Ochronotic involvement of the aortic and mitral valves in a 72-year-old man

Ochronosis, an autosomal recessive metabolic disorder, causes an excess of homogentisic acid that results in adverse pigmentation, calcification, and inflammation of cartilaginous and other tissues. Cardiovascular abnormalities are less frequently reported than are other manifestations. In rare cases, ochronosis can cause valvular heart disease. We report the case of a 72-year-old man with aortic stenosis and mitral insufficiency who was diagnosed with ochronosis while undergoing surgical aortic and mitral valve replacement. We discuss the history and surgical management of alkaptonuric ochronosis.

Aortic valve disease as a first manifestation of Alcaptonuria in surgically treated patient. Case report

BACKGROUND

Alcaptonuria, a rare metabolic disorder (1:250 000), is usually presented with symptoms such as arthropathies of weight bearing joints.

CASE REPORT

In this case, a 65 year old woman was admitted to our hospital with severe aortic stenosis and no other symptoms that would suggest the existance of Alcaptonuria. Intraoperative findings of black discoloration of the affected valve and ascending aorta, pointed towards the diagnosis of cardiac ochronosis, what was then confirmed by a PH examination.

CONCLUSION

This case suggests that although alcaptonuria is a slow progressive disease with cardiac ochronosis as a predictable late complication, it can nevertheless be a first sign. In that case the attention should be brought to the surely affected lumbar spine and weight bearing joints, and other connective tissue.

KEY WORDS

Alcaptonuria, Aortic valve, Cardiac ochronosis, Surgery.

An update on molecular genetics of Alkaptonuria (AKU)

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 the HGD gene, which maps to the human chromosome 3q21-q23. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups, but there are countries such as Slovakia and the Dominican Republic in which the incidence of this disorder rises to as much as 1:19,000. In this work, we summarize the genetic aspects of AKU in general and the distribution of all known disease-causing mutations reported so far. We focus on special features of AKU in Slovakia, which is one of the countries with an increased incidence of this rare metabolic disorder.

[Ochronosis: report of two familial cases]

BACKGROUND

Ochronosis of alkaptonuria is a rare hereditary autosomal recessive disease in which there is an absence of homogentisic acid oxidase resulting in accumulation of homogentisic acid in tissues.

AIM

To report a new case of alkaptonuria

CASE REPORT

A 49-year-old man had been followed for 4 years for chronic lombalgia and arthropaty of two knees. He is married to his cousin and father of 4 girls. His parents are also cousins. The clinical examination has found a cutaneuous pigmentation and a lumbar stiffness. At biological checking, creatininemia was at 190 μmol/L and there are not inflammatory indicators. The radiography have shown a discal dorsolumbar calcifications, anterior inter somatic bridges and bilateral arthritis of knees without articular chondrocalcinosis. The diagnosis of ochronosis have been suspected and confirmed by the blackness of urine and the dosage of alkaptonuria. The patient has been treated symptomatiquely. Familial investigation have revealed that his daughter suffered from the same disease with the notion of blackness of urine. She is 12 year old and she's asymptomatic on the osteoarticular level.

CONCLUSION

Alkaptonuria causes a degenerative arthropaty which can endanger functional prognosis. Early diagnosis and scanning of this innate error of metabolism by genetic study play a fundamental interest, especially for molecular and genetic advisement.

Degenerative arthritis of the knee secondary to ochronosis

Alkaptonuria is a rare disease in which a deficiency in the homogentisate 1, 2-dioxygenase enzyme results in a buildup of homogentisic acid. Ochronosis, the deposition of excess homogentisic acid in connective tissue, causes brownish-black pigmentation and weakening of the tissue ultimately resulting in chronic inflammation, degeneration, and osteoarthritis. There is currently no definitive cure for alkaptonuric ochronosis, and management is usually symptomatic. However, total joint replacements in severe cases of ochronotic osteoarthritis have comparable outcomes to osteoarthritic patients without ochronosis. We report a case of a patient with ochronotic arthritis of the knee treated with total knee arthroplasty.

Three-generational alkaptonuria in a non-consanguineous family

OBJECTIVE

Alkaptonuria (AKU) is a rare inborn error of metabolism of aromatic amino acids and considered to be an autosomal recessive trait caused by mutations in the homogentisate 1,2-dioxygenase (HGD) gene. A dominant pattern of inheritance has been reported but was attributed to extended consanguinity in many cases. However, we have observed a non-consanguineous family segregating AKU in a dominant manner over three generations.

RESULTS

All affected individuals presented with typical features of AKU including darkening of the urine, ochronosis, arthropathy, and elevated urinary excretion of homogentisic acid. Sequence analysis of the HGD gene from genomic DNA of two affected individuals, uncle and niece, revealed a heterozygous missense mutation (M368V) in the uncle that was not present in his niece. Microsatellite genotyping demonstrated that both were heterozygous at the HGD locus and shared one haplotype. This haplotype did not contain a detectable HGD mutation. The haplotype was also found in a healthy son of the niece, making a dominant HGD mutation unlikely. Moreover, sequencing of cDNA from lymphoblastoid cells of the niece did not reveal an HGD mRNA with a potentially dominant-negative effect.

CONCLUSION

Rare causes of the uncommon AKU inheritance in this family have to be considered, ranging from the coincidence of undetectable HGD mutations to a dominant mutation of a second, hitherto unknown AKU gene.

Coexistence of ochronosis and B 27 positive ankylosing spondylitis

We describe a 49-year-old man with coexistence of ochronosis and B27 positive ankylosing spondylitis. This is the first report documenting the simultaneous occurrence of ochronosis and B27 positive ankylosing spondylitis, with no positive familiar history for seronegative spondylarthropathies. The relations of these rheumatic diseases are discussed.

Alkaptonuria, ochronosis, and ochronotic arthropathy

OBJECTIVES

To describe the clinical presentation and course of a relatively large group of Italian adult patients screened for mutation of the homogentisate dioxygenase gene causing alkaptonuria (AKU) and ochronosis, and to review typical and atypical facets of this condition.

METHODS

We reviewed the medical records of 9 patients affected by ochronotic arthropathy who were observed in our institutions between 1979 and 2001. All patients were diagnosed as having AKU through a rapid urine test with alkali. Mutation screening was performed by single-strand conformation analysis of all homogentisate dioxygenase exons, followed by sequencing of altered conformers.

RESULTS

Our 9 cases had similar clinical features and they reflected those described in the literature: a progressive degenerative arthropathy mainly affecting axial and weight-bearing joints associated with extraarticular manifestation. Musculoskeletal symptoms began in most of our patients around the age of 30 years with back pain and stiffness: involvement of the large peripheral joints usually occurred several years after spinal changes. Ochronotic peripheral arthropathy generally was degenerative, but joint inflammation was observed in some cases; this could be attributed to an inflammatory reaction of the ochronotic shard in the synovial membrane.

CONCLUSIONS

Ochronosis is a model of arthropathy with known etiologic factors. Over time, AKU, the genetically determined metabolic defect, leads to the accumulation of pigment and the development of this crippling condition. Most of the clinical findings may be explained by inhibition of collagen crosslinks, but some require additional interpretation. For example, inflammatory features of the ochronotic joint only occur in a minority of cases, and may be attributable to ochronotic shards. Further studies are needed to establish the genotype-phenotype correlation to identify mutations that are predictive of severe disease. For this purpose, the Italian Study Group on Alkaptonuria (www.dfc.unifi.it/aku) is enrolling affected patients in an on-line database to characterize the molecular defects and their relationship to clinical data.

Ochronotic arthropathy

The authors report on 18 members of four generations of an alkaptonuric family. All three males in the third generation are clinically affected; two members of the family tree have undergone major joint surgery.

Alkaptonuria caused by compound heterozygote mutations

Alkaptonuria is a rare autosomal recessive disorder of inborn errors of metabolism. It is characterised by the deposition of "ochronotic pigment" especially in connective tissue as a result of deficieny of the "homogentisic acid oxidase" enzyme which has a role in the catabolism of tyrosine and phenylalanine. A compound heterozygote alkaptonuria patient, with manifestations in adulthood, without infantile and childhood signs is presented. The described alkaptonuria mutations are reported for the first time in the Turkish population.

Aortic valve stenosis in alkaptonuric ochronosis

Alkaptonuria is a rare genetic disorder of tyrosine metabolism in which a bluish pigment accumulates in the connective tissues throughout the body, and causes degenerative changes. The most common clinical manifestation of ochronosis is arthropathy. Heart valves may also be affected, though cardiac involvement is rare. The present patient has cardiac ochronosis, and has several family members diagnosed with ochronosis and aortic valve stenosis.

[Diagnostic image (45). Ochronosis]

In a 70-year-old woman, in whom ochronosis (alkaptonuria) was diagnosed at the age of 54, bluish discolouration of the cartilage of the ears was observed.

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.

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.

Ocular ochronosis in alkaptonuria patients carrying mutations in the homogentisate 1,2-dioxygenase gene

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.

[Concomitant manifestation of ochronosis and chronic polyarthritis in a patient]

Ochronosis is rare disorder of tyrosin catabolism with an autosomal, recessive trait. Clinical signs predominantly affect the locomotor system. Inflammatory episodes in large joints can mimick Rheumatoid Arthritis (RA). Brownish discoloration of sclerae and cartilage is characteristic, diagnosis is confirmed by typical changes of spinal X-rays and the findings of homogentisic acid in urine samples. We describe a case of a 53 year old female patient with ochronosis and a second diagnosis of RA.

Alkaptonuric ochronosis: report of two affected brothers

Alkaptonuric ochronosis is a rare inborn metabolic disorder. Because of the deficient activity of the enzyme homogentisic acid oxidase, homogentisic acid accumulates in plasma, is deposited in various tissues and is excreted in large amounts in urine. Dark brown discoloration of urine on exposure to air or after addition of alkaline solution is characteristic. We describe two brothers with typical alkaptonuric ochronosis with dark urine, blue pigmentation of auricles and axillae, focal brown hyperpigmentation of sclerae, and anthropathy.

Ochronotic arthropathy: the black hip. Case report and review of the literature

Ochronosis is the dark pigmentation of connective tissues in patients with alkaptonuria. The latter is an autosomal recessive deficit of phenylalanine and tyrosine metabolism with various clinical manifestations. We report on a 63-year-old man with familial ochronosis, who presented with a terminal degenerative right hip joint; his older brother had already been successfully treated at our department by total hip replacement. The postoperative course was uneventful and satisfactory for both.

Familial ochronosis

We report the case of a 72-year-old female with alkaptonuric ochronosis and symptomatic aortic stenosis requiring aortic valve replacement. She was the seventh of nine children, and four of the nine siblings were diagnosed as having ochronosis. Only one, however presented with aortic stenosis.

[A rare case of high dorsal radicular-medullary compression in a patient with ochronotic arthropathy. Clinico-radiological features]

Alkaptonuria is a rare, hereditary, metabolic disease in which homogentisic acid, an intermediary product in the metabolism of phenylalanine and tyrosine, cannot be further metabolized. The metabolic defect causes a characteristic triad of homogentisic aciduria, ochronosis, and arthritis. The cause of this disease is a constitutional lack of the enzyme homogentisic acid oxidase. The condition is inherited as an autosomal recessive disease. The ochronotic arthritis affects mainly male subjects after fourty. Authors present a case of a 60 years old man suffering from a generalized ochronotic arthritis since 1976. From 1992 summer to the beginning of 1993 the patient developed a progressive weakness in the lower limbs associated with thoracic back pain and subsequently a spastic paraparesis. These symptoms were related to a vertebral compression due to D4-D5 pathologic fracture. In spite of a decompressive operation the neurologic symptoms didn't improve.

[Alkaptonuria and ochronotic arthropathy. Arthroscopic and intraoperative findings in implantation of a knee joint surface replacing prosthesis]

Alcaptonuria is a rare (incidence approx. 1:10(6)), autosomal-recessive transmitted metabolic disease. The basic defect is a lack of the enzyme homogentisic acid oxidase. During metabolism of phenylalanin and tyrosin to fumaric acid and acetoacetic acid this enzymatic defect causes an accumulation of the intermediate breakdown product homogentisic acid in bradytrophic tissues resulting in pigmentation and calcification of the intervertebral disks. We present a 57 year old female patient in whom we diagnosed alcaptonuria by the appearance of the typical symptom trias homogentisic acid excretion in the urine, ochronosis and arthritis. The anamnesis and results of a knee arthroscopy, radiographic and laboratory examinations as well as the intraoperative and histological findings during implantation of a knee joint surface replacing prosthesis (Gemini-System, Link Co., Hamburg, Germany) are reported.

Coexistence of ochronosis and rheumatoid arthritis

We describe a 64-year-old female patient with ochronosis and rheumatoid arthritis. Magnetic resonance imaging of the spinal column disclosed the destruction of vertebral disks, and a bony bridging in Th12 to L2. In addition, we observed joint space narrowing in the wrists as well as among the carpal bones, positive rheumatoid factor and the presence of rheumatoid nodules, in which the histological findings were compatible with those of rheumatoid arthritis. The co-existence of these two diseases has not yet been previously reported. Pre-existing ochronotic arthropathy might have masked the manifestation of rheumatoid arthritis and made the diagnosis of rheumatoid arthritis rather difficult.

[Alkaptonuria-ochronosis]

The authors describe the case of a 40-year old female patient. Since her childhood she realised of her urine the black discoloration of the underwear. For about a year, without subjective complaints, blue-black color of the skin involved the axillae and pinnae. For a year appeared the increased pain of thoracal and lumbal spine column and the limitation of motion of these parts. The examination of urine, histological and electron microscopical findings, the X-ray photograph of the spinal column confirmed the diagnosis of alkaptonuria or rather congenital ochronosis.

Alkaptonuria and ochronosis in three siblings. Ascorbic acid treatment monitored by urinary HGA excretion

Patients with alkaptonuria lack homogentisate 1,2-dioxygenase leading to retention of homogentistic acid (HGA) in body fluids and eventually to tissue deposition of oxidation products, giving rise to the clinical picture of ochronosis. Ascorbic acid is a known inhibitor of the enzyme which catalyses the oxidation of homogentisic acid (HGA) to the polymer with affinity for collagen and was used in the treatment of three siblings with alkaptonuria. Ascorbic acid 500 mg bid was administered for 12 months. Two of the siblings tolerated the treatment, and in one the symptoms improved, whereas in the other they worsened. Plasma and urinary levels of HGA were monitored with a new HPLC method. Ascorbic acid is not effective in the treatment of symptomatic ochronosis.

Low back pain and ochronosis

We have examined the presentation of low back pain in three patients with ochronosis, and have reviewed the literature. Low back pain and/or stiffness is the first presenting feature and usually appears after the age of 30. Discolouration of the ear is almost always present. Characteristic radiographic changes in the lumbar spine include calcification of the intervertebral discs and lucencies in the discs. The process gradually extends to the entire spine.

Alkaptonuria and ochronosis. A survey and 5 cases

A survey of alkaptonuria and ochronosis is given, based on the literature and on 5 additional cases. The disease, which is autosomal recessive, results from a decreased amount of the enzyme homogentisic acid oxidase, due to which tyrosine and phenylalanine cannot be broken down via the normal pathway. The diagnosis is made by determination of urinary urinary homogentisic acid excretion, as the clinical and radiological findings are not pathognomonic. The symptoms, which extend over decades, result from the deposition of pigment in the extracellular macromolecules of the connective tissue, particularly of the skin and joints.

Tendon involvement in a case of ochronosis

A patient with severe skeletal and systemic involvement due to ochronosis is reported. On radiographic examination there was a linear density attached to the left lesser trochanter. The possible role of ochronotic pigment deposition in tendon, leading to metaplastic bone formation, is discussed.

[HLA-B27 antigen and alkaptonuria]

Study of urinary homogentisic acid and a determinantion of group HLA were carried out for 36 members of a family spread over three generations with three cases of ochronotic rheumatism in the second generation. Alkaptonuria was discovered in seven other subjects, six of them members of the third generation: urinary elimination was poor, less than 0.60 g/24 hours. There is a certain degree of consanguinity in the family studied here and these findings do not therefore rule out a recessive autosomal transmission of the alkaptonuria. They do however lead to the consideration that alkaptonuria may sometimes be found in heterozygotic subjects. A genetic relationship between HLA complex and alkaptonuria can only be claimed with difficulty from this familial study, but the high frequency of B 27 antigen (29 out of 36 members carring it) leaves room for the hypothesis that the B 27 gene, or more precisely a gene associated with the B 27 gene, plays a part in the development of ochronotic rheumatism.