Klinefelter syndrome is the most common chromosome abnormality in humans. The estimated prevalence is one in 500 to one in 1000 males but due to the widely variable and often aspecific features, only one in four cases are recognized. The most specific clinical features which can be observed at adult age are small testes, gynecomastia, female distribution of fat and body hair, slightly increased body length due to an increased leg length and azoospermia. Cognition is characterized by verbal deficits and psychosocial features include autistiform behavior. Structural brain abnormalities have been observed by MRI, such as decreased brain volumes and a decrease of asymmetry in areas corresponding to language performance. In the vast majority of cases a non-mosaic 47,XXY karyotype is observed. Parental imprinting of the extra X chromosome, variable inactivation of some X-chromosomal genes and CAG repeat length polymorphism of the androgen receptor may all be related to the variability of the phenotype. Surgical procedures of obtaining sperm in combination with repeated intracytoplasmic sperm injection/in vitro fertilization treatment may allow up to one in four men with Klinefelter syndrome to father children.
Mediastinal germ cell tumour associated with Klinefelter syndrome. A report of case and review of the literature
Fertility in a 47,XXY patient: assessment of biological paternity by deoxyribonucleic acid fingerprinting
Klinefelter's syndrome in Sardinia and Scotland. Comparative studies of parental age and other aetiological factors in 47,XXY
47,XXY (Klinefelter syndrome) and 47,XYY: estimated rates of and indication for postnatal diagnosis with implications for prenatal counselling
Delivery of normal twins following the intracytoplasmic injection of spermatozoa from a patient with 47,XXY Klinefelter's syndrome
Volumetric magnetic resonance imaging study of the brain in subjects with sex chromosome aneuploidies
Meiotic aneuploidy in the XXY mouse: evidence that a compromised testicular environment increases the incidence of meiotic errors
Effect of the androgen receptor CAG repeat polymorphism on transcriptional activity: specificity in prostate and non-prostate cell lines
Meiotic behaviour of the sex chromosomes in three patients with sex chromosome anomalies (47,XXY, mosaic 46,XY/47,XXY and 47,XYY) assessed by fluorescence in-situ hybridization
Testicular ultrasonography and extended chromosome analysis in men with nonmosaic Klinefelter syndrome: a prospective study of possible predictive factors for successful sperm recovery
Sperm aneuploidy in fathers of children with paternally and maternally inherited Klinefelter syndrome
Functional neuroimaging provides evidence of anomalous cerebral laterality in adults with Klinefelter's syndrome
Klinefelter syndrome in adolescence: onset of puberty is associated with accelerated germ cell depletion
Colobomas of the iris and choroid and high signal intensity cerebral foci on T2-weighted magnetic resonance images in Klinefelter's syndrome.
X-chromosome inactivation patterns and androgen receptor functionality influence phenotype and social characteristics as well as pharmacogenetics of testosterone therapy in Klinefelter patients
A man with Klinefelter's syndrome and new abdominal distension: a discussion of evaluation and management.
Aberrant gene expression profiles in pluripotent stem cells induced from fibroblasts of a Klinefelter syndrome patient.
Can attention deficits predict a genotype? Isolate attention difficulties in a boy with klinefelter syndrome effectively treated with methylphenidate
White matter microstructure in a genetically defined group at increased risk of autism symptoms, and a comparison with idiopathic autism: an exploratory study
Neural systems for social cognition: gray matter volume abnormalities in boys at high genetic risk of autism symptoms, and a comparison with idiopathic autism spectrum disorder
In search of an efficient injection technique for future clinical application of spermatogonial stem cell transplantation: infusion of contrast dyes in isolated cadaveric human testes
No influence of parental origin of intact X chromosome and/or Y chromosome sequences on three-year height response to growth hormone therapy in Turner syndrome
Perspectives in Pediatric Pathology, Chapter 16. Klinefelter Syndrome and Other Anomalies in X and Y Chromosomes. Clinical and Pathological Entities
The effect of early life stress on the cognitive phenotype of children with an extra X chromosome (47,XXY/47,XXX)
A review of neurocognitive functioning of children with sex chromosome trisomies: Identifying targets for early intervention
A child with Klinefelter syndrome and both IgE-mediated food allergy and low proportion of naive Treg
Early developmental impact of sex chromosome trisomies on attention deficit-hyperactivity disorder symptomology in young children.
Effect of sex chromosome number variation on attention-deficit/hyperactivity disorder symptoms, executive function, and processing speed.
Autoimmune diseases occur as a result of an attack by the immune system on the body’s own tissues resulting in damage and dysfunction. There are different types of autoimmune diseases, in which there is a complex and unknown interaction between genetics and the environment. Discover the latest research on autoimmune diseases here.