ABSTRACT
Pulmonary hypertension (PH) can be diagnosed in the context of connective tissue diseases (CTD) as well as in elderly patients with multiple comorbidities. A correct clinical differential diagnosis and classification is essential before adequate therapeutic decisions can be made. Differential diagnosis of PH in CTD comprises associated pulmonary arterial hypertension (APAH), group 2 or 3 PH (PH arising from left heart or chronic lung disease), chronic thromboembolic PH (PH) and group 5 (e.âg. in the context of terminal renal insufficiency). This is also true of elderly patients in whom the decision has to be made if the increasing number of coincident diseases lead to PH or have to be interpreted as comorbidities. In this manuscript, the differential diagnosis of PH is elucidated, focusing on CTD, in the context of left heart disease and chronic lung disease. Furthermore, criteria are presented facilitating an objective approach in this context.
Subject(s)
Diagnosis, Differential , Heart Diseases , Hypertension, Pulmonary , Lung Diseases/diagnosis , Connective Tissue Diseases/complications , Connective Tissue Diseases/diagnosis , Heart Diseases/diagnosis , Humans , Hypertension, Pulmonary/diagnosisABSTRACT
At the 6th World Symposium on Pulmonary Hypertension (WSPH), which took place from February 27 until March 1, 2018 in Nice, scientific progress over the past 5 years in the field of pulmonary hypertension (PH) was presented by 13 working groups. The results of the discussion were published as proceedings towards the end of 2018.âOne of the major changes suggested by the WSPH was the lowering of the diagnostic threshold for PH from ≥â25 to >â20âmmHg mean pulmonary arterial pressure, measured by right heart catheterization at rest. In addition, the pulmonary vascular resistance was introduced into the definition of PH, which underlines the importance of cardiac output determination at the diagnostic right heart catheterization.In this article, we discuss the rationale and possible consequences of a changed PH definition in the context of the current literature. Further, we provide a current overview on non-invasive and invasive methods for diagnosis, differential diagnosis, and prognosis of PH, including exercise tests.
Subject(s)
Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/therapy , Practice Guidelines as Topic/standards , Cardiac Catheterization , HumansABSTRACT
When caring for patients with respiratory diseases, always think of the heart! This is especially important for COPD patients, but also for a variety of other disorders of the respiratory system. At the workshop "Luftschlösser", held once more at Wiesbaden, Germany in February 2019 the many and important interactions of the lungs and the heart as well as the therapeutic implications were discussed. Based on pathophysiology, the psycho-social consequences of dyspnea, the leading symptom in patients with lung and heart disease became apparent. A particularly demanding diagnostic and therapeutic situation occurs in patients suffering simultaneously of lung and heart disease. It has been shown how frequently the diagnosis myocardial infarction is missed in COPD patients - and vice versa. Surprisingly, this is also the case in asthmatics with coronary heart disease or heart failure, a fact not readily known in clinical practice. In patients with emphysema and no apparent heart disease, hyperinflation leads to significantly restricted heart function. Reducing hyperinflation by inhaling broncholytics thus improves heart function. Biomarkers are increasingly being used for diagnostic purposes. Their role is being investigated in the large German COPD cohort COSYCONET. Lung patients suffering from more severe heart diseases pose a challenge for therapy in intensive care, especially when ventilated, and weaning from the ventilator is prolonged. Lung vessel diseases are "classic" examples of the intimate interaction of the lungs and the heart. In pulmonary arterial hypertension as well as in chronic thrombo-embolic pulmonary hypertension the lag time between the first symptoms and the definite diagnosis is often unacceptably long. For both diseases of the lung vessels therapeutic options have improved significantly over the last years. Pulmonologists should take care of this increasingly important patient group. Sleep-related breathing disorders and heart function are closely intertwined. Both conditions need special attention after the results of the SERVE-HF trial have been published. But there is no doubt that obstructive sleep apnea represents an independent and important risk factor for cardiovascular disease and needs to be treated according to existing guidelines.This workshop demonstrated impressively the multiple interactions of the respiratory system with cardiac function, resulting diagnostic and therapeutic problems, and means to overcome these problems. Guidelines for respiratory diseases should appropriately address cardiac comorbidity.
Subject(s)
Heart Failure/physiopathology , Lung/physiopathology , Pulmonary Disease, Chronic Obstructive/physiopathology , Comorbidity , Dyspnea/epidemiology , Germany/epidemiology , Heart Failure/complications , Heart Failure/epidemiology , Humans , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/epidemiologyABSTRACT
Exertional dyspnea is a nonspecific symptom with a variety of underlying causes. It can be challenging to differentiate a beginning cardiac disease from a pulmonary disease or from deconditioning alone. In the presence of obesity, the overall assessment is even more difficult. Rare diseases, such as pulmonary hypertension with dyspnea on exertion as the cardinal symptom are usually diagnosed late in the course of disease. The starting point of a successful evaluation is a thorough patient history. The combination of symptoms, clinical signs and findings leads to a preferred differential diagnosis. Readily available basic findings, such as physical examination, electrocardiogram (ECG), spirometry and laboratory tests help with the diagnosis. For unexplained causes, extended diagnostics such as echocardiography, blood gas analysis and finally special examinations are available. Cardiopulmonary exercise testing (CPET) and exercise echocardiography as well as right heart catheterization at rest and during exercise in the hands of experienced physicians allow an exact differentiation.
Subject(s)
Dyspnea , Heart Diseases , Hypertension, Pulmonary , Dyspnea/diagnosis , Dyspnea/therapy , Electrocardiography , Exercise Test , Heart Diseases/complications , Heart Diseases/diagnosis , HumansABSTRACT
Cystic Fibrosis (CF) is the most common autosomal-recessive genetic disease affecting approximately 8000 people in Germany. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the epithelial lining fluid which leads to chronic inflammation of the airways. Recurrent infections of the airways as well as pulmonary exacerbations aggravate chronic inflammation, lead to pulmonary fibrosis and tissue destruction up to global respiratory insufficiency, which is responsible for the mortality in over 90â% of patients. The main aim of pulmonary treatment in CF is to reduce pulmonary inflammation and chronic infection. Pseudomonas aeruginosa (Pa) is the most relevant pathogen in the course of CF lung disease. Colonization and chronic infection are leading to additional loss of pulmonary function. There are many possibilities to treat Pa-infection. This is a S3-clinical guideline which implements a definition for chronic Pa-infection and demonstrates evidence-based diagnostic methods and medical treatment for Pa-infection in order to give guidance for individual treatment options.
Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis/diagnosis , Cystic Fibrosis/therapy , Practice Guidelines as Topic , Pseudomonas aeruginosa/isolation & purification , Cystic Fibrosis/complications , Cystic Fibrosis/microbiology , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Germany , Humans , Pseudomonas Infections/diagnosisABSTRACT
The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. The guidelines contain detailed information about the clinical classification and diagnosis of pulmonary hypertension, and furthermore provide novel recommendations for risk stratification and follow-up assessments. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the clinical classification and initial diagnosis of PH. This article summarizes the results and recommendations of this working group.
Subject(s)
Blood Pressure Determination/standards , Cardiology/standards , Hypertension, Pulmonary/diagnosis , Practice Guidelines as Topic , Pulmonary Medicine/standards , Terminology as Topic , Early Diagnosis , Germany , Humans , Hypertension, Pulmonary/classificationABSTRACT
The 2015 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH) but also some aspects of pulmonary hypertension (PH) associated with chronic lung disease. The European Guidelines point out that the drugs currently used to treat patients with PAH (prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, sGC stimulators) have not been sufficiently investigated in other forms of PH. Therefore, the European Guidelines do not recommend the use of these drugs in patients with chronic lung disease and PH. This recommendation, however, is not always in agreement with medical ethics as physicians feel sometimes inclined to treat other form of PH which may affect quality of life and survival of these patients in a similar manner. To this end, it is crucial to consider the severity of both PH and the underlying lung disease. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany, to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. Several working groups were initiated, one of which was dedicated to the diagnosis and treatment of PH in patients with chronic lung disease. The recommendations of this working group are summarized in the present paper.
Subject(s)
Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/therapy , Lung Injury/complications , Lung Injury/therapy , Practice Guidelines as Topic , Pulmonary Medicine/standards , Cardiology/standards , Germany , Humans , Hypertension, Pulmonary/diagnosis , Lung Injury/diagnosisABSTRACT
The 2015 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH), but also other significant subgroups of pulmonary hypertension (PH). In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. Several working groups were initiated, one of which was dedicated to the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (CTEPH). In every patient with PH of unknown cause CTEPH should be excluded. The primary treatment option is surgical pulmonary endarterectomy (PEA) in a specialized multidisciplinary CTEPH center. Inoperable patients or patients with persistent or recurrent CTEPH after PEA are candidates for targeted drug therapy. For balloon pulmonary angioplasty (BPA), there is currently only limited experience. This option - as PEA - is reserved to specialized centers with expertise for this treatment method. In addition, a brief overview is given on pulmonary artery sarcoma, since its surgical treatment is often analogous to PEA. The recommendations of this working group are summarized in the present paper.
Subject(s)
Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/therapy , Practice Guidelines as Topic , Pulmonary Embolism/diagnosis , Pulmonary Embolism/therapy , Pulmonary Medicine/standards , Antihypertensive Agents/administration & dosage , Cardiology/standards , Drug Therapy, Combination/standards , Fibrinolytic Agents/administration & dosage , Humans , Hypertension, Pulmonary/etiology , Molecular Targeted Therapy/standards , Pulmonary Embolism/complicationsABSTRACT
Dyspnoea is the predominant symptom in patients with pulmonary hypertension (PH) at diagnosis. However, since dyspnoea is nonspecific and often occurs in a number of common diseases, the presence of PH can easily be underdiagnosed.In addition, this symptom underlies a high variability in the subjective perception, therefore further diagnostic procedures are often delayed by the patients.A survey of the incidence and severity of dyspnoea in 372 patients with PAH was conducted by questionnaire in German centres. Age, sex distribution and the range of comorbidities corresponded to the findings of national and international registries.Approximately 99â% of patients reported the presence of dyspnoea on exertion, even at low loads.Remarkably, in 13â% of patients dyspnoea occurs as a paroxysmal symptom, which may lead to the differential diagnosis of bronchial asthma. In addition, the patients who were being followed in specialized PH centres reported an increase in dyspnoea during the last year.The results of the survey on the incidence of dyspnoea in patients with PAH are consistent with the findings of international studies.
Subject(s)
Dyspnea/diagnosis , Dyspnea/epidemiology , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/epidemiology , Adult , Age Distribution , Aged , Aged, 80 and over , Comorbidity , Female , Germany/epidemiology , Health Care Surveys , Humans , Incidence , Male , Middle Aged , Respiratory Care Units/statistics & numerical data , Respiratory Center , Risk Assessment , Sex Distribution , Young AdultABSTRACT
In this work the structural and morphological changes of Ce1-xPrxO2-δ (x = 0.20, 0.35 and 0.75) films grown on Si(111) due to post deposition annealing are investigated by low energy electron diffraction combined with a spot profile analysis. The surface of the oxide films exhibit mosaics with large terraces separated by monoatomic steps. It is shown that the Ce/Pr ratio and post deposition annealing temperature can be used to tune the mosaic spread, terrace size and step height of the grains. The morphological changes are accompanied by a phase transition from a fluorite type lattice to a bixbyite structure. Furthermore, at high PDA temperatures a silicate formation via a polycrystalline intermediate state is observed.
ABSTRACT
Riociguat is the first clinically available soluble Guanylate-cyclase stimulator (sGC) and representative of a completely new class of drugs. Riociguat is approved for pulmonary arterial hypertension (PAH) and non-operable or recurrent/persistent chronic thromboembolic pulmonary hypertension (CTEPH). Moreover, Riociguat is currently under investigation for a wider spectrum of diseases. This article focusses on its mode of action and clinical trial data. Finally, based on these data, the status of approval, as well as the costs a proposal is given how Riociguat can be integrated in the current treatment of PAH and CTEPH.
Subject(s)
Guanylate Cyclase/metabolism , Hypertension, Pulmonary/drug therapy , Hypertension, Pulmonary/metabolism , Pulmonary Embolism/drug therapy , Pulmonary Embolism/metabolism , Pyrazoles/administration & dosage , Pyrimidines/administration & dosage , Receptors, Cytoplasmic and Nuclear/metabolism , Antihypertensive Agents/administration & dosage , Chronic Disease , Fibrinolytic Agents/administration & dosage , Humans , Hypertension, Pulmonary/complications , Pulmonary Embolism/complications , Pyrazoles/pharmacokinetics , Pyrimidines/pharmacokinetics , Receptors, Cytoplasmic and Nuclear/agonists , Soluble Guanylyl Cyclase , Treatment OutcomeSubject(s)
Hypertension, Pulmonary/psychology , Pulmonary Embolism/psychology , Quality of Life/psychology , Chronic Disease , Humans , Hypertension, Pulmonary/therapy , Patient Satisfaction , Pulmonary Embolism/therapy , Randomized Controlled Trials as Topic , Surveys and Questionnaires , Treatment OutcomeSubject(s)
Benzamides/therapeutic use , Hypertension, Pulmonary/drug therapy , Piperazines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Benzamides/adverse effects , Germany , Humans , Hypertension, Pulmonary/mortality , Imatinib Mesylate , Off-Label Use , Piperazines/adverse effects , Protein Kinase Inhibitors/adverse effects , Pyrimidines/adverse effects , Randomized Controlled Trials as Topic , Survival Rate , Ventricular Dysfunction, Right/drug therapy , Ventricular Dysfunction, Right/mortalitySubject(s)
Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/therapy , Pulmonary Embolism/diagnosis , Pulmonary Embolism/therapy , Angioplasty, Balloon , Anticoagulants/administration & dosage , Chronic Disease , Endarterectomy , Follow-Up Studies , Humans , Hypertension, Pulmonary/mortality , Long-Term Care , Pulmonary Embolism/mortality , Survival RateABSTRACT
This position paper summarises current developments in chronic thromboembolic pulmonary hypertension (CTEPH) including diagnostic approaches and treatment options. Based on the guidelines of the task force of CTEPH experts at the 5th World Symposium on Pulmonary Hypertension in Nice 2013. Open questions arising during the treatment of patients with CTEPH are addressed. Patients with suspected CTEPH should undergo echocardiography and cardiopulmonary exercise testing. A ventilation/perfusion scan is the recommended imaging test for screening in the diagnostic algorithm for the evaluation of CTEPH. CTEPH-patients should be discussed in an expert center with an interdisciplinary team and an experienced PEA surgeon to decide the further treatment. Pulmonary endarterectomy (PEA) is the treatment of choice for patients with CTEPH. Medical therapy with PH-targeted medications for inoperable CTEPH and residual disease after PEA should only be initiated if evaluation reveals that the patient is no candidate for a PEA. Current data suggest that CTEPH patients treated with PEA have a better long-term survival rate and quality of life than patients treated with medical therapy.
Subject(s)
Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/therapy , Pulmonary Embolism/diagnosis , Pulmonary Embolism/therapy , Algorithms , Chronic Disease , Combined Modality Therapy , Cooperative Behavior , Echocardiography , Endarterectomy , Exercise Test , Humans , Hypertension, Pulmonary/mortality , Hypertension, Pulmonary/physiopathology , Interdisciplinary Communication , Mass Screening , Molecular Targeted Therapy , Practice Guidelines as Topic , Prognosis , Pulmonary Artery , Pulmonary Embolism/mortality , Pulmonary Embolism/physiopathology , Survival Rate , Tertiary Care Centers , Ventilation-Perfusion Ratio/physiologyABSTRACT
BACKGROUND AND AIM: Chronic-thromboembolic pulmonary hypertension (CTEPH) is a serious complication of acute pulmonary embolism (PE). In untreated patients prognosis is poor. It depends on WHO-functional class. A delay from onset of symptoms and diagnosis can lead to a further worsening of prognosis. A pulmonary endarterectomy is the treatment of choice. We aimed to evaluate the time delay from onset of symptoms to diagnosis and the WHO-functional class at primary diagnosis in patients with CTEPH. PATIENTS AND METHODS: Retrospective analysis of data from 70 monocentrically registered patients (48 women, 22 men, mean age 66,2 yearsâ ± â13,8 years) with confirmed CTEPH from the pulmonary hypertension expert center Missionsärztliche Klinik. Diagnostic work-up was performed according to the current guidelines. RESULTS: Mean delay from onset of symptoms to diagnosis of CTEPH was 18â±â26 months. Time delay was only slightly shorter in patients with a history of PE (nâ=â56; 81â%) than in patients without a history of PE (nâ=â13; 19â%): 16,9â ± â23,8 vs. 23,5 â± â36,9 months. Time delay was higher in patients who received vasoactive medication before the first contact with a PH expert center and in patients who were classified as technically not suitable for a thrombendarterectomy. 38 patients with a history of acute PE did not have a period without symptoms. In 18 patients symptoms had transiently gone after PE. More than 70â% presented in WHO functional class III or IV. CONCLUSION: Time delay between onset of symptoms and diagnosis of CTEPH and referral to a PH expert center is long and the majority of patients presented in WHO-functional class III or IV. Prognosis is poor in untreated patients and getting worse with a higher WHO-functional class. For this reason, and because CTEPH can be cured by a pulmonary endarterectomy, each patient with suspected PH should be referred to a PH expert center to exclude CTEPH.
Subject(s)
Delayed Diagnosis , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/surgery , Pulmonary Embolism/diagnosis , Pulmonary Embolism/surgery , Aged , Algorithms , Chronic Disease , Cooperative Behavior , Embolectomy , Endarterectomy , Female , Germany , Humans , Hypertension, Pulmonary/mortality , Interdisciplinary Communication , Male , Middle Aged , Prognosis , Pulmonary Artery/surgery , Pulmonary Embolism/complications , Pulmonary Embolism/mortality , Referral and Consultation , Retrospective Studies , Survival Rate , ThrombectomyABSTRACT
BACKGROUND: Impairment of renal function is associated with adverse outcome in various diseases. Patients with pulmonary hypertension (PH) show diminished cardiac function and organ perfusion. The aim of this study was to investigate the associations between renal function and both haemodynamic parameters and long-term survival in patients with PH. METHODS: Blood was collected from 64 patients with PH (Dana Point class 1, 3 and 4) during right heart catheterization, and plasma was prepared. Creatinine, blood urea nitrogen (BUN), cystatin C, neutrophil-gelatinase-associated lipocalin (NGAL), fibroblast growth factor 23 (FGF-23) and α-Klotho levels were determined, and glomerular filtration rate (GFR) was estimated (eGFR). Parameters were evaluated using c-statistics and dichotomized for survival analysis based on receiver operating characteristic curves. RESULTS: The median follow-up time was 9.92 years with all-cause mortality as the primary end-point. Elevated BUN, cystatin C and creatinine levels were associated with decreased survival, with hazard ratios (HRs) of 3.237, 4.514 and 2.006, respectively, and equivalent performance according to c-statistics. Estimating GFR by CKD-EPI, MDRD and Cockcroft-Gault formulas resulted in HRs of 2.942, 2.694 and 3.306, respectively. Amongst these formulas, eGFR (Cockcroft-Gault) had the highest c-statistics of 0.674. There was a correlation between BUN and both cardiac index (τ = -0.39) and pulmonary vascular resistance index (τ = 0.249), whereas eGFR (CKD-EPI) was correlated with cardiac index (τ = 0.225). No correlations between either BUN or eGFR and right atrial pressure (RAP) were observed. NGAL, FGF-23 and α-Klotho had no prognostic impact or association with haemodynamic parameters. CONCLUSION: Comparison of markers of renal function for prognosis in PH demonstrated superiority of creatinine, cystatin C and BUN over NGAL, FGF-23 and α-Klotho. Minor decreases in eGFR influence long-term prognosis, and measurement of cystatin C levels might be useful to detect renal impairment in patients with a normal serum concentration of creatinine. Renal function in patients with PH is linked to cardiac index rather than RAP.
Subject(s)
Glomerular Filtration Rate , Hypertension, Pulmonary/blood , Hypertension, Pulmonary/mortality , Acute-Phase Proteins , Adult , Aged , Biomarkers/blood , Blood Urea Nitrogen , Creatinine/blood , Cystatin C/blood , Female , Fibroblast Growth Factor-23 , Fibroblast Growth Factors/blood , Follow-Up Studies , Glucuronidase/blood , Hemodynamics , Humans , Hypertension, Pulmonary/physiopathology , Klotho Proteins , Lipocalin-2 , Lipocalins/blood , Male , Middle Aged , Odds Ratio , Prognosis , Proto-Oncogene Proteins/bloodABSTRACT
The structural changes of a (111) oriented CeO2 film grown on a Si(111) substrate covered with a hex-Pr2O3(0001) interface layer due to post deposition annealing are investigated. X-ray photoelectron spectroscopy measurements revealing the near surface stoichiometry show that the film reduces continuously upon extended heat treatment. The film is not homogeneously reduced since several coexisting crystalline ceria phases are stabilized due to subsequent annealing at different temperatures as revealed by high resolution low energy electron diffraction and X-ray diffraction. The electron diffraction measurements show that after annealing at 660 °C the ι-phase (Ce7O12) is formed at the surface which exhibits a (â7 × â7)R19.1° structure. Furthermore, a (â27 × â27)R30° surface structure with a stoichiometry close to Ce2O3 is stabilized after annealing at 860 °C which cannot be attributed to any bulk phase of ceria stable at room temperature. In addition, it is shown that the fully reduced ceria (Ce2O3) film exhibits a bixbyite structure. Polycrystalline silicate (CeSi(x)O(y)) and crystalline silicide (CeSi1.67) are formed at 850 °C and detected at the surface after annealing above 900 °C.
ABSTRACT
The Mexican tetra, Astyanax mexicanus, comprises 29 populations of cave-adapted fish distributed across a vast karst region in northeastern Mexico. These populations have a complex evolutionary history, having descended from 'old' and 'young' ancestral surface-dwelling stocks that invaded the region â¼6.7 and â¼2.8 MYa, respectively. This study investigates a set of captive, pigmented Astyanax cavefish collected from the Micos cave locality in 1970, in which albinism appeared over the past two decades. We combined novel coloration analyses, coding sequence comparisons and mRNA expression level studies to investigate the origin of albinism in captive-bred Micos cavefish. We discovered that albino Micos cavefish harbor two copies of a loss-of-function ocular and cutaneous albinism type II (Oca2) allele previously identified in the geographically distant Pachón cave population. This result suggests that phylogenetically young Micos cavefish and phylogenetically old Pachón cave fish inherited this Oca2 allele from the ancestral surface-dwelling taxon. This likely resulted from the presence of the loss-of-function Oca2 haplotype in the 'young' ancestral surface-dwelling stock that colonized the Micos cave and also introgressed into the ancient Pachón cave population. The appearance of albinism in captive Micos cavefish, caused by the same loss-of-function allele present in Pachón cavefish, implies that geographically and phylogenetically distinct cave populations can evolve the same troglomorphic phenotype from standing genetic variation present in the ancestral taxon.
