XXYY syndrome is a sex chromosome anomaly in which males have two extra chromosomes, one X and one Y chromosome. Human cells usually contain two sex chromosomes, one from the mother and one from the father. Usually, females have two X chromosomes (XX) and males have one X and one Y chromosome (XY).

XXYY Syndrome is the name attached to the cluster of symptoms that arise as a result of the 48,XXYY chromosome pattern. 48,XXYY is one of several types of sex chromosome variations, including those that are considered as variants of Klinefelter Syndrome, 47,XXY and XXXY, XXXXY, XY/XXY and another syndrome called XYY, all of which affect males.

48,XXYY syndrome is a condition related to the the sex chromosomes. People normally have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will …

That means the genetic signature for a person with 46 chromosomes is either 46,XY (males), or 46,XX (females). Any variation from these typical numbers is referred to scientifically as an “aneuploidy.” If there is one additional X or Y, it is known as a “trisomy” (“tri” denoting the number 3). Genetic conditions that reflect a trisomy include:

XXYY syndrome is the result of having extra copies of both the X and Y chromosomes, occurring when a normal female oozyte (Xm) is fertilized with an aneuploidy sperm (X p Y p Y p) produced from double nondisjunction during meiosis.

Sex chromosomes are chromosomes, or packages of DNA, that are found inside the nucleus of all of your cells. There are two different kinds: X and Y, which determine whether you’re...

1998年10月3日 · Chromosome analysis showed 47, XXY karyotype in all 100 metaphases analysed. Hormone profiles showed average female range of corticotrophin, T3, T4, thyrotrophin, and testosterone. Progesterone and prolactin were higher when compared with normal female levels. Histology of the right gonad showed features compatible with ovarian stroma.

2025年1月7日 · 48 XXYY 核型人通常表现为男性，估计每 18000 到 40000 名男性新生儿中有 1 人核型如此。 1960 年，Sylfest Muldal 与 Charles H. Ockey 描述了一名 48 XXYY 核型的 15 岁智障男孩 。那之后数十年间，有更多相关研究，例如：

XXYY syndrome occurs in approximately 1:18,000–1:40,000 males. Although the physical phenotype is similar to 47,XXY (tall stature, hypergonadotropic hypogonadism, and infertility), XXYY is associated with additional medical problems and more significant neurodevelopmental and psychological features.

48,XXYY is a rare condition typically due to a sporadic aneuploidy event with an estimated recurrence risk of <1% (may be higher for cases of advanced maternal age). Genetic counseling for this condition should include a review of the possible and highly variable physical, medical, developmental and psychological features of 48,XXYY.