The most common cause of Angelman syndrome is a deletion of the maternal chromosome region 15q11-q13, which includes the UBE3A gene. Importantly, mutations and deletions of the UBE3A gene are sufficient to cause Angelman syndrome, making UBE3A the single gene responsible for the core symptoms of the disorder. Two major deletion classes known as class I and class II deletions in the 15q11-q13 region both cause Angelman syndrome.
1 ER+/PR+: About 65% of estrogen-receptor-positive breast cancers are also progesterone-receptor-positive. 2  This means that the cells have receptors for both hormones, which could be supporting the growth of the breast cancer.
Hormones, though, only bind to certain, compatible receptor types. Thyroid hormones and each steroid hormone group-the estrogens, androgens, progestins, glucocorticoids (stress hormones), and mineralocorticoids (water and ion-regulating hormones) - have a matching hormone receptor type. In this case, the estrogen hormone 17-beta-estradiol is the ligand, and the estrogen receptor is the protein. 2  Binding turns on, or activates, a hormone receptor. 3  Activation sets in motion cell signaling systems that trigger gene expression and lead to responses typical of a particular hormone.