DNA is made up of monomers called nucleotides

DNA is made up of monomers called nucleotides. Nucleotides consist of a pentose sugar, a phosphate group, and a nitrogen base. Nucleotides are combined together to form tow long spiral strands to make a double helix .the double helical structure contains two complementary polynucleotide chains twisted, in which the bases are on the inside and the sugar-phosphate backbone on the outside, the two strands are known to be antiparallel(run in opposite directions) Mainly, there are 4 different types of nitrogen bases: Adenine(A), Thymine(T), Guanine(G), and Cytosine(C).the order of the bases in the DNA sequences form genes and it is how genetic information is stored which tell cells how to make proteins that carry out most of the activities within a cell.
A gene called ATP7B which is roughly 78 kilo bases long contains 21 exons and 20 introns with a cytogenic location: 13q14.3 provides instructions for making Copper-transporting ATPase protein. This protein is found in the liver, kidney, and brain and it transports copper from the liver to other organs; furthermore, copper-transport ATPase is essential for removing the excess copper from the body. More than 600 pathogenic variants in ATP7B have been recognized, with missense mutations being the most common. Mutations in the ATP7B gene cause Wilsons Disease, which is a rare autosomal recessive inherited disorder of copper metabolism. The condition is specialised by excessive deposition copper in different organs and tissues. In WD the liver does not exert the copper correctly and copper builds up and become toxic in the liver, brain, eyes and other organs. Overtime high levels of copper might lead to life-threatening organ damage. If WD is recognized in an early stage, damage to the affected organs could be minimized and lifelong neuropsychiatric, hepatic and systemic disabilities could be prevented. WD is analysed dependent on clinical indications and biochemical identification of copper metabolic disorder. Unfortunately, in early stages some patients could not be diagnosed because they do not exhibit the typical findings, and clinical manifestations vary notably among patients, thus genetic testing is believed to be the most efficient way to diagnose both symptomatic and presymptomatic patients.