This panel consists of 21 genes that have been associated with circulatory and lymphatic vascular disorders including telangiectasia, lymphedema, and capillary malformations. The presentation of these disorders can be extremely variable. Inheritance is most often autosomal dominant with incomplete penetrance, but some forms of these conditions appear to follow an autosomal recessive pattern. The hereditary hemorrhagic telangiectasia syndromes may include nosebleeds, gastrointestinal bleeds, and potentially life-threatening brain, liver, or lung hemorrhages. Seizures and headaches may also occur although some individuals remain asymptomatic. Lymphedema syndromes show great variability and may improve or worsen with age, be unilateral or bilateral, and may include additional features of cellulitis, hydrocele, and skin or nail changes. Eye abnormalities, hearing loss, and developmental delays may occur in some of these disorders.