TY - CHAP M1 - Book, Section TI - Gene Mutation A1 - Pyeritz, Reed E. A2 - Papadakis, Maxine A. A2 - McPhee, Stephen J. A2 - Rabow, Michael W. A2 - McQuaid, Kenneth R. PY - 2023 T2 - Current Medical Diagnosis & Treatment 2023 AB - Allelic heterozygosity most often results when different alleles are inherited from the egg and the sperm, but it also occurs as a consequence of spontaneous alteration in nucleotide sequence (mutation). Genetic change occurring during formation of an egg or a sperm is called a germinal mutation. When the change occurs after conception—from the earliest stages of embryogenesis to dividing cells in the body of the oldest adult—it is termed a somatic mutation. As is discussed below, the role of somatic mutation in the etiology of human disease is increasingly recognized. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1193140184 ER -