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Klinefelter Syndrome (Klinefelter's Syndrome)

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A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).

Also Known As:

Klinefelter's Syndrome; Syndrome, Klinefelter's; 48,XXYY Syndrome; 49,XXXXY Syndrome; Klinefelter Syndrome, Variants; XX Male Syndrome; XXXY Males; Klinefelter Syndromes; Klinefelter Syndromes, Variants; Klinefelters Syndrome; Syndrome, Klinefelter; Syndrome, Variants Klinefelter; Syndrome, XX Male; Syndromes, Klinefelter; Syndromes, Variants Klinefelter; Syndromes, XX Male; XX Male Syndromes; XXXY Male

Networked: 849 relevant articles (11 outcomes, 73 trials/studies)

Relationship Network

Disease Context: Research Results

Related Diseases

1.	Bipolar Disorder (Mania)
2.	Tremor (Tremors)
3.	Essential Tremor (Essential Tremors)
4.	Turner Syndrome (Turner's Syndrome)
5.	Hypogonadism (Hypergonadotropic Hypogonadism)

Experts

1.	van Rijn, Sophie: 10 articles (05/2015 - 06/2006)
2.	Bojesen, Anders: 9 articles (04/2015 - 07/2006)
3.	Ross, Judith L: 9 articles (01/2014 - 01/2005)
4.	Schlegel, Peter N: 9 articles (01/2014 - 02/2002)
5.	Tartaglia, Nicole: 9 articles (02/2013 - 01/2009)
6.	Swaab, Hanna: 8 articles (02/2014 - 06/2006)
7.	Gravholt, Claus H: 7 articles (10/2015 - 07/2006)
8.	Foresta, C: 7 articles (08/2015 - 01/2005)
9.	Ferlin, A: 7 articles (08/2015 - 01/2005)
10.	Gravholt, Claus Højbjerg: 6 articles (10/2015 - 01/2012)

Drugs and Biologics

Drugs and Important Biological Agents (IBA) related to Klinefelter Syndrome:

1.	Testosterone (Sustanon)FDA Link 11/01/1989 - "It is concluded that testosterone therapy is beneficial in all patients with Klinefelter's Syndrome." 11/01/2013 - "These findings suggest that testosterone replacement therapy may be effective in treating BMD deficiency in men with testosterone deficiency, especially those with Klinefelter syndrome." 10/01/2014 - "Re: Safety and efficacy of testosterone replacement therapy in adolescents with Klinefelter syndrome: A. " 05/01/2014 - "Safety and efficacy of testosterone replacement therapy in adolescents with Klinefelter syndrome." 09/01/1993 - "Early recognition of Klinefelter syndrome could be achieved by routinely measuring the size of the testes in school-boys aged 11 to 15 years and performing a karyotype in boys with a volume of less than 2 ml. Early psychological and educational support and testosterone replacement therapy initiated at onset of puberty may lead to improved social and academic outcomes."
2.	XXY syndromeIBA 08/01/2012 - "This finding may prove helpful in similar cases with symptoms of Klinefelter syndrome, but which exhibit an absence of the cell line 47,XXY in peripheral blood." 03/01/2011 - "In our study we found 12 patients (5%) with 47,XXY karyotype (Klinefelter syndrome), but these patients didn't have microdeletion of Y chromosomes. " 12/01/2010 - "Controlled studies should be done to determine the best age for TESE-ICSI in 47.XXY homogeneous Klinefelter syndrome patients." 01/01/2009 - "Klinefelter syndrome (47,XXY) was initially described in the context of its endocrinologic and physical features; however, subsequent studies have revealed specific impairments in verbal skills and social functioning. " 03/15/2008 - "The goal of this study was to expand the description of the cognitive development phenotype in boys with Klinefelter syndrome (47,XXY). "
3.	HormonesIBA 03/01/2013 - "Endocrinological data showed that their endocrine hormone levels were similar to that observed for Klinefelter syndrome, with higher FSH and LH levels and lower T levels. " 10/01/2012 - "Klinefelter syndrome subjects and controls evaluation included complete medical history, physical examination, measurement of concentrations of the reproductive hormones, lipidic and glycidic metabolism, AR function and sensitivity, ultrasound examinations (diameters, carotid intima-media thickness and brachial flow-mediated dilation) of brachial, common carotid and common femoral artery and abdominal aorta. " 06/01/2009 - "SLE developed in a preadolescent child with Klinefelter syndrome who had no detectable sex hormone." 07/01/2004 - "He was diagnosed as a case of 47XXY Klinefelter syndrome on the basis of hormone assay and karyotyping. " 10/01/2003 - "The coital activity in the group of men with Klinefelter's syndrome decreased after 35 years of age, before any decrease in serum male sex hormone levels occurred. "
4.	Estradiol (Estrace)FDA LinkGeneric 02/28/1997 - "The impact of oestradiol on ages at onset in schizophrenia reevaluated through Klinefelter syndrome." 03/01/1979 - "In five adult patients with Klinefelter's syndrome and two with Sertoli-cell-only syndrome, exogenous administration of 17 beta-oestradiol, resulting in a sustained and prolonged elevation of circulating oestrogen levels, had a biphasic effect on LH release. " 02/01/2007 - "Despite a median serum total and free testosterone and oestradiol levels being reduced (P < 0.001) and LH levels elevated (P < 0.001) in Klinefelter's syndrome and 46,XX-males, many subjects (69%) had total testosterone within the reference range. " 05/01/2002 - "It is possible that testosterone deficiency and increased levels of estradiol are primary responsible factors for this enhanced autoantibody production in Klinefelter's syndrome patients." 12/01/2004 - "Basal FSH, prolactin and estradiol levels were significantly higher whereas basal testosterone was significantly lower in patients with Klinefelter syndrome than in the control group. "
5.	Aromatase InhibitorsIBA 05/01/2014 - "Hormone supplementation with testosterone and aromatase inhibitors in adolescents with Klinefelter syndrome appears to be safe and effective for maintaining serum testosterone within the normal range. "
6.	Testolactone (Teslac)FDA Link 02/01/2002 - "Anastrazole appears to be at least as effective as testolactone for treating men with abnormal testosterone-to-estradiol ratios, except for the subset with the Klinefelter syndrome, who appeared to be more effectively treated with testolactone."
7.	Methylphenidate (Ritalin)FDA LinkGeneric 01/01/2014 - "Isolate attention difficulties in a boy with klinefelter syndrome effectively treated with methylphenidate."
8.	LithiumIBA 01/01/1997 - "We describe a manic patient with Klinefelter's syndrome who was treated successfully with lithium. "
9.	anastrozole (Arimidex)FDA LinkGeneric 02/01/2002 - "Anastrazole appears to be at least as effective as testolactone for treating men with abnormal testosterone-to-estradiol ratios, except for the subset with the Klinefelter syndrome, who appeared to be more effectively treated with testolactone."
10.	ChromatinIBA 07/01/1980 - "The study also showed a marked phenotypic overlap between the X-chromatin positive Klinefelter disease and the X-chromatin negative Klinefelter syndrome. " 09/01/1969 - "Biochemical studies in a patient with chromatin-negative Klinefelter's syndrome." 11/01/1963 - "CHROMATIN-POSITIVE KLINEFELTER'S SYNDROME: CLINICAL AND CYTOGENETIC STUDIES." 01/01/1960 - "[Familial studies on 20 patients with chromatin-positive Klinefelter's syndrome]." 12/01/1985 - "The causes of death in 466 X chromatin positive males (Klinefelter's syndrome) studied prospectively over the last 25 years have been analysed. "

Therapies and Procedures

1.	Deep Brain Stimulation 07/01/2000 - "Efficacy of unilateral deep brain stimulation of the thalamic ventralis intermedius nucleus in a patient with bipolar disorder associated with Klinefelter syndrome and essential tremor. "
2.	Drug Therapy (Chemotherapy) 01/01/2013 - "Because most men with NOA will have isolated regions of spermatogenesis within the testis, studies have illustrated that sperm can be retrieved in most men with NOA, including Klinefelter's syndrome (KS), prior history of chemotherapy and cryptorchidism. " 01/01/1994 - "A patient with bipolar disorder and previously undiagnosed Klinefelter's syndrome presented with acute mania refractory to pharmacotherapy and was successfully treated with electroconvulsive therapy. " 01/01/2010 - "The group included: i) children after cranial irradiation and chemotherapy due to medulloblastoma (3 patients), oligodenroglioma (1 patient), ependymoma (1 patient), optic chiasm glioma (2 patients), suprasellar germinal tumor (1 patient), ii) children with Hashimoto encephalopathy (2 patients), iii) children with Prader-Willi syndrome (20 patients), with Klinefelter syndrome (10 patients), with Albright syndrome (9 patients). " 01/01/2011 - "The purpose of this work is a presentation of cases of persons with Klinefelter Syndrome where, most probably--as a result of testosterone supplementation therapy, some aggressive behaviours occurred requiring implementation of pharmacotherapy and psychiatric hospitalisation. " 01/01/1985 - "Elevated serum gonadotropin levels direct further evaluation toward etiologies of gonadal failure, including gonadal dysgenesis, Klinefelter syndrome, and chemotherapy/irradiation damage. "
3.	Ligation 05/01/2005 - "However, the potential benefit of ligation of internal spermatic veins in patients with Klinefelter syndrome and a varicocele warrants further study. " 07/01/1992 - "Coronary-cameral fistula in association with Klinefelter syndrome: exercise-induced ventricular tachycardia late after surgical ligation."
4.	Renal Dialysis (Hemodialysis) 01/20/1991 - "In this study, the clinical significance of serum free testosterone levels was evaluated in a total of 248 subjects, including 120 healthy adult males (54 males aged 20-39, 26 males aged 40-59 and 41 males aged more than 60), 94 infertile males, 28 male hemodialysis patients, and 6 patients with Klinefelter's syndrome. "
5.	Aftercare (After-Treatment) 06/01/1989 - "Although the analysis of cell-cycle kinetics both after various culture times and after treatment with MMC revealed that there were no significant differences between the patient and normal control cells, patients with Klinefelter syndrome showed a tendency to cell-cycle delays after treatment with MMC in comparison with normal controls." 10/01/1997 - "We have therefore determined serum PSA levels before and 3 months after treatment in 13 patients with idiopathic hypogonadotropic hypogonadism (IHH) and 14 patients with Klinefelter's syndrome. " 09/01/1996 - "We, therefore, determined Lp(a), LpA-I, LpA-I:A-II, and other lipoprotein levels before and 3 months after treatment in 22 patients with idiopathic hypogonadotropic hypogonadism (IHH) and in 9 patients with Klinefelter's syndrome. " 05/27/1977 - "Hormone levels were measured in patients with Klinefelter's syndrome after treatment with 100 mg mesterolone cipionate (twice monthly). " 05/01/1998 - "Since little is known about the effects of gonadotropin and testosterone treatment on leptin levels in male hypogonadism, we determined fasting plasma leptin levels before and 3 months after treatment in 21 patients with idiopathic hypogonadotropic hypogonadism (IHH), 16 patients with Klinefelter's syndrome and 20 male controls. "