Lymphatic malformation-9 (LMPHM9) is an autosomal dominant disorder characterized by the onset of lower-extremity lymphedema in the first decades of life. Imaging may show lymph backflow and defects in lymph channel valves. There is variable expressivity and incomplete penetrance; female mutation carriers are more likely to show disease manifestations than male carriers (summary by Erickson et al., 2019).
For a discussion of genetic heterogeneity of lymphatic malformation, see 153100. [from
OMIM]