Inability to develop or maintain an erection of the penis.

The presence of chronic increased pressure in the systemic arterial system.

An episodic vasoconstriction resulting in discoloration of the skin and pain in the affected areas, often involving fingers or toes. Classically associated with triphasic color changes (white, blue, red) but may be biphasic. Often occurs in response to cold temperatures or emotional stress. May be primary or secondary to an underlying autoimmune disease.

A noninflammatory, progressive occlusion of the intracranial carotid arteries owing to the formation of netlike collateral arteries arising from the circle of Willis.

Difficulty in swallowing.

A disorder of esophageal motility characterized by the inability of the lower esophageal sphincter to relax during swallowing and by inadequate or lacking peristalsis in the lower half of the body of the esophagus.

Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength.

A generalized-onset seizure is a type of seizure originating at some point within, and rapidly engaging, bilaterally distributed networks. The networks may include cortical and subcortical structures but not necessarily the entire cortex.

A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. It is said to be the third leading cause of death in the United States. Gunel and Lifton (1996) noted that about 20% of strokes are hemorrhagic, resulting in bleeding into the brain. Ischemic strokes, resulting from vascular occlusion, account for the majority of strokes. Bersano et al. (2008) reviewed genetic polymorphisms that have been implicated in the development of stroke. Candidate genes include those involved in hemostasis (see, e.g., F5; 612309), the renin-angiotensin-aldosterone system (see, e.g., ACE; 106180), homocysteine (see, e.g., MTHFR; 607093), and lipoprotein metabolism (see, e.g., APOE; 107741). See also hemorrhagic stroke, or intracerebral hemorrhage (ICH; 614519).

A reduction in the number of circulating thrombocytes.

Livedo reticularis is characterized by the presence of a bluish purple, mottled or netlike pattern in unbroken circles on the skin. Exposure to cold environments usually intensifies the vascular pattern. Presumably, the condition results from slow or stagnant blood flow, vessel-wall pathology, and decreased oxygen tension.

A reticular discoloration of the skin with cyanotic (reddish-blue appearing) areas surrounding pale central areas due to dilation of capillary blood vessels and stagnation of blood within the vessels. Cutis marmorata generally occurs on the legs, arms and trunk and is often more severe in cold weather.