Klinefelter syndrome - Wikipedia
Those with XXY are more likely than others to have certain health problems, such as autoimmune disorders, breast cancer, venous thromboembolic disease, and osteoporosis.
Klinefelter syndrome - Symptoms and causes - Mayo Clinic
Oct 29, 2024 · Klinefelter syndrome is a genetic condition that occurs before birth, but it often isn't diagnosed until adulthood. Klinefelter syndrome may affect testicular growth. This results in smaller …
Klinefelter syndrome: MedlinePlus Genetics
Klinefelter syndrome, also called 47,XXY, is a chromosomal condition that affects male development. The signs and symptoms of Klinefelter syndrome vary. In some cases, the features are so mild that …
XXY Syndrome: What It Is, Causes, Signs and Symptoms ...
Mar 4, 2025 · What is XXY syndrome? XXY syndrome, also known as Klinefelter syndrome (KS), is a genetic condition characterized by the presence of an extra X chromosome (47, XXY). Humans have …
Klinefelter Syndrome (XXY Syndrome) - WebMD
Oct 28, 2024 · Klinefelter syndrome, also known as XXY syndrome, is a condition in boys and men that’s caused by an extra X chromosome. It can affect physical and mental development.
Klinefelter Syndrome or XXY Syndrome - Symptoms and Diagnosis
Dec 18, 2025 · A male fetus typically ends up having an XXY chromosome due to either the ova or the sperm containing an extra X chromosome. Statistically more probability of XXY syndrome is …
Klinefelter Syndrome - Johns Hopkins Medicine
Most men are born with a pair of XY chromosomes, while most females are born with pair of XX chromosomes. Klinefelter syndrome occurs when a male is born with an extra X chromosome. Thus …
Klinefelter Syndrome: What It Is, Symptoms & Treatment
Oct 9, 2023 · What is Klinefelter syndrome? Klinefelter syndrome is a genetic disorder in which males have an additional X chromosome in their genetic code. Most males have 46 chromosomes …
Klinefelter syndrome - NHS
Feb 20, 2025 · Klinefelter syndrome (sometimes called Klinefelter's, KS or XXY) is where boys and men are born with an extra X chromosome. Chromosomes are packages of genes found in every cell in …
Frequently Asked Questions - The Association for X and Y ...
Rather than the usual pattern of 46 chromosomes, with one X chromosome and one Y chromosome, there is an additional X chromosome, resulting in a genetic signature of 47,XXY.