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Joint replacement risk is markedly increased in alkaptonuria (AKU) in those with prior arthroplasty.Molecular Genetics and Metabolism... Sep 2024Increased homogentisic acid (HGA) in alkaptonuria (AKU) causes severe arthritis. Nitisinone reduces the production of HGA, but whether it also decreases arthroplasty was...
BACKGROUND
Increased homogentisic acid (HGA) in alkaptonuria (AKU) causes severe arthritis. Nitisinone reduces the production of HGA, but whether it also decreases arthroplasty was examined in 237 AKU patients.
PATIENTS AND METHODS
Patients attending the United Kingdom National Alkaptonuria Centre (NAC) and the Suitability of Nitisinone in Alkaptonuria 2 (SONIA 2) study were studied. Assessments included questionnaires eliciting details of arthroplasty. Nitisinone was administered from baseline, 2 mg in the NAC and 10 mg in SONIA 2. In SONIA 2, subgroups consisted of those with baseline arthroplasty on and not on nitisinone (BR + N+, BR + N-), as well as those without baseline arthroplasty on and not on nitisinone (BR-N+, BR-N-).
RESULTS
In the SONIA2 subgroups, new joint replacement (JR) probabilities after baseline were significantly different (BR + N+, BR + N-, BR-N+, BR-N-) (χ = 23.3, < 0.001); mean (SD) was 3.8 (0.1) years in BR-N-, 3.7 (0.1) years in BR-N+, 3.4 (0.3) years in BR + N-, and 3.0 (0.3) years in BR + N+. Further, the BR + N- showed more JR than the BR-N- subgroup ( < 0.01), while BR + N+ similarly showed more JR than the BR-N+ subgroup ( < 0.001).In the NAC, the BR- group had a mean age of 51.6 7.0) years at baseline but 57.7 (8.7) years at final follow up during nitisinone therapy and showed only 7 incident JR. The BR+ group had an age at baseline of 57.4 (8.5) years and had undergone 94 JRs at baseline.
CONCLUSION
The incidence of arthroplasty was earlier and more frequent after the first JR and was not affected by nitisinone.
PubMed: 38846518
DOI: 10.1016/j.ymgmr.2024.101097 -
Cureus Oct 2023Alkaptonuria is a rare genetic disorder characterized by the excessive production of homogentisic acid, leading to the formation and deposition of pigment polymers...
Alkaptonuria is a rare genetic disorder characterized by the excessive production of homogentisic acid, leading to the formation and deposition of pigment polymers throughout the body. It is extremely rare, affecting only around one in 100,000 individuals. Despite the normal life expectancy, it can cause severe morbidities. Alkaptonuria is typically managed supportively with pain medication, dietary modifications, and surgical interventions, which are considered to be the gold standard of therapy. Here we present a case of a 33-year-old male with no previous medical or surgical history who presented with severe acute back pain radiating to the left leg. Genetic testing confirmed a homozygous pathogenic variant for alkaptonuria. This case highlights the challenges in diagnosing alkaptonuria, emphasizing the significance of early detection, and clinical evaluation for improved outcomes. Furthermore, it underscores the need to consider alkaptonuria as a multidimensional disease, necessitating further research to enhance our understanding and develop effective management. Therefore, this study serves as an opportunity for future trials and studies aimed at digging deeper into the intricacies of alkaptonuria to increase our understanding and establish comprehensive management plans for affected individuals.
PubMed: 37937039
DOI: 10.7759/cureus.46644 -
International Journal of Molecular... Jul 2023Nitisinone has been approved for treatment of alkaptonuria (AKU). Non-invasive biomarkers of joint tissue remodelling could aid in understanding the molecular changes in... (Randomized Controlled Trial)
Randomized Controlled Trial
Nitisinone has been approved for treatment of alkaptonuria (AKU). Non-invasive biomarkers of joint tissue remodelling could aid in understanding the molecular changes in AKU pathogenesis and how these can be affected by treatment. Serological and urinary biomarkers of type I collagen and II collagen in AKU were investigated in patients enrolled in the randomized SONIA 2 (NCT01916382) clinical study at baseline and yearly until the end of the study (Year 4). The trajectories of the biomarkers over time were observed. After treatment with nitisinone, the biomarkers of type I collagen remodelling increased at Year 1 (19% and 40% increase in CTX-I and PRO-C1, respectively), which was potentially reflected in the higher degree of mobility seen following treatment. The biomarkers of type II collagen remodelling decreased over time in the nitisinone group: C2M showed a 9.7% decline at Year 1, and levels then remained stable over the following visits; CTX-II showed a 26% decline at Year 3 and 4 in the nitisinone-treated patients. Nitisinone treatment induced changes in biomarkers of bone and cartilage remodelling. These biomarkers can aid patient management and deepen our knowledge of the molecular mechanisms of this rare disease.
Topics: Humans; Alkaptonuria; Biomarkers; Cartilage; Collagen Type I
PubMed: 37446173
DOI: 10.3390/ijms241310996 -
Journal of Hand Surgery Global Online Jul 2023Alkaptonuria is a rare metabolic disorder characterized by the accumulation of homogentisic acid. Its effects on the central nervous system are well-recognized; however,...
Alkaptonuria is a rare metabolic disorder characterized by the accumulation of homogentisic acid. Its effects on the central nervous system are well-recognized; however, cases of pathologic homogentisic acid deposition in the peripheral nervous system are less well-described. We report the case of a 72-year-old man with a prior history of alkaptonuria presenting with bilateral carpal tunnel and left-sided cubital tunnel symptoms. This case is of note because the patient demonstrated a rapid onset of symptoms due to pathology at multiple foci.
PubMed: 37521546
DOI: 10.1016/j.jhsg.2022.10.018 -
Frontiers in Medicine 2023Ochronosis is a rare autosomal recessive disorder of tyrosine metabolism characterized by multilevel spinal degeneration and arthritis of large weight-bearing joints,...
Ochronosis is a rare autosomal recessive disorder of tyrosine metabolism characterized by multilevel spinal degeneration and arthritis of large weight-bearing joints, which is referred to as ochronotic arthropathy. In this case report, we describe diagnosis and treatment of ochronotic arthropathy in a patient who underwent total hip arthroplasty (THA) and total knee arthroplasty (TKA). The Harris hip score was 26 preoperatively and 45, 68, 76, 90, 92, and 94 at 1, 3, 6, 9, 11, and 14 months, respectively, postoperatively. The forgotten joint score (FJS) of the hip was 27.8, 52.8, 81.1, 89.0, 90.6, and 92.4 at 1, 3, 6, 9, 11, and 14 months, respectively, postoperatively. TKA was performed 8 months after THA. The Knee Society Score was 36 before TKA and 74, 82, and 90 at 1, 3, and 6 months, respectively, after TKA. The FJS of the knee was 36.6, 63.9, and 84.5 at 1, 3, and 6 months, respectively, after TKA. The patient's knee range of motion returned to normal, with significant reduction in pain and improved satisfaction levels after TKA. THA and TKA can achieve good clinical outcomes in patients with ochronosis accompanied by severe joint pain.
PubMed: 37795417
DOI: 10.3389/fmed.2023.1212580 -
Scientific Reports Sep 2023Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder caused by pathogenic variants in the homogentisate 1,2-dioxygenase (HGD) gene. This leads to a...
Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder caused by pathogenic variants in the homogentisate 1,2-dioxygenase (HGD) gene. This leads to a deficient HGD enzyme with the consequent accumulation of homogentisic acid (HGA) in different tissues causing complications in various organs, particularly in joints, heart valves and kidneys. The genetic basis of AKU in Egypt is completely unknown. We evaluated the clinical and genetic spectrum of six pediatric and adolescents AKU patients from four unrelated Egyptian families. All probands had a high level of HGA in urine by qualitative GC/MS before genetic confirmation by Sanger sequencing. Recruited AKU patients were four females and two males (median age 13 years). We identified four different pathogenic missense variants within HGD gene. Detected variants included a novel variant c.1079G > T;p.(Gly360Val) and three recurrent variants; c.1078G > C;p.(Gly360Arg), c.808G > A;p.(Gly270Arg) and c.473C > T;p.(Pro158Leu). All identified variants were properly segregating in the four families consistent with autosomal recessive inheritance. In this study, we reported the phenotypic and genotypic spectrum of alkaptonuria for the first time in Egypt. We further enriched the HGD-variant database with another novel pathogenic variant. The recent availability of nitisinone may promote the need for genetic confirmation at younger ages to start therapy earlier and prevent serious complications.
Topics: Adolescent; Female; Male; Humans; Child; Alkaptonuria; Egypt; Homogentisate 1,2-Dioxygenase; Phenylacetates; Homogentisic Acid; Dioxygenases
PubMed: 37658095
DOI: 10.1038/s41598-023-41200-7 -
Journal of Orthopaedic Case Reports Jun 2024Alkaptonuria is a rare autosomal recessive genetic disorder found in 2-5/million live births. It results in dark brown pigmentation of connective tissues including...
INTRODUCTION
Alkaptonuria is a rare autosomal recessive genetic disorder found in 2-5/million live births. It results in dark brown pigmentation of connective tissues including cartilage and joint capsule that can often lead to arthropathy of large joints. However, bone fractures are unusual. This article describes a fracture neck of the femur in a patient with undiagnosed alkaptonuria managed at a rural center.
CASE REPORT
A 60-year-old daily wage laborer with previously pain-free hips presented with sudden onset pain in the left hip while walking with no prior history of trauma. Radiographs showed a displaced fracture of the neck of the left femur. She underwent Left hip hemiarthroplasty. Intraoperatively, her soft-tissue including the joint capsule and the femoral head had dark brown pigmentation. Postoperatively, her urine was tested and the same turned black supporting the clinical diagnosis of alkaptonuria. At her 1-year follow-up, she had a painless, stable, and mobile hip.
CONCLUSION
We report a rare and unique case of neck of femur fracture in a patient with alkaptonuria treated with hemiarthroplasty in a resource-limited hospital in rural India. It is essential to consider the possibility of this condition when we come across a patient with an atypical fracture presentation. This article also presents an overview of alkaptonuria with a discussion on etiopathogenesis, clinical presentation, diagnosis, and management.
PubMed: 38910974
DOI: 10.13107/jocr.2024.v14.i06.4508 -
Journal of Bone Metabolism Aug 2023Alkaptonuria is an extremely rare autosomal recessive metabolic disorder characterized by dark urine, ochronosis, and arthritis of the spine and major joints. We report...
Alkaptonuria is an extremely rare autosomal recessive metabolic disorder characterized by dark urine, ochronosis, and arthritis of the spine and major joints. We report a case of ochronotic arthritis observed during total knee replacement surgery in a 65-year-old male patient with no relevant medical history. Based on a literature review, this is the first case of ochronotic arthritis reported in Korea.
PubMed: 37718906
DOI: 10.11005/jbm.2023.30.3.283 -
Journal of Orthopaedic Case Reports Dec 2023Alkaptonuria (AKU) is a rare autosomal-recessive multisystemic disease. It is caused by a mutant homogentisate dioxygenase coding gene, leading to the accumulation of...
INTRODUCTION
Alkaptonuria (AKU) is a rare autosomal-recessive multisystemic disease. It is caused by a mutant homogentisate dioxygenase coding gene, leading to the accumulation of homogentisic acid (HGA), hence systemic manifestations. Renal manifestations and tendon rupture are rarely reported.
CASE REPORT
We report a 60-year-old male with chronic kidney disease for over a decade who was initially misdiagnosed with ankylosing spondylitis and rheumatoid arthritis. Later on, the patient presented to our institute with a non-synchronized (8 years) acute quadriceps tendon rupture.
CONCLUSION
Physicians should be aware of the importance of prophylactic measures in the management of AKU, which is mainly medical management, to reduce the accumulation of HGA in the body. We further emphasize this point to reduce the incidence of subsequent tendon ruptures, as it significantly affects the quality of life.
PubMed: 38162369
DOI: 10.13107/jocr.2023.v13.i12.4088 -
European Heart Journal. Case Reports Feb 2024Alkaptonuria is a rare metabolic disease that causes an increase in homogentisic acid (HGA) due to a lack of enzymatic activity. Commonly, accumulation of HGA presents...
BACKGROUND
Alkaptonuria is a rare metabolic disease that causes an increase in homogentisic acid (HGA) due to a lack of enzymatic activity. Commonly, accumulation of HGA presents with dark discoloration of skin and other tissues, also known as ochronosis. Additionally, alkaptonuria can result in other clinical manifestations, including arthritis and cardiac disease. This case highlights alkaptonuria-related cardiac disease and challenges that cardiac surgery teams may face when treating this patient population.
CASE SUMMARY
A 62-year-old male with a history of alkaptonuria, Hodgkin's lymphoma treated with chemoradiation, hypertension, and hyperlipidaemia originally presented with shortness of breath in the setting of known cardiac disease. Cardiac work-up demonstrated aortic stenosis, mitral stenosis, and multivessel coronary artery disease requiring aortic valve replacement, mitral valve replacement, and coronary artery bypass grafting. During the operation, significant discoloration of tissue was observed. This correlated with areas of severe calcification, which was noted throughout both valves. Extensive debridement was required prior to proceeding to valve replacements. Additionally, near-infrared spectroscopy failed to provide accurate measurements of cerebral oxygenation.
DISCUSSION
Alkaptonuria is correlated with cardiovascular disease, particularly valvular disease. Intraoperatively, these patients may exhibit noticeable discoloration and severe calcification of various tissues. Additionally, traditional infrared-based methods of cerebral oxygenation monitoring may not be reliable; however, other options of cerebral monitoring may be feasible. With proper pre-operative planning, however, patients with alkaptonuria may safely undergo cardiac surgery.
PubMed: 38405194
DOI: 10.1093/ehjcr/ytae076