The word allele is a short form of allelomorph (other form, a word coined by William Bateson and Edith Rebecca Saunders), which was used in the early days of genetics to describe variant forms of a gene detected as different phenotypes.
Causes. Male sexual arousal is a complex process that involves the brain, hormones, emotions, nerves, muscles and blood vessels. Erectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction.Sometimes a combination of physical and psychological issues causes erectile dysfunction.For instance, a minor physical condition that slows your sexual response might cause anxiety about maintaining an erection.rectile dysfunction can result from a problem with any of these. Likewise, stress and mental health concerns can cause or worsen erectile dysfunction. Sometimes a combination of physical and psychological issues causes erectile dysfunction.
1 There are two root causes of erectile dysfunction (ED): psychological and medical. High blood pressure is a contributing medical factor that leads to ED. HBP damages the entire vascular system.  Adequate blood flow is necessary for erection.