47,XYY is not inherited; it usually occurs as a random event during the formation of sperm cells. An incident in chromosome separation during anaphase II (of meiosis II) called nondisjunction …

Dec 5, 2024 · 47,XYY syndrome (Jacobs syndrome) is a rare condition in which males have an additional Y chromosome in their genetic code.

Feb 4, 2025 · What is XYY syndrome? XYY syndrome, also known as Jacobs syndrome, is a chromosomal disorder characterized by the presence of an extra Y chromosome (47, XYY). …

Sep 10, 2024 · Jacobs syndrome, also known as 47,XYY syndrome, is a rare genetic condition that occurs in about 1 out of 1000 male children; this condition belongs to a group of …

Oct 3, 2012 · Search for detailed information on rare diseases, including NORD's authoritative Rare Disease Reports and data from other reliable sources. Interested in exploring the …

How do we know about XYY? If most boys and men with XYY are never diagnosed, how do we know about the impact of the extra Y chromosome?

Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically …

Feb 19, 2025 · XYY syndrome is a rare genetic condition that occurs in males, only when they are born with an additional Y chromosome in most or all of their cells. This means that instead of …

XYY Syndrome - Learn about the causes, symptoms, diagnosis & treatment from the Merck Manuals - Medical Consumer Version.

Apr 27, 2025 · Learn about the formation of YY chromosomes and what kinds of physical characteristics and symptoms are associated with XYY syndrome.