<prompt> A 14-year-old boy with difficulty in walking and behavioural disturbance, recovered from prolonged jaundice recently, has bluish pigmentation over lunula. The next investigation to be done:Nail fold capillaroscopySlit lamp examinationBiopsy of the pigmented areaAnkle-Brachial Pressure Index  <response>: Ans: b Slit lamp examinationRef: Harrisons Principles of Internal Medicine, 19th edition, Page 2519; Nail Abnormalities: Clues to Systemic Disease Am Fam Physician 2004;69: 1417-24WILSONS DISEASEAutosomal recessive disorder caused by mutations in ATP7B gene, a membrane bound copper transporting ATPase on chromosome 13Primarily involves liver, brain, kidney and corneaAlso known as hepatolenticular degenerationClinical FeaturesHepatic: Commonly manifest in children of 5 to 6 years of age hepatitis, cirrhosis, hepatic decompensation, associated with hemolytic anemia, hemolysis and liver disease suspect Wilsons diseaseNeurologic: Occurs in early twenties; Dystonia mainly of face, incoordination, tremor, autonomic disturbances, abnormal eye movements, no sensory abnormalities and muscular weaknessPsychiatric: Loss of emotional attachment, depression, hyperactivity, schizophreniaOcular: Sunflower cataracts, Kayser-Fleischer ring in the descemets membraneRenal: Microscopic hematuria, proximal tubular defects like Fanconis syndromeInvestigations:Serum ceruloplasmin - lowSerum copper level - total decreased free copper increase24 hours urine cu excretion - 1.6 micromolKF rings slit lamp exam - 99 in neurological and psychiatric symptoms 30-50 in hepatic presentationLiver biopsy - 250mgg of dry tissue gold standard for diagnosisMRI brain - shows damage in basal gangliaNail Findings and Associated Systemic ConditionsNail findingAssociated systemic conditionsShape or growth change ClubbingInflammatory bowel disease, pulmonary malignancy, asbestosis, chronic bronchitis, COPD, cirrhosis, congenital heart disease, endocarditis, atrioventricular malformations, fistulasKoilonychiaIron deficiency anemia, hemochromatosis, Raynauds disease, SLE, trauma, nail-patella syndromeOnycholysisPsoriasis, infection, hyperthyroidism, sarcoidosis, trauma, amyloidosis, connective tissue disordersPittingPsoriasis, Reiters syndrome, incontinentia pigmenti, alopecia areataBeaus linesAny severe systemic illness that disrupts nail growth, Raynauds disease, pemphigus, traumaYellow nailLymphedema, pleural effusion, immunodeficiency, bronchiectasis, sinusitis, rheumatoid arthritis, nephrotic syndrome, thyroiditis, tuberculosis, Raynauds diseaseColor change Terrys white nailsHepatic failure, cirrhosis, diabetes mellitus, CHF, hyperthyroidism, malnutritionAzure lunulaHepatolenticular degeneration Wilsons disease, silver poisoning, quinacrine therapyHalf-and-half nailsSpecific for renal failureMuehrckes linesSpecific for hypoalbuminemiaMees linesArsenic poisoning, Hodgkins disease, CHF, leprosy, malaria, chemotherapy, carbon monoxide poisoning, other systemic insultsDark longitudinal streaksMelanoma, benign nevus, chemical staining, normal variant in darkly pigmented peopleLongitudinal striationsAlopecia areata, vitiligo, atopic dermatitis, psoriasisSplinter hemorrhageSubacute bacterial endocarditis, SLE, RA, antiphospholipid syndrome, malignancies, oral contraceptive use, pregnancy, psoriasis, traumaTelangiectasiaRheumatoid arthritis, SLE, dermatomyositis, scleroderma 