DOCSLIB.ORG

Klinefelter Syndrome DANIEL J

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Klinefelter Syndrome DANIEL J ANNUAL CLINICAL FOCUS Klinefelter Syndrome DANIEL J. WATTENDORF, MAJ, MC, USAF, and MAXIMILIAN MUENKE, M.D. National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland To complement the 2005 Annual Clinical Focus on medical genom- ics, AFP is publishing a series of short reviews on genetic syndromes. This series was designed to increase awareness of these diseases so that family physicians can recognize and diagnose children with these disorders and understand the kind of care they might require in the future. This review discusses Klinefelter syndrome. (Am Fam Physician 2005;72:2259-62 Copyright © 2005 American Academy of Family Physicians.) This article exem- linefelter syndrome is caused by Body habitus may be feminized (Figure 1). plifies the AAFP 2005 an additional X chromosome in In childhood, when there is a relative quies- Annual Clinical Focus on the legal, social, clinical, males (47,XXY). Clinical findings cence in the hormonal milieu, ascertainment and ethical issues of medi- are nonspecific during childhood; of the syndrome may be difficult because the cal genomics. Kthus, the diagnosis commonly is made during effects of hypogonadism (i.e., small external A glossary of genomics adolescence or adulthood in males who have genitalia and firm testes) may be subtle or terms is available online small testes with hypergonadotropic hypogo- not present at all. at http://www.aafp.org/ nadism and gynecomastia. Virtually all men Persistent androgen deficiency in adult- afpgenglossary.xml. with Klinefelter syndrome are infertile. hood may result in loss of libido, decreased muscle bulk and tone, decreased bone Epidemiology mineral density, a propensity for thrombo- Approximately one in 1,000 boys is born with embolism, and an increased risk of mor- an additional X chromosome—47,XXY, the tality from diabetic and cardiovascular karyotype that causes Klinefelter syndrome.1 complications.4 This karyotype is detected at or before birth in 10 percent of affected boys, and it is found during adulthood in 25 percent of affected TABLE 1 men.2 Almost all men with a 47,XXY karyo- Klinefelter Syndrome: Characteristic type will be infertile; Klinefelter syndrome Clinical Findings accounts for 3 percent of male infertility.3 Klinefelter syndrome is common in infertile Infertility (azoospermia or oligospermia) men with oligospermia or azoospermia (5 to Small, firm testes 10 percent).2 Hypergonadotropic hypogonadism Gynecomastia Clinical Presentation Tall, slender body habitus with long legs The most overt phenotypic features of Kline- and shorter torso felter syndrome are caused by testosterone Osteoporosis (in young or middle-age men) deficiency and, directly or indirectly, by Motor delay or dysfunction unsuppressed follicle-stimulating and lutein- Speech and language difficulties izing hormones. Affected men typically have Attention deficits (in decreasing order of frequency): infertility, Learning disabilities small testes, decreased facial hair, gynecomas- Dyslexia or reading dysfunction tia, decreased pubic hair, and a small penis Psychosocial or behavioral problems (Table 1).2 Because of their long legs, men with Klinefelter syndrome often are taller Information from reference 2. than predicted based on parental height. December 1, 2005 U Volume 72, Number 11 www.aafp.org/afp American Family Physician 2259 Klinefelter Syndrome speech, and language), Klinefelter syndrome Normal karyotype Klinefelter syndrome (46,XY) (47,XXY) has been identified in 0.4 percent of boys with special education needs and no known diagnosis, and in 1.2 percent of boys with Y Y mental retardation of unknown etiology. In X X X these cases, the boys initially were referred for consideration of fragile X syndrome.6,7 Tall stature Of note, the 0.4 percent of boys with Kline- Narrow shoulders felter syndrome in the special-education Gynecomastia Small testes cohort is likely to represent less than half the Infertility actual prevalence, because only paternally acquired disease was identified. Magnetic resonance imaging has identi- fied a specific brain morphology associated with Klinefelter syndrome.8 An increased risk of psychiatric disorders also has been reported in affected men.9 Diagnosis Because most boys with Klinefelter syndrome appear similar to boys with normal karyo- types, the disorder typically is identified in adulthood, when infertility or gynecomas- tia are common presentations. However, ILLUSTRATION BY DARRYL LEJA DARRYL BY ILLUSTRATION by this time, a therapeutic window during Figure 1. Characteristic clinical findings in men with Klinefelter syn- adolescence for treatment of hypogonadism, drome. Note that there are no facial characteristics that suggest a diagnosis of Klinefelter syndrome. Therefore, particular attention to cognitive impairments, and psychosocial fac- physical examination of the body habitus is necessary for diagnostic tors has been missed. Late or incomplete consideration. puberty should prompt further examination. Testicular size can be measured with a Prader Specific cognitive deficits in language orchidometer or ultrasonography. Middle comprehension and executive functioning school–age boys with Klinefelter syndrome are part of the Klinefelter syndrome pheno- often will have elevated follicle-stimulat- type.5 Although most studies describe only ing and luteinizing hormone levels and low mild cognitive impairment (e.g., mild global plasma testosterone levels. Subclinical values delay in gross and fine motor development, on laboratory indices may be found in these patients; therefore, a karyotype with instruc- tions to count sex chromosomes in 50 cells The Authors is useful for diagnosis, especially in patients DANIEL J. WATTENDORF, MAJ, MC, USAF, is a family physician and clinical with mosaicism. geneticist. He is assistant professor in the Department of Family Medicine at the Uniformed Services University of the Health Sciences, F. Edward Hébert School of Causes of Klinefelter Syndrome Medicine, Bethesda, Md., and attending clinical geneticist at the National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda. The additional sex chromosomes in men with Klinefelter syndrome results from non- MAXIMILIAN MUENKE, M.D., is a pediatrician and clinical geneticist. He is disjunction during meiosis and may have chief of the Medical Genetics Branch at the National Human Genome Research Institute, NIH, and director of the medical genetics residency and fellowship a paternal (50 to 60 percent) or maternal training programs at NIH. (40 to 50 percent) origin. This contrasts with Down syndrome, which is caused pre- Address correspondence to Maximilian Muenke, M.D., Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, 35 dominantly by maternal nondisjunction Convent Dr. – MSC 3717, Building 35, Room 1B-203, Bethesda, MD 20892-3717 and inheritance of the extra chromosome (e-mail: [email protected]). Reprints are not available from the authors. 21 from the mother. 2260 American Family Physician www.aafp.org/afp Volume 72, Number 11 U December 1, 2005 Klinefelter Syndrome Although Klinefelter syndrome encom- The prepubertal testosterone deficit results passes the specific clinical consequences in impaired bone mineral density and skel- observed in men with an XXY karyotype, etal muscle development. Decreased energy there are variant karyotypes that can include and libido, which are associated with post- additional X chromosomes (e.g., XXXY, pubertal testosterone deficit, improve with XXXXY) or additional X and Y chromo- hormone therapy and often are accompa- somes (e.g., XXYY). Men with these karyo- nied by improved confidence and sense of types have similar but often more severe well-being.10 phenotypes compared with those with the Androgen therapy should be started when XXY karyotype. there is direct laboratory evidence of a tes- Physical manifestations of Klinefelter syn- tosterone deficit or when hypergonadotro- drome are relatively moderate compared phism, which suggests such a deficit, is with autosomal trisomies (e.g., Down syn- present. This may occur by the time the drome) because when additional X chro- patient begins middle school (i.e., 12 to mosomes are present, one is predominantly 14 years of age). Physical differences in males inactivated. However, the entire X chromo- with Klinefelter syndrome often are evident some is not inactivated. As the number of after the onset of puberty. However, the X chromosomes increases, the phenotypic characteristic phenotypic findings (e.g., lack severity increases as well. As a result, cogni- of gonadal development; sparse or absent tive and gonadal development is impaired, facial hair; and thin, long-limbed body habi- and cardiovascular and skeletal manifesta- tus) usually are subtle. Consideration of tions often are present. Klinefelter syndrome as a diagnosis and Mosaicism occurs in 15 percent of men investigation with a standard karyotype are with an additional X chromosome and gen- important because of the therapeutic benefit erally results in a milder phenotype. When of testosterone supplementation. Clinical mosaicism occurs, cells with two or more suspicion warrants diagnostic investigation karyotypes are distributed. Most often, a to ensure appropriate surveillance for tes- normal chromosome number (46,XY) is tosterone deficit. identified in cells from a sample that also Because gynecomastia predisposes men to contains hyperdiploid cells (i.e., a Kline- breast cancer—the
Load more

Recommended publications
  • Klinefelter, Turner & Down Syndrome
    Klinefelter, Turner & Down Syndrome A brief discussion of gamete forma2on, Mitosis and Meiosis: h7ps://www.youtube.com/watch?v=zGVBAHAsjJM Non-disjunction in Meiosis: • Nondisjunction "not coming apart" is the failure of a chromosome pair to separate properly during meiosis 1, or of two chromatids of a chromosome to separate properly during meiosis 2 or mitosis. • Can effect each pair. • Not a rare event. • As a result, one daughter cell has two chromosomes or two chromatids and the other has none • The result of this error is ANEUPLOIDY. 4 haploid gametes 2 gametes with diploid 2 gametes with haploid number of x and 2 lacking number of X chromosome, 1 x chromosome gamete with diploid number of X chromosome, and 1 gamete lacking X chromosome MEIOSIS MITOSIS Nondisjunc2on at meiosis 1 = All gametes will be abnormal Nondisjunc2on at meiosis 2 = Half of the gametes are normal (%50 normal and %50 abnormal) Down’s Syndrome • Karyotype: 47, XY, +21 Three copies of chromosome 21 (21 trisomy) • The incidence of trisomy 21 rises sharply with increasing maternal age (above 37), but Down syndrome can also be the result of nondisjunction of the father's chromosome 21 (%15 of cases) • A small proportion of cases is mosaic* and probably arise from a non-disjunction event in early zygotic division. *“Mosaicism, used to describe the presence of more than one type of cells in a person. For example, when a baby is born with Down syndrome, the doctor will take a blood sample to perform a chromosome study. Typically, 20 different cells are analyzed.
    [Show full text]
  • NIPT Fact Sheet
    Victorian Clinical Genetics Services Murdoch Childrens Research Institute The Royal Children's Hospital Flemington Road, Parkville VIC 3052 P (03) 8341 6201 W vcgs.org.au NIPT fact sheet High risk for XXY This fact sheet is for women and their partners who receive a high risk result for XXY from the perceptTM non-invasive prenatal test (NIPT) Possible explanations for this offered by Victorian Clinical Genetics Services (VCGS). This information high risk result: may not be applicable to test results reported by other NIPT service There is a high chance that the baby has XXY. providers. However, the only way to provide a definitive As part of the service offered by VCGS, women and couples have diagnosis is to have a diagnostic procedure the opportunity to discuss their result with a genetic counsellor at no (CVS or amniocentesis) with chromosome additional cost. Genetic counsellors are experts in assisting people to testing. understand genetic test results and make informed decisions about In some cases, high risk results for XXY may further testing options. represent ‘false positive’ test results. A false positive result means that although NIPT indicates a high risk of XXY, the baby does not What does this result mean? have this condition. NIPT is a way for women to get an accurate estimate of the chance that their baby has one of the most common chromosome conditions: Possible causes of false positive results trisomy 21 (Down syndrome), trisomy 18 and trisomy 13. The test for XXY from NIPT include: may also detect whether there are extra or missing copies of the sex chromosomes, X and Y.
    [Show full text]
  • Phenotype Manifestations of Polysomy X at Males
    PHENOTYPE MANIFESTATIONS OF POLYSOMY X AT MALES Amra Ćatović* &Centre for Human Genetics, Faculty of Medicine, University of Sarajevo, Čekaluša , Sarajevo, Bosnia and Herzegovina * Corresponding author Abstract Klinefelter Syndrome is the most frequent form of male hypogonadism. It is an endocrine disorder based on sex chromosome aneuploidy. Infertility and gynaecomastia are the two most common symptoms that lead to diagnosis. Diagnosis of Klinefelter syndrome is made by karyotyping. Over years period (-) patients have been sent to “Center for Human Genetics” of Faculty of Medicine in Sarajevo from diff erent medical centres within Federation of Bosnia and Herzegovina with diagnosis suspecta Klinefelter syndrome, azoo- spermia, sterilitas primaria and hypogonadism for cytogenetic evaluation. Normal karyotype was found in (,) subjects, and karyotype was changed in (,) subjects. Polysomy X was found in (,) examinees. Polysomy X was expressed at the age of sexual maturity in the majority of the cases. Our results suggest that indication for chromosomal evaluation needs to be established at a very young age. KEY WORDS: polysomy X, hypogonadism, infertility Introduction Structural changes in gonosomes (X and Y) cause different distribution of genes, which may be exhibited in various phenotypes. Numerical aberrations of gonosomes have specific pattern of phenotype characteristics, which can be classified as clini- cal syndrome. Incidence of gonosome aberrations in males is / male newborn (). Klinefelter syndrome is the most common chromosomal disorder associated with male hypogonadism. According to different authors incidence is / male newborns (), /- (), and even / (). Very high incidence indicates that the zygotes with Klinefelter syndrome are more vital than those with other chromosomal aberrations. BOSNIAN JOURNAL OF BASIC MEDICAL SCIENCES 2008; 8 (3): 287-290 AMRA ĆATOVIĆ: PHENOTYPE MANIFESTATIONS OF POLYSOMY X AT MALES In , Klinefelter et al.
    [Show full text]
  • RD-Action Matchmaker – Summary of Disease Expertise Recorded Under
    Summary of disease expertise recorded via RD-ACTION Matchmaker under each Thematic Grouping and EURORDIS Members’ Thematic Grouping Thematic Reported expertise of those completing the EURORDIS Member perspectives on Grouping matchmaker under each heading Grouping RD Thematically Rare Bone Achondroplasia/Hypochondroplasia Achondroplasia Amelia skeletal dysplasia’s including Achondroplasia/Growth hormone cleidocranial dysostosis, arthrogryposis deficiency/MPS/Turner Brachydactyly chondrodysplasia punctate Fibrous dysplasia of bone Collagenopathy and oncologic disease such as Fibrodysplasia ossificans progressive Li-Fraumeni syndrome Osteogenesis imperfecta Congenital hand and fore-foot conditions Sterno Costo Clavicular Hyperostosis Disorders of Sex Development Duchenne Muscular Dystrophy Ehlers –Danlos syndrome Fibrodysplasia Ossificans Progressiva Growth disorders Hypoparathyroidism Hypophosphatemic rickets & Nutritional Rickets Hypophosphatasia Jeune’s syndrome Limb reduction defects Madelung disease Metabolic Osteoporosis Multiple Hereditary Exostoses Osteogenesis imperfecta Osteoporosis Paediatric Osteoporosis Paget’s disease Phocomelia Pseudohypoparathyroidism Radial dysplasia Skeletal dysplasia Thanatophoric dwarfism Ulna dysplasia Rare Cancer and Adrenocortical tumours Acute monoblastic leukaemia Tumours Carcinoid tumours Brain tumour Craniopharyngioma Colon cancer, familial nonpolyposis Embryonal tumours of CNS Craniopharyngioma Ependymoma Desmoid disease Epithelial thymic tumours in
    [Show full text]
  • Rare Double Aneuploidy in Down Syndrome (Down- Klinefelter Syndrome)
    Research Article Journal of Molecular and Genetic Volume 14:2, 2020 DOI: 10.37421/jmgm.2020.14.444 Medicine ISSN: 1747-0862 Open Access Rare Double Aneuploidy in Down Syndrome (Down- Klinefelter Syndrome) Al-Buali Majed J1*, Al-Nahwi Fawatim A2, Al-Nowaiser Naziha A2, Al-Ali Rhaya A2, Al-Khamis Abdullah H2 and Al-Bahrani Hassan M2 1Deputy Chairman of Medical Genetic Unite, Pediatrics Department, Maternity Children Hospital Al-hassa, Hofuf, Saudi Arabia 2Pediatrics Resident, Pediatrics Department, Maternity Children Hospital Alhassa, Hofuf, Saudi Arabia Abstract Background: The chromosomal aneuploidy described as Cytogenetic condition characterized by abnormality in numbers of the chromosome. Aneuploid patient either trisomy or monosomy, can occur in both sex chromosomes as well as autosome chromosomes. However, double aneuploidies involving both sex and autosome chromosomes relatively a rare phenomenon. In present study, we reported a double aneuploidy (Down-Klinefelter syndrome) in infant from Saudi Arabia. Materials and Methods: In the present investigation, chromosomal analysis (standard chromosomal karyotyping) and fluorescence in situ hybridization (FISH) were performed according to the standard protocols. Results: Here, we report a single affected individual (boy) having Saudi origin, suffering from double chromosomal aneuploidy. The main presenting complaint is the obvious dysmorphic features suggesting Down syndrome. Chromosomal analysis and FISH revealed 48,XXY,+21, show the presence of three copies of chromosome 21, two copies of X chromosome and one copy of Y chromosome chromosomes. Conclusion: Patients with Down syndrome must be tested for other associated sex chromosome aneuploidies. Hence, proper diagnosis is needed for proper management and the cytogenetic tests should be performed as the first diagnostic approach.
    [Show full text]
  • Turner Syndrome
    Sex Chromosome Abnormalities Turner Syndrome Turner syndrome occurs in 1/2500 live births. It is caused by a partial or complete absence of one of the X chromosomes in a female. A single X chromosome is the most common cause of miscarriage. It is believed 99% of all 45,X conceptions result in miscarriage. The fetuses are often severely hydropic (Figure 1). When a baby is born with Turner syndrome there are often few features. One feature that can be noted during the newborn period is puffy hands and puffy feet (Figure 3). Broad chest can also be an early sign. The majority of females have normal intelligence. There are some deficits in visual special abilities. Most females with Turner syndrome present at age 5-6 with short stature. Features include short stature, webbing of the neck, shield chest, shortened 4 th metacarpal and madelung deformity of the forearm. There is also a risk of renal anomalies including horseshoe kidneys. Adolescent girls with Turner syndrome often have failure of puberty, absence of spontaneous breast development and primary amenorrhea. Approximately 60% of females with Turner syndrome have a single X chromosome in all cells analyzed (Figure 2). Twenty percent are mosaic in which some of their cells have 2 X chromosomes while some have a single X. A small percentage of females with Turner syndrome have a part of one X chromosome in a ring formation. These females are at risk of developmental delay. Figure 1. Figure 2. Figure 3. Patients with Turner syndrome are at increased risk for a number of medical issues including renal anomalies (most common horseshoe kidneys), hearing impairment, and congenital heart defects.
    [Show full text]
  • Klinefelter Syndrome
    FACT SHEET Klinefelter Syndrome WHAT IS KLINEFELTER WHAT ARE THE SIGNS AND SYMPTOMS SYNDROME? OF KLINEFELTER SYNDROME? Signs and symptoms can vary. Some males have no symptoms Klinefelter syndrome is a group of conditions that affects but a doctor will be able to see subtle physical signs of the the health of males who are born with at least one extra X syndrome. Many males are not diagnosed until puberty or chromosome. Chromosomes, found in all body cells, contain adulthood. As many as two-thirds of men with the syndrome may genes. Genes provide specific instructions for body characteristics never be diagnosed. Many men with mosaic Klinefetler syndrome and functions. For example, some genes determine height and have few obvious signs except very small testicles. hair color. Other genes influence language skills and reproductive functions. Each person typically has 23 pairs of chromosomes. One of these pairs (sex chromosomes) determines a person’s sex. A baby with two X chromosomes (XX) is female. A baby with one X chromosome and one Y chromosome (XY) is male. Most males with Klinefelter syndrome, also called XXY males, have two X chromosomes instead of one. The extra X usually occurs in all body cells. Sometimes the extra X only occurs in some cells, resulting in a less severe form of the syndrome (called mosaic Klinefelter syndrome). Rarely, a more severe form occurs when there are two or more extra X chromosomes. DID YOU KNOW? Klinefelter syndrome is the most common sex-chromosome abnormality, affecting about one in every 500 to 700 men. WHAT CAUSES KLINEFELTER SYNDROME? The addition of extra chromosomes seems to occur by chance.
    [Show full text]
  • ORD Resources Report
    Resources and their URL's 12/1/2013 Resource Name: Resource URL: 1 in 9: The Long Island Breast Cancer Action Coalition http://www.1in9.org 11q Research and Resource Group http://www.11qusa.org 1p36 Deletion Support & Awareness http://www.1p36dsa.org 22q11 Ireland http://www.22q11ireland.org 22qcentral.org http://22qcentral.org 2q23.org http://2q23.org/ 4p- Support Group http://www.4p-supportgroup.org/ 4th Angel Mentoring Program http://www.4thangel.org 5p- Society http://www.fivepminus.org A Foundation Building Strength http://www.buildingstrength.org A National Support group for Arthrogryposis Multiplex http://www.avenuesforamc.com Congenita (AVENUES) A Place to Remember http://www.aplacetoremember.com/ Aarons Ohtahara http://www.ohtahara.org/ About Special Kids http://www.aboutspecialkids.org/ AboutFace International http://aboutface.ca/ AboutFace USA http://www.aboutfaceusa.org Accelerate Brain Cancer Cure http://www.abc2.org Accelerated Cure Project for Multiple Sclerosis http://www.acceleratedcure.org Accord Alliance http://www.accordalliance.org/ Achalasia 101 http://achalasia.us/ Acid Maltase Deficiency Association (AMDA) http://www.amda-pompe.org Acoustic Neuroma Association http://anausa.org/ Addison's Disease Self Help Group http://www.addisons.org.uk/ Adenoid Cystic Carcinoma Organization International http://www.accoi.org/ Adenoid Cystic Carcinoma Research Foundation http://www.accrf.org/ Advocacy for Neuroacanthocytosis Patients http://www.naadvocacy.org Advocacy for Patients with Chronic Illness, Inc. http://www.advocacyforpatients.org
    [Show full text]
  • Prenatal Aneuploidy FISH Testing
    Lab Management Guidelines V1.0.2020 Prenatal Aneuploidy FISH Testing MOL.CS.218.A v1.0.2020 Procedures addressed The inclusion of any procedure code in this table does not imply that the code is under management or requires prior authorization. Refer to the specific Health Plan's procedure code list for management requirements. Procedures addressed by this Procedure codes guideline FISH Analysis for Aneuploidy 88271 88274 88275 What is a chromosome abnormality Definition A chromosome abnormality is any difference in the structure, arrangement, or amount of genetic material packaged into the chromosomes.1 Aneuploidy refers to an abnormal number of chromosomes (i.e. extra or missing).1 Humans usually have 23 pairs of chromosomes. Each chromosome has a characteristic appearance that should be the same in each person. Chromosome abnormalities can lead to a variety of developmental and reproductive disorders. Common chromosome abnormalities that affect development include: Down syndrome (trisomy 21), trisomy 18, trisomy 13, Turner syndrome, and Klinefelter syndrome. About 1 in 200 newborns has some type of chromosome abnormality2 and a higher percentage of pregnancies are affected but lost during pregnancy. According to the American College of Obstetricians and Gynecologists (ACOG), “Fetuses affected with Down syndrome often do not survive pregnancy; between the first trimester and full term, an estimated 43% of pregnancies end in miscarriage or stillbirth.” 3 The risk of having a child with an extra chromosome, notably Down syndrome, increases as a woman gets older.3 However, many babies with Down syndrome are born to women under 35 and the risk of having a child with other types of chromosome abnormalities, such as Turner syndrome, is not related to maternal age.
    [Show full text]
  • Neurological Syndromes
    Neurological Syndromes J. Gordon Millichap Neurological Syndromes A Clinical Guide to Symptoms and Diagnosis J. Gordon Millichap, MD., FRCP Professor Emeritus of Pediatrics and Neurology Northwestern University Feinberg School of Medicine Chicago, IL, USA Pediatric Neurologist Ann & Robert H. Lurie Children’s Hospital of Chicago Chicago , IL , USA ISBN 978-1-4614-7785-3 ISBN 978-1-4614-7786-0 (eBook) DOI 10.1007/978-1-4614-7786-0 Springer New York Heidelberg Dordrecht London Library of Congress Control Number: 2013943276 © Springer Science+Business Media New York 2013 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifi cally for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc.
    [Show full text]
  • SEX-CHROMOSOME ABNORMALITIES 17.4% and the Range 8-53%
    220 JAN. 1962 SEX CHROMOSOMES AND MENTAL DEFICIENCY BDrs 27, MEDICAL JOURNAL frequency of chromatin-positive nuclei in females was SEX-CHROMOSOME ABNORMALITIES 17.4% and the range 8-53%. One female (Case 1) IN A POPULATION OF MENTALLY showed a high percentage (10%) of double chromatin DEFECTIVE CHILDREN masses (Fig. 1). Another female was found to have several somatic characteristics of "Turner's syn- BY drome" and nor- J. L. HAMERTON, B.Sc. mal female sex- ~ ~ chromatin pattern GEORGIANA M. JAGIELLO,* A.B., M.D. (Case 2). The Paediatric Research Unit, Guy's Hospital Medical School, London results of sex chromatin, neu- AND trophil counts B. H. KIRMAN, M.D., D.P.M. and chromosome analyses ofmthese Director of Research, Fountain Hospital, Tooting Grove, London three patientar shown in Table o In the past few years a number of surveys using the One boy with a5 buccal-smear method have been made on various normal male buc- populations both of normal and of mentally defective cal smear and V individuals (Prader et al., 1958; Moore, 1959; Ferguson- hypospadias .was Smith, 1959; Fraser et al., 1960; Barr et al., 1960; found to have a Israelsohn and Taylor, 1961). In the present paper we normal m a e Fio. l.-Case 1. Nucleus of buccal report the nuclear sex findings of the entire Fountain karyotype. mucosa cell, showing two sex-chromatin Hospital population of low-grade mentally defective TABLE II.-Chromosome Count Distribution in the Three children. In three subjects a sex-chromosome abnor- Abnormal Cases mality appeared likely and their clinical and cytological Sex- findings are described in detail.
    [Show full text]
  • Klinefelter Syndrome
    Klinefelter Syndrome Carla Fedor, RN -------------------------------------------------------------------------------- Introduction In 1942, Dr. Harry Klinefelter and his coworkers first described the combination of features that has come to be recognized as Klinefelter Syndrome. By the late 1950’s, researchers discovered that men with this group of symptoms had an extra sex chromosome, XXY instead of the usual male arrangement of XY. Although, XXY is common, the syndrome itself is uncommon. Many men live out their lives without ever even suspecting that they have an additional chromosome. For this reason, the term Klinefelter syndrome" has fallen out of favor with the medical community and many experts prefer to describe males having an extra chromosome as "XXY males." Chromosomes are carriers of DNA, the hereditary material. Men and women usually have 2 sex chromosomes. Women inherit 2 X chromosomes, one from each parent. Men inherit an X chromosome from their mother and a Y chromosome from their father. Causes Klinefelter’s syndrome is caused by an extra X chromosome and affects only males. No one knows what puts a couple at risk for conceiving an XXY child. A biological accident occurs during a process called meiosis causing XXY. Meiosis is experienced by all cells which will become an egg or sperm. Before meiosis is completed, chromosomes pair and exchange bits of genetic material. In women, the X chromosomes from each parent form a pair. In men, the X from the mother and the Y chromosomes from the father, form a pair. After the exchange, the chromosomes separate and meiosis continues. In some cases, the two X chromosomes or the X and Y chromosomes fail to pair and fail to exchange genetic material.
    [Show full text]