently as aortic valve stenosis. We report the case of a patient with generalized ochronosis who developed cardiovascular symptoms due to aortic valve stenosis and who underwent aortic valve replacement. ( info) |
5/108. ochronosis: an unusual finding at aortic valve replacement. The condition known as ochronosis refers to the accumulation of oxidized homogentisic acid in the connective tissues of alkaptonuric patients. The diagnosis is usually made from the triad of degenerative arthritis, ochronotic connective tissue pigmentation and urine that turns dark brown or black on alkalinization. Cardiovascular disease is a less well appreciated aspect of this disorder. A patient with ochronosis of his stenotic aortic valve is reported. The role of the pigment in the genesis of the valve degeneration is discussed. ( info) |
6/108. chiropractic care and ochronotic arthropathy. OBJECTIVE: To discuss the case of a patient with ochronotic arthropathy whose symptoms were treated with chiropractic care. An emphasis is placed on this condition's radiographic features. CLINICAL FEATURES: A 59-year-old woman with pain in her low back, right knee, and left ankle sought chiropractic evaluation. Black pigmentation was found in the sclera of both eyes, and homogentisic acid was present in the urine. Orthopedic evaluation revealed uncomplicated, nonspecific joint pain, and radiographs demonstrated characteristic spinal changes. INTERVENTION AND OUTCOME: The patient was treated with chiropractic manipulation, physiotherapy modalities, bracing, and exercises. This type of therapy was successful in reducing the symptoms and helped decrease the severity and frequency of acute exacerbations. CONCLUSION: Ochronotic arthropathY is a rare metabolic disorder that can be diagnosed from spinal radiographs. chiropractic care is an appropriate tool for reducing its symptomatology. ( info) |
| minocycline, a derivative of tetracycline, is a broad spectrum antibiotic used in the treatment of gram-positive and gram-negative infections. Benitz et al. (1) were the first to report black discoloration of the thyroid gland in rats, dogs, and monkeys given minocycline. Since that time, there have been numerous reports in the literature describing minocycline related black pigmentation of the skin, thyroid gland, and other sites. We report an unusual case of minocycline induced pigmentation of the cardiac valves and coronary vessels. The pigment stained with Fontana-Masson and was reduced with bleaching. The exact nature of the pigment is unclear; however, various theories have been advocated. ochronosis is another cause of black pigmentation of the heart valves; the clinical history should allow distinction between the two. ( info) |
8/108. A morphological study of bone and articular cartilage in ochronosis. An ochronotic femoral head has been studied morphologically under the light and the electron microscope. Its articular cartilage showed the alterations already reported in the literature, mainly consisting of erosions of the surface, pigment accumulation in chondrocytes and intercellular matrix, chondrocyte degeneration, the formation of pigmented, calcified and uncalcified microshards, and the presence of granulation tissue with macrophagic cells. The changes in bone were less severe than those in cartilage. Pigment was present in the calcified matrix. This did not seem to disturb the organization of the bone tissue, although it was diffusely osteoporotic, perhaps because of limb disuse. The preservation of calcified matrix might depend on the fact that its collagen fibrils are encrusted by mineral substance, which avoids the dangerous effects that the deposition of ochronotic pigment induces in the fibrils of soft connective tissues. On the other hand, the newly formed osteoid matrix remains uncalcified for too short a time to be modified by the pigment. Diffuse or granular pigmentation was found in a few osteocytes, while several of them were condensed or reduced to cellular fragments. bone resorption often occurred near these osteocytes. However, this did not seem to alter the degree of bone remodelling, possibly because of the relatively low numbers of degenerated or dead osteocytes. Pigment was also contained in the cytoplasmic vacuoles of otherwise active osteoclasts, whereas it was not found in osteoblasts. On the whole, ochronosis in bone seems to induce the same changes as in other connective tissues. However, their severity appears to be limited by calcification, which prevents modifications in collagen fibrils, and by bone remodelling, which to some extent eliminates the oldest, pigment-richest parts of the tissue. ( info) |
| ochronosis is an uncommon condition characterized by yellow-brown pigment deposits in the dermis. It occurs in exogenous and endogenous forms. We report a case of exogenous ochronosis in a Hispanic woman and discuss the different forms of this condition. We treated the lesions with Q-switched ruby laser. ( info) |
10/108. Bilateral hip arthroplasty for ochronotic arthropathy. ochronosis is a musculoskeletal manifestation of alkaptonuria, a rare hereditary metabolic disorder characterised by the absence of the enzyme homogentisic acid oxidase and associated with various systemic abnormalities related to the deposition of homogentisic acid pigment (ochronotic pigment). In this report, we describe a 53-year-old, HLA-B27( ) woman with ochronotic arthropathy. In addition to the typical clinical features of the disorder, she had bilateral hip involvement, which was improved by cementless total hip prosthesis. ( info) |