Lymphology Association of North America (LANA) Practice Exam

Which gene is associated with the genetic mutation leading to Milroy's Disease?

1. FOXC2

2. FLT2

3. FOXC4

4. FLT4

The correct answer is: FLT4

Milroy's disease is a hereditary condition characterized by congenital lymphedema, and it is specifically linked to mutations in the FLT4 gene. This gene encodes for a receptor known as vascular endothelial growth factor receptor 3 (VEGFR-3), which plays a critical role in lymphatic vessel development and function. Mutations in FLT4 disrupt normal lymphatic development, leading to the symptoms observed in Milroy's disease, which include swelling of the legs and feet due to lymphatic fluid accumulation. In contrast, the other genes listed do not have a direct association with Milroy's disease. FOXC2, for example, has been linked to other forms of lymphedema, such as lymphedema-distichiasis syndrome, but it is not responsible for Milroy's disease. Understanding the distinct roles of these genes helps to clarify why FLT4 is the correct answer when identifying the genetic basis specifically related to Milroy's disease.