Quick Boards Review: Hepatolenticular Degeneration
Wilson’s Disease, also known as Hepatolenticular Degeneration, is a rare, autosomal recessive mutation in the ATP7B gene.1 This mutation causes a decrease in serum ceruloplasmin which is an important chaperone protein that aids in removing copper in the body.2 This is detrimental because when copper is not removed from the body, it can accumulate to toxic levels in areas such as the brain, liver, and eye.
kayser-Fleischer Ring
As primary eye care providers, it is important to recognize the ocular signs that may present with Wilson’s Disease. In the cornea, copper deposition can occur in Descemet’s layer and is known as a Kayser-Fleischer ring.2 Because this is a systemic disorder, you can expect to see a Kayser-Fleischer ring in both eyes, although they can be asymmetrical.
Lenticular Changes
Another important ocular structure to observe is the lens. The lens can also be susceptible to copper deposition and is known as a sunflower cataract.1 The sunflower cataract will appear as a greenish-brown opacity with spoke-like edges in the anterior capsule.1
A common misconception about Wilson’s disease is in the name “hepatolenticular” which refers to the sites where copper accumulates. As many people know, “hepato” refers to copper deposition in the liver which can cause a recurrent inflammation. The second half of the word, “lenticular,” interestingly enough, does not refer to the deposition of copper in the lens, but actually the lenticular nucleus in the brain.2
Within the basal ganglia in the brain, we have a lenticular nucleus that is divided into the putamen and globus pallidus. These two areas are important in regulating voluntary movement and cognition. When toxic amounts of copper accumulate in these two nuclei, extrapyramidal symptoms such as rigidity, tremor, and mental impairment can occur.2 An excellent parallel to this is Parkinson’s Disease. Similarly to Wilson’s Disease, the basal ganglia in Parkinson’s is impaired and the patient will present with motor and cognition issues.2
So, although the “lenticular” part of the name is a great way to remind ourselves of the copper deposition in the lens, it is important to understand that the word refers to the lenticular nucleus of the brain. This knowledge will help you better understand other major signs you can expect to see when a patient with Hepatolenticular Degeneration appears in your chair.
References
1. Lorincz MT. Neurologic Wilsons disease. Annals of the New York Academy of Sciences. 2009;1184(1):173-187. doi:10.1111/j.1749-6632.2009.05109.x.
2. Butterworth RF. Metal Toxicity, Liver Disease and Neurodegeneration. Neurotoxicity Research. 2010;18(1):100-105. doi:10.1007/s12640-010-9185-z.
