Systemic lupus erythematosus (SLE) disproportionately affects females. Recent work demonstrates that men with Klinefelter's syndrome (47,XXY males) have a similar risk of developing SLE as do genotypic females. We present an unusual case of an African American family with two SLE affected individuals in which one of the SLE patients also has Turner's syndrome [46,X,del(X)(q13)]. While not definitive, this family raises interesting questions regarding the role of genes located on the X chromosome in the development of SLE. The paucity of case reports documenting the overlap of SLE with Turner's syndrome while there is and association of male SLE with Klinefelter's syndrome suggests a lower risk of SLE in Turner's females. These observations are consistent with a gene dose effect at X with two X chromosomes (46,XX or 47,XXY) conferring higher risk and one X chromosome (46,XY or 45,XO) conferring lower risk of SLE.
About 90% of patients with systemic lupus erythematosus (SLE) are female. We hypothesize that the number of X chromosomes, not sex, is a determinate of risk of SLE. Number of X chromosomes was determined by single nucleotide typing and then confirmed by karyotype or fluorescent in situ hybridization in a large group of men with SLE. Presence of an sry gene was assessed by rtPCR. We calculated 96% confidence intervals using the Adjusted Wald method, and used Bayes’ theorem to estimate the prevalence of SLE among 47,XXY and 46,XX men. Among 316 men with SLE, 7 had 47,XXY and 1 had 46,XX. The rate of Klinefelter’s syndrome (47,XXY) was statistically different from that found in control men and from the known prevalence in the population. The 46,XX man had an sry gene, which encodes the testes determining factor, on an X chromosome as a result of an abnormal crossover during meiosis. In the case of 46,XX, 1 of 316 was statistically different from the known population prevalence of 1 in 20,000 live male births. A previously reported 46,XX man with SLE had a different molecular mechanism in which there were no common gene copy number abnormalities with our patient. Thus, men with SLE are enriched for conditions with additional X chromosomes. Especially since 46,XX men are generally normal males, except for infertility, these data suggest the number of X chromosomes, not phenotypic sex, is responsible for the sex bias of SLE.
Systemic lupus erythematosus; Klinefelter’s syndrome; male 46; XX; female bias; X chromosome
Similar to other autoimmune diseases, systemic lupus erythematosus (SLE) predominately affects women. Recent reports demonstrate excess Klinefelter’s among men with SLE and a possible under-representation of Turner’s syndrome among women with SLE as well as a case report of a 46,XX boy with SLE. These data suggest that risk of SLE is related to a gene dose effect for the X chromosome. Such an effect could be mediated by abnormal inactivation of genes on the X chromosome as has been demonstrated for CD40L, or by genetic polymorphism as has been demonstrated for Xq28. On the other hand, a gene dose effect could also be mediated by a gene without an SLE-associated polymorphism in that a gene that avoids X inactivation will have a higher level of expression in persons with two X chromosomes.
Systemic lupus erythematosus; Genetics; X chromosome
Systemic lupus erythematosus (SLE) is more common among women than men with a ratio of about 10 to 1. We undertook this study to describe familial male SLE within a large cohort of familial SLE. SLE families (two or more patients) were obtained from the Lupus Multiplex Registry and Repository. Genomic DNA and blood samples were obtained using standard methods. Autoantibodies were determined by multiple methods. Medical records were abstracted for SLE clinical data. Fluorescent in situ hybridization (FISH) was performed with X and Y centromere specific probes, and a probe specific for the toll-like receptor 7 gene on the X chromosome. Among 523 SLE families, we found five families in which all the SLE patients were male. FISH found no yaa gene equivalent in these families. SLE-unaffected primary female relatives from the five families with only-male SLE patients had a statistically increased rate of positive ANA compared to SLE-unaffected female relatives in other families. White men with SLE were 5 times more likely to have an offspring with SLE than were White women with SLE but there was no difference in this likelihood among Black men. These data suggest genetic susceptibility factors that act only in men.
Systemic lupus erythematosus; men; autoantibodies; genetics
The association of achondroplasia and Klinefelter syndrome is extremely rare. To date, five cases have been previously reported, all of them diagnosed beyond the postnatal period, and only one was molecularly characterized. We describe the first case of this unusual association diagnosed in the neonatal period, the clinical findings and the molecular studies undertaken.
The boy was born at term with clinical and radiological features indicating the diagnosis of achondroplasia or hypochondroplasia combined with the prenatal karyotype of Klinefelter syndrome (47,XXY). Neonatal FGFR3 mutation screening showed that the newborn was heterozygous for the classic achondroplasia G340R mutation. Microsatellite marker analysis showed that the sex chromosome aneuploidy had arisen from a non-disjunction error in paternal meiosis I, with a recombination event in the pseudoautosomal region 1 (PAR1).
Specific mutation analysis is appropriate to confirm the clinical diagnosis of achondroplasia for appropriate diagnosis, prognosis, and genetic counseling, especially when the karyotype does not explain the abnormal prenatal sonographic findings. In the present case, a recombination event was observed in the PAR1 region, although recombinational events in paternally derived Klinefelter syndrome cases are much rarer than expected.
Klinefelter syndrome; Achondroplasia; Mutation; Karyotype; Prenatal diagnosis
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 Korea. The aim of this study was to investigate the incidence of Klinefelter syndrome by use of prenatal screening tests.
Materials and Methods
From January 2001 to December 2010, 18,049 pregnant women who had undergone a chromosomal study for fetal anomalies were included. For fetuses that were diagnosed as having Klinefelter syndrome, the patients' medical records were retrospectively reviewed. Both parents' ages, the reason for the chromosomal studies, and karyotypes were investigated.
We found that 22 of 18,049 (0.12%) fetuses were diagnosed with Klinefelter syndrome. The incidence of this disorder in male fetuses was 22 of 9,387 (0.23%). Also, 19 of the newborns (86.4%) showed a karyotype of 47,XXY; the other newborns showed karyotypes of 48,XXY,+21; 48,XXY,+12/46,XY; and 47,XXY/45,X/46,XY. The mean age of the mothers was 36.1 years, and 2 women had a past history of a Down syndrome pregnancy. Nine mothers had a normal spontaneous delivery, 9 mothers underwent artificial abortion, and 2 fetuses were spontaneously aborted.
The incidence of Klinefelter syndrome as reported in this study is higher than in previous studies. Further studies with a broader population should be considered to confirm these results.
Karyotype; Klinefelter syndrome; Male infertility
Klinefelter's syndrome is a sex chromosome abnormality with low androgen level. The varied manifestations of the mental symptoms in some of them, that are inexplicable based on their genotype alone, has fascinated the researchers. We present here a case of Klinefelter's syndrome having a karyotype of mos 47, XXY, and also inversion in 9th chromosome, with schizophrenia. Despite the view that inv 9 is a normal variant, it is still worthwhile to explore whether it has any role in the etiology of schizophrenia especially when it occurs with other genotypic aberrations that are suspected to have relevance to psychiatric disorders including the Klinefelter's syndrome.
Chromosomes; genetics; psychosis; schizophrenia
Klinefelter syndrome is the most common chromosomal aneuploidy in men (XXY karyotype, 1 in 600 live births) and results in testicular (infertility and androgen deficiency) and nontesticular (cognitive impairment and osteoporosis) deficits. The extent to which skeletal changes are due to testosterone deficiency or arise directly from gene overdosage cannot be determined easily in humans. To answer this, we generated XXY mice through a four-generation breeding scheme. Eight intact XXY and 9 XY littermate controls and 8 castrated XXY mice and 8 castrated XY littermate controls were euthanized at 1 year of age. Castration occurred 6 months prior to killing. A third group of 9 XXY and 11 XY littermates were castrated and simultaneously implanted with a 1-cm Silastic testosterone capsule 8 weeks prior to sacrifice. Tibias were harvested from all three groups and examined by micro–computed tomography and histomorphometry. Blood testosterone concentration was assayed by radioimmunoassay. Compared with intact XY controls, intact androgen-deficient XXY mice had lower bone volume (6.8% ± 1.2% versus8.8% ± 1.7%, mean ± SD, p = .01) and thinner trabeculae (50 ± 4 µm versus 57 ± 5 µm, p = .007). Trabecular separation (270 ± 20 µm versus 270 ± 20 µm) or osteoclast number relative to bone surface (2.4 ± 1.0/mm2 versus 2.7 ± 1.5/mm2) did not differ significantly. Testosterone-replaced XXY mice continued to show lower bone volume (5.5% ± 2.4% versus 8.1% ± 3.5%, p = .026). They also exhibited greater trabecular separation (380 ± 69 µm versus 324 ± 62 µm, p = .040) but equivalent blood testosterone concentrations (6.3 ± 1.8 ng/mL versus 8.2 ± 4.2 ng/mL, p = .28) compared with testosterone-replaced XY littermates. In contrast, castration alone drastically decreased bone volume (p < .001), trabecular thickness (p = .05), and trabecular separation (p < .01) to such a great extent that differences between XXY and XY mice were undetectable. In conclusion, XXY mice replicate many features of human Klinefelter syndrome and therefore are a useful model for studying bone. Testosterone deficiency does not explain the bone phenotype because testosterone-replaced XXY mice show reduced bone volume despite similar blood testosterone levels. © 2010 American Society for Bone and Mineral Research.
aneuploidy; klinefelter syndrome; XXY; testosterone; bone; x-inactivation; osteoporosis
A 39 year old male with primary infertility was diagnosed as having Klinefelter syndrome by conventional cytogenetic analysis, which also showed an abnormal chromosome 12. Fluorescence in situ hybridisation (FISH) analysis of the aberrant chromosome using a 12 specific centromeric probe showed a break in the alphoid repeats followed by an inversion within the short arm, resulting in a pseudodicentric chromosome. Further FISH analyses using telomeric and subtelomeric probes showed that the other breakpoint was in the subtelomeric region of the short arm. The karyotype is designated 47,XXY,inv(12)(p10p13.3). To our knowledge this is the first report of a case of "centric inversion".
We present the case of a young man with type II diabetes, stage III chronic kidney disease, hypertension, obstructive sleep apnea and diabetes who presented to the Georgetown University Hospital Center for Wound Healing with refractory lower extremity ulcers. Autoimmune work-up was negative. However, chromosome analysis showed a genetic variant of Klinefelter’s syndrome (48 XXYY). Lower extremity ulceration is a recognised complication of Klinefelter’s syndrome. The pathogenesis of ulcers in this endocrinopathy is unclear, but associations with abnormalities of fibrinolysis and prothrombotic states are reported. This case emphasises the importance of considering Klinefelter’s syndrome in the differential diagnosis of a sterile male patient with non healing lower extremity ulcers.
Fibrinolysis; Klinefelter’s syndrome; Leg ulcer; Prothrombotic
Two cases of benign neurogenic amyotrophy associated with Klinefelter's syndrome are reported. Both presented with slowly progressive, diffuse neurogenic muscle atrophy of juvenile onset. Both had a karyotype of XXY. Amplification, by the polymerase chain reaction, of a fragment of androgen receptor that was related to bulbospinal muscular atrophy, showed no abnormality. Treatment with androgen in one case provided no benefit. Benign neurogenic amyotrophy in the Klinefelter's syndrome is likely to be an independent type of motor neuron disease and suggests that the X chromosome plays an important part in the biology of motor neurons.
A very rare case of complete testicular feminisation with a 47,XXY sex chromosome complement is described. The X-chromatin is positive. The subject studied, who belongs to a family in which four other members have Morris's syndrome and have a 46,XY karyotype, is a perfect phenotypic female. The endocrine situation is unique and resembles, in part, that of subjects with Klinefelter's syndrome.
Autoimmune thyroid disease is common in systemic lupus erythematosus (SLE). About 20% of patients with SLE have secondary Sjögren's syndrome.
Families with more than one patient with SLE were identified. All patients met the revised classification criteria, although SLE‐unaffected relatives were confirmed not to satisfy these criteria. Diagnosis of autoimmune thyroid disease and Sjögren's syndrome was made on the basis of a review of medical records, interview and questionnaire administered to patients with SLE, and by a questionnaire administered to SLE‐unaffected subjects.
Of a total of 1138 patients with SLE, 169 had a diagnosis of Sjögren's syndrome. Of these 50 (29.6%) patients also had autoimmune thyroid disease. Of the 939 patients with SLE with no diagnosis of Sjögren's syndrome, 119 (12.7%) had autoimmune thyroid disease (χ2 = 20.1, p = 0.000009). There was no association of a diagnosis of hypertension with secondary Sjögren's syndrome (42% vss 47%). Among 2291 SLE‐unaffected relatives, 44 had diagnosed primary Sjögren's syndrome and 16 (36.3%) of these also had autoimmune thyroid disease. 265 of 2247 (11.8%) subjects had autoimmune thyroid disease but no Sjögren's syndrome (χ2 = 24.2, p<0.001).
Autoimmune thyroid disease is found in excess among patients with SLE with a diagnosis of secondary Sjögren's syndrome, as well as among their SLE‐unaffected relatives with a diagnosis of primary Sjögren's syndrome.
Sex chromosome trisomies (SCTs) are found on amniocentesis in 2.3–3.7 per 1000 same-sex births, yet there is a limited database on which to base a prognosis. Autism has been described in postnatally diagnosed cases of Klinefelter syndrome (XXY karyotype), but the prevalence in non-referred samples, and in other trisomies, is unclear. The authors recruited the largest sample including all three SCTs to be reported to date, including children identified on prenatal screening, to clarify this issue.
Parents of children with a SCT were recruited either via prenatal screening or via a parental support group, to give a sample of 58 XXX, 19 XXY and 58 XYY cases. Parents were interviewed using the Vineland Adaptive Behavior Scales and completed questionnaires about the communicative development of children with SCTs and their siblings (42 brothers and 26 sisters).
Rates of language and communication problems were high in all three trisomies. Diagnoses of autism spectrum disorder (ASD) were found in 2/19 cases of XXY (11%) and 11/58 XYY (19%). After excluding those with an ASD diagnosis, communicative profiles indicative of mild autistic features were common, although there was wide individual variation.
Autistic features have not previously been remarked upon in studies of non-referred samples with SCTs, yet the rate is substantially above population levels in this sample, even when attention is restricted to early-identified cases. The authors hypothesise that X-linked and Y-linked neuroligins may play a significant role in the aetiology of communication impairments and ASD.
The most common sex chromosome complex in sex chromatin-positive males with Klinefelter's syndrome is XXY. When the complex is XXYY or XXXY, the clinical findings do not seem to differ materially from those seen in XXY subjects, although more patients with these intersexual chromosome complements need to be studied to establish possible phenotypical expressions of the chromosomal variants.
Two male children with an XXXXY sex chromosome abnormality are described. The data obtained from the study of these cases and five others described in the literature suggest that the XXXXY patient is likely to have congenital defects not usually seen in the common form of the Klinefelter syndrome. These include a triad of (1) skeletal anomalies (including radioulnar synostosis), (2) hypogenitalism (hypoplasia of penis and scrotum, incomplete descent of testes and defective prepubertal development of seminiferous tubules), and (3) greater risk of severe mental deficiency.
That the conclusions are based on data from a small number of patients is emphasized, together with the need for a cytogenetic survey of a large control or unselected population.
Hypostatic leg ulcers, probably secondary to vascular insufficiency, were observed in two adult men with 47,XXY Klinefelter's syndrome. The association between leg ulcers and 47,XXY Klinefelter's syndrome deserves increased attention because knowledge of the association may alert clinicians to an otherwise unsuspected chromosome abnormality.
Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving critical genetic and environmental risk factors. SLE is a relatively common disease among African American women, affecting as many as one in 250. A collection of more than 250 African American and European American pedigrees multiplex for SLE have been collected in Oklahoma over the past decade for the purpose of identifying the genetic risk factors involved in the pathogenesis of SLE. A genome scan has been performed, and interestingly, the linkage results usually dominate in families from one or the other of these ethnicities. For example, the linkage effect at 1q21-22 near FcgammaRIIA is much stronger in the African American pedigrees than in the European American pedigrees. On the other hand, a gene near the top of chromosome4 (at 4p l6-15) contributes to SLE in the European American pedigrees, but not in the African American pedigrees. The racially-specific results lead to the tentative conclusion of genetic differences associated with SLE in African Americans and European Americans. The identification of the genes responsible for the observed linkage effects will provide fundamental knowledge concerning SLE and may even provide new targets for therapy and strategies to defeat this enigmatic and difficult disease.
Kennedy's disease, an X-linked spinal and bulbar muscular atrophy, is characterized by loss of lower motor neurons. Mild sensory deficits, gynecomastia and infertility may be observed. Klinefelter's syndrome is a variation of sex chromosome disorder characterized by hypogonadism, gynecomastia and azoospermia, and the most frequent karyotype is XXY. A 55-year-old man who presented with slowly progressive and diffuse neurogenic muscle atrophy without bulbar or sensory symptoms. He also had Klinefelter's syndrome. Genetic study of Kennedy's disease was normal. Our patient differs from those with Kennedy's disease in the absence of bulbar and sensory symptoms. It is suggested that the X chromosome plays an important role in the biology of motor neurons.
Electromyogram; gynecomastia; Klinefelter's syndrome; Kennedy's disease; muscle biopsy; progressive muscular atrophy
Klinefelter's syndrome is characterized by abnormal karyotype 47, XXY and a phenotype associated with hypogonadism and gynecomastia. Often the disease can be diagnosed accidentally, when carrying out cytogenetic analysis in cases of a malignant blood disease. We present the clinical case of a patient diagnosed with acute myelomonoblastic leukemia-M4 Eo (AML- M4), where by means of classic cytogenetics a karyotype was found corresponding to Klinefelter's syndrome. Three induction courses of polychemotherapy wermade, which led to remission of the disease, documented both flowcytometrically and cytogenetically.
genetics; Klinefelter's syndrome; leukemia; remission.
A case of Klinefelter's syndrome presenting with systemic lupus erythematosus while receiving androgen replacement therapy is described. The association of systemic lupus erythematosus with Klinefelter's syndrome is discussed, particularly in terms of the effect of sex hormones.
Our goal in the present work was to determine whether male patients with untreated hypogonadism have an increased risk of developing rheumatic/autoimmune disease (RAD), and, if so, whether there is a relation to the type of hypogonadism. We carried out neuroendocrine, genetic, and rheumatologic investigations in 13 such patients and 10 healthy male 46,XY normogonadic control subjects. Age and body mass index were similar in the two groups. Nine of the 13 patients had hypergonadotropic hypogonadism (five of whom had Klinefelter's syndrome [karyotype 47,XXY]) and 4 of the 13 had hypogonadotropic hypogonadism (46,XY). Of these last four, two had Kallmann's syndrome and two had idiopathic cryptorchidism.
Eight (61%) of the 13 patients studied had RADs unrelated to the etiology of their hypogonadism. Of these, four had ankylosing spondylitis and histocompatibility B27 antigen, two had systemic lupus erythematosus (in one case associated with antiphospholipids), one had juvenile rheumatoid arthritis, and one had juvenile dermatomyositis. In comparison with the low frequencies of RADs in the general population (about 0.83%, including systemic lupus erythematosus, 0.03%; dermatomyositis, 0.04%; juvenile rheumatoid arthritis, 0.03%; ankylosing spondylitis, 0.01%; rheumatoid arthritis, 0.62%; and other RAD, 0.1%), there were surprisingly high frequencies of such disorders in this small group of patients with untreated hypogonadism (P < 0.001) and very low serum testosterone levels (P = 0.0005). The presence of RADs in these patients was independent of the etiology of their hypogonadism and was associated with marked gonadal failure with very low testosterone levels.
ankylosing spondylitis; hypogonadism; rheumatic diseases; systemic lupus erythematosus; testosterone
A 16 years old boy with Chronic Renal Failure (CRF) was not suspected of having Klinefelter’s syndrome until he complained of painful gynecomastia. He was under haemodialysis for 2 years. At first, he was in an approximately full pubertal development (P5, G5), but he had a small and a firm testis (length 2.2cm) and some degree of facial male pattern hair. He also had a decreased upper to lower body segment ratio and despite having chronic renal failure, he was taller than his parents and siblings. His laboratory tests showed high levels of FSH and normal levels of LH and testosterone. With regards to all these findings, we suspected that there might be an occult Klinefelter’s syndrome. So, we made his karyotype that showed a 47XXY pattern. Because there are only a few number of cases that have occult Klinefelter’s syndrome in the basis of chronic renal failure, we decided to report this case.
CRF; Occult klinefelter; Haemodialysis
A 14-month-old boy with double aneuploidy and a double aortic arch suffered from frequently recurrent severe feeding and respiratory problems. Chromosomal analysis showed a 48,XXY + 21 karyotype: a double aneuploidy of Down syndrome (DS) and Klinefelter syndrome (KS). Only four cases of double aneuploidy (DS + KS) associated with congenital heart defects have been published of which none had a double aortic arch. Our case report should draw attention to the possibility of a double aortic arch in patients with severe feeding and respiratory problems and a double aneuploidy.
Double aneuploidy; Down syndrome; Klinefelter syndrome; Double aortic arch; Vascular ring
We describe a man with Becker muscular dystrophy whose weakness was minimal in contrast to that of his more severely affected nephews. This man had a Klinefelter karyotype (47,XXY) and his mild symptoms may be attributed to him being heterozygous for the muscular dystrophy gene. This is the first report of a person with both Klinefelter's syndrome and Becker muscular dystrophy. This combination may be one explanation for the variable expression of X linked muscular dystrophy noted in some pedigrees.
Over 100 cases of 49,XXXXY syndrome have been published to date. Classic findings include radioulnar synostosis, hypogonadism, and mental retardation. The majority of reported cases have not distinguished the 49,XXXXY syndrome from Klinefelter syndrome (47,XXY), and these patients are frequently labelled as having Klinefelter syndrome or as being a "Klinefelter variant." Because of distinct clinical features, we delineate the 49,XXXXY syndrome as separate from Klinefelter syndrome, and emphasise the prevalence of congenital heart defects. We also report three new cases of 49,XXXXY syndrome and briefly discuss patient management.