duete; see due, ty 2 ]. syn: duty, obligation refer to something a person feels bound to do. A duty often applies to what a person performs in fulfillment of the permanent dictates of conscience, piety, right, or law: one's duty to tell the truth; a parent's duty to raise children properly.
Mutations in the RB1 gene are responsible for most cases of retinoblastoma. RB1 is a tumor suppressor gene, which means that it normally regulates cell growth and keeps cells from dividing too rapidly or in an uncontrolled way.
Retinoblastoma, a neuroblastic tumor, is the most common primary intraocular malignancy of childhood. Patients usually present with leukokoria (white reflex or white pupil), detected in primary care. The mean age at diagnosis is 12 months for bilateral tumors and 24 months for unilateral tumors.etinoblastoma is a neuroblastic tumor that usually is detected in primary care. It is the most common primary intraocular malignancy of childhood, with an incidence of approximately one in 20,000, and affects males and females equally.