In Klinefelter syndrome, there are two X chromosomes and a Y chromosome (XXY). In rare cases, additional X chromosomes (XXXY or XXXXY) may also be linked to Klinefelter syndrome. The condition is confirmed genetically by the demonstration of one or more extra X chromosomes.

Klinefelter syndrome (KS), also known as 47,XXY, is a chromosome anomaly where a male has an extra X chromosome. [10] . These complications commonly include infertility and small, poorly functioning testicles (if present). These symptoms are often noticed only at puberty, although this is one of the most common chromosomal disorders.

由于克氏综合征患者（47，XXY）比正常的男性（46，XY）多了一条X染色体，是一种先天性疾病，曾经被大多数医生认为没有治疗价值，不可能获得自己的亲生孩子，然而，随着显微取精手术的出现，这种观点发生了翻天覆地的改变。

2021年12月7日 · This case series expands our knowledge of the prenatal presentation of 47, XXY by identifying first and second trimester fetal sonographic abnormalities. Prenatal identification of this condition enables accurate counseling, focused prenatal management, and early postnatal interventions to ameliorate some of the known complications.

This case series expands our knowledge of the prenatal presentation of 47, XXY by identifying first and second trimester fetal sonographic abnormalities. Prenatal identification of this condition enables accurate counseling, focused prenatal management, and early postnatal interventions to …

Klinefelter syndrome (KS), or 47, XXY, is the most commonly occurring sex chromosome aneuploidy, with an estimated incidence of approximately 1 in 660 live male births. 1 KS can present in childhood with developmental delay, learning disability, and behavioral disturbances, and in adulthood with infertility and osteoporosis. 1, 2 Studies have ...

Klinefelter syndrome is a chromosomal disorder present in 1 out of 400 to 1,000 male newborns in Western populations. Two-thirds of affected newborns show a karyotype of 47,XXY. Few studies have examined the incidence of Klinefelter syndrome in ...

Among the 19 cases of confirmed fetal XXY, 14 elected pregnancy termination, and the rest five led to live birth. Four of the five babies (1 month, 5 months, 1 year, 1.5 years old, respectively) did not show clinical symptoms by now, but the eldest one, who was 2 years old at then, showed developmental delay, mental retardation, severe autism ...

2023年9月1日 · Assisted reproductive technology, especially micro-testicular sperm extraction, has an important role, especially for those with 47,XXY; however, more recent data show promising techniques for the in vitro maturation of spermatogonial stem cells …

Klinefelter syndrome (47, XXY karyotype) is the spectrum of phenotypic features resulting from a sex chromosome complement that includes two or more X chromosomes and one Y chromosome (Figure 135-1).