A novel mutation in the conserved sequence of vascular endothelial growth factor receptor 3 leads to primary lymphoedema

OBJECTIVE: To investigate whether lymphoedema in a Chinese family showed the hereditary and clinical characteristics of Milroy disease, an autosomal dominant form of congenital lymphoedema, typically characterized by chronic lower limb tissue swelling due to abnormal lymphatic vasculature development, and to perform mutational analyses of vascular endothelial growth factor receptor (VEGFR)3. METHODS: Individuals from a three-generation family affected by congenital lymphoedema were clinically assessed for Milroy disease. Mutation analysis of VEGFR3 was performed using DNA from family members and healthy controls. RESULTS: Out of 20 family members, eight were diagnosed with hereditary lymphoedema. Mutation analyses revealed a novel mutation site for c.3163 G>A, resulting in a p.1055D>N mutation in the second tyrosine kinase domain of VEGFR3, which was present in affected individuals only (absent in all unaffected family members and 130 healthy controls). Computed functional analyses showed the mutation may lead to structural alterations with a probability of 0.99999 of being disease causing. CONCLUSION: A novel mutation associated with Milroy disease was identified in a Chinese family, expanding our knowledge of VEGFR3 gene function and providing a potential molecular target for treating hereditary lymphoedema.