Lymphedema refers to a group of disorders characterized by the accumulation of protein-rich fluid in the interstitial tissues, resulting from an imbalance between lymph production and it’s drainage via lymphatic vessels. More than 10 types of isolated primary LD is described, and among them CELSR1-associated lymphedema are one of the less studied. A family with two sibs, a 17-year-old boy and an 8-year-old girl, both diagnosed with primary LD, presented to the clinic. Both patients were observed with primary symptoms of LD at 2-3 months of age, presented by the swelling of right foot. Lymphatic pathologies were not diagnosed in parents or close relatives. The rare c.7664A>C variant, resulting in the H2555P missense mutation in the intracellular loop of CELSR1 transmembrane domain, was discovered in a patients. The clinical signs, MRL scanning data, in silico predictors and the absence of known pathogenic mutations or rare variants of unknown significance in other genes, associated with the development of primary lymphedema, allow us to assume that c.7664A>C variant of CELSR1 may be responsible for pathogenesis of the disease in the presented family case.