FAT4 and Hennekam lymphangiectasia-lymphedema syndrome 2: Another protein-coding gene associated with Van Maldergem Syndrome 2 and Hennekam Lymphangiectasia–Lymphedema Syndrome 2 is the FAT4 gene (FAT Atypical Cadherin 4), which is involved in approximately 20% of Hennekam syndrome cases [6].