What is Klinefelter's Syndrome (KS)Contentsq Illnesses, physical conditions and emotional / behavioural aspects q Biology of male reproductive organs and testosterone q Do I need testosterone treatment q Is there a link between KS and criminality
What is KSIntroduction
This sheet seeks to
provide not only more up-to-date information about Klinefelter's
syndrome (KS) but also to give some background as to why people have
KS and the reasons for their infertility.
The information has been obtained from a wide variety of sources
and this sheet aims to present it in a matter of fact manner. Throughout this document the emphasis is on
the word may. The problems
given in this document do not represent everyone with KS. It states what problems may occur in some
individuals. Some may have one or two
of the problems, others several and yet others still have none except
infertility. Many men with KS live normal
lives, oblivious to the fact that they have KS.
Of those who find out, it is often when they seek help
for infertility, which may be their only problem.
Many are able to do ordinary jobs, either as employees,
self-employed or even employers, in both the public and private sectors,
whether or not they also have other conditions that may impair them. Many KS men also get married or live in other
relationships. Many KS males have medical
problems that are probably unconnected with having KS and this should
be borne in mind when reading this sheet. Basic
genetics
Klinefelter's syndrome
is named after Harry F. Klinefelter (cline-felter) who first described
the syndrome in the USA in 1942.[i] It is a genetic disorder that only affects
boys and men. Normally a person, whether
male or female, has a total of 46 chromosomes in the nucleus, which
is the control centre of each cell. Chromosomes are the genetic material
that contain the code of life: Deoxyribonucleic acid, better known
as DNA. Of those 46 chromosomes, 44 are
grouped in a total of 22 pairs and are called autosomes,
the name given to the non-sex determining chromosomes that determine
other characteristics. In addition
there are normally two sex chromosomes, females having two X chromosomes
and males having one X and one Y. Each chromosome is made up of genes,
each of which has a specific role to perform.
The Y chromosome contains the male determining gene. Of the 46 chromosomes, half come from the
mother and half from the father. A normal
male would have 44 autosomes and the X and Y sex chromosomes, making
a total of 46. This is expressed as 46,XY and is known as that individual's
karyotype (carry-o-type). In
Klinefelter's syndrome however, due to one of nature's accidents,
when the male sperm fuses with the female egg, the fetal cells have
at least one extra X chromosome. The
most common number of chromosomes found in KS is 47, that is 44
autosomes and 3 sex chromosomes giving a karyotype of 47,XXY. The extra X chromosome
can come from either a sperm or an egg, with a 50:50 chance. However
as maternal age increases so does the risk of having a boy with KS. The same risk does not however occur as men
get older. Because KS is not passed on
but occurs by accident, it is said to be congenital, which means that
it is not inherited, that is, it is not an hereditary
disorder. This means that the parents
of a boy who has Klinefelter's syndrome need not be anxious about
having more children as the likelihood of having another KS boy is
minimal. What
is a mosaic/mosaicism ?
Some KS males have
what is known as mosaicism (mose-aia-sisem) which
means that some of the cells in their body are ordinary 46,XY whilst
others are, for example, 47,XXY. This
example would be expressed as 46,XY/47,XXY.
Some of these individuals, because of where the normal 46,XY
cells are located, are able to produce sperm and father children,
whereas the majority who are non-mosaic are sterile, that is, they
are unable to produce sperm and father children. Basic statistics
q
KS is estimated
to be found in 1 in 1000 (0.1%)[ii] [iii] of live male births, but other studies have suggested that
the figure may be as high as 1 in 700 (approximately 0.14%)[iv] q
The most common karyotype is 47,XXY [v] q
A minority of KS
males have a relatively low IQ below 80 [vi]
(a measure of intelligence relative to the rest of the population;
the average is normally 100, give or take 15) q
Delayed language development occurs in 50% of cases [vii],[viii] q
Breast development,
known as gynæcomastia (guy-na-co-mastia) occurs
in some cases, however during q
Examples[x] of other KS karyotypes
are: 48,XXXY, 46,XX (male), 46,XxY, 46,XX/47,XXY
Boys with KSBoys with KS have
a normal male body shape and are thus referred to as being phenotypically
(fee-no-typically) male. They may experience learning difficulties,
especially with verbal or spoken skills, which may require appropriate
speech therapy. They may have difficulty
in concentrating for more than a few minutes on any single topic. They may have problems in socialising with
other children of their own age group. Boys
with KS may have difficulties in specific areas of learning, especially
those that are based upon a facility with language. This affects their ability to learn to read
and spell, as well as their ability to learn arithmetic skills. Remedial teaching (learning support) may be
beneficial for such children, and a Statement of Special Educational
Needs is often appropriate[xi]. At puberty, blood testosterone
levels are normal initially but may fail to rise into the normal adult
range from age 14 onwards. A boy's hips
may develop fatty deposits (although this can occur in non-KS males)
so that the boys assume more of a female pear shape (described as
eunuchoid) and they may develop breast enlargement,
though this is also a common finding in non-KS boys. If testosterone is low, muscle development
and beard growth may be reduced, and sexual interest lowered. Before puberty a KS boy's testes have a lower
number of sperm producing cells (spermatogonia) than his peers, but
after puberty has begun fibrosis & hyalinization (hialin-i-zation)
of the seminiferous (semi-nif-er-ous) tubules begins, a process which
results in sterility. In simple terms
hyalinization means that the seminiferous tubules become filled with
a substance called hyalin which hardens & blocks the tubules. Fibrosis means that the tissue or cells surrounding
the tubules (called connective tissue) shrink & become permanently
scarred or damaged. During puberty a KS
boy may begin to have problems at school if he has to participate in
school sport. If physical differences
are present, these can attract the unpleasant attention of his classmates
and can result in teasing and social isolation.
Before puberty it is desirable to discuss this in confidence with
his headteacher and those other members of staff who need to know. Should gynæcomastia develop to a degree
where it causes unhappiness to the boy, testosterone treatment and
surgery should be considered and the implications fully discussed
and understood by an affected adolescent before any final decision
is taken. If surgery is chosen, it is
important to ensure that the surgeon who will be operating has some
experience in doing so, as poor surgery can create worse psychological
problems than existed prior to the operation.
Men with KSMen with KS are
usually sterile. They tend to have longer arms and legs and tend to
be taller than their peers. Lack of emotion,
fatigue and apathy are common[xii]
and other problems such as an increased tendency to develop psychiatric
disorders,[xiii] may occur as a result
of the syndrome. General information -
introduction
A number of other
characteristics may be associated with Klinefelter's syndrome that are
dealt with briefly. In the past, too much attention may have been
paid to problems affecting one or two individuals who also happened
to have KS, which has led to suggestions of associations between the
syndrome and other diseases (however see below).
Follow-up investigations have not necessarily confirmed such
findings, demonstrating a need for both parents, affected individuals
and those professionals working with them to be open minded and not
take what they read or hear necessarily as fact.
Corroboration of research by other researchers is desirable
before any suggested association between KS and something else is
accepted. An additional problem
often encountered is inaccurate information published in some medical
reference books aimed at the general public.
Authors have not always checked their facts and this had led to
unnecessary anxiety in readers. Similar
problems are beginning to appear with some medical information on
the internet, with opinion sometimes presented as fact. Illnesses,
physical conditions and emotional / behavioural aspects
Disorders of the body's defence system with antibodies attacking the
body itself, appear to be more common in KS with a greater tendency
to develop breathing (ie respiratory) disorders such
as asthma. There seems to be a
higher risk of developing diseases affecting the veins:
hypostatic leg ulcers and thrombophlebitis
(throm-bo-flea-bite-is) seem to be more common.
In thrombophlebitis the wall of a vein can become inflamed
and this can lead to the liquid blood becoming solidified and causing
a blood clot that impedes the progress of the blood in the affected
area There appears to be a higher risk
of developing osteoporosis (also known as brittle bone disease) in which the bones gradually weaken
and are more likely to break. Men with
KS who only have moderately low levels of natural testosterone may
have normal bone density whilst those with lower bone density seem
to have an increased bone turnover.[xiv] Treatment with testosterone (more later)
may prevent this from developing. However
there is evidence which suggests that only early testosterone treatment
prevents reduced bone density. Later
treatment (after puberty) seems to offer no benefits.[xv],[xvi]
Decreasing bone mass which can lead to osteoporosis, can be
automatically measured by a bone density scanner.
A new test has also been developed which analyses a urine
sample for the presence of a collagen breakdown product, which indicates
the development of osteoporosis.[xvii] It has been suggested that diabetes mellitus is associated with Klinefelter's syndrome
but the connection may be linked with the greater tendency for KS
men to be overweight as this disorder can occur in such individuals. As yet there is no sound evidence linking
diabetes with KS. There is a slightly higher risk of developing the following
two types of cancer. Male
breast cancer is more common in KS than in the normal male population. Almost 1% of all breast cancers are in men.[xviii]
Breast cancer is 20 times more common in KS than in non-KS males. This means that roughly 3% of KS men will
develop breast cancer[xix]. Whilst this poses a risk, it needs to be looked
at in the context that it is estimated that 1 in 12 (around 9% of)
women will develop breast cancer over their lifetime.[xx]
That is, they have three times the risk KS men have. The reported average age the cancer starts
is later than that found in women who develop breast cancer.[xxi]
Circumstantial evidence suggests a link with gynæcomastia[xxii]
but this is open to question.[xxiii] Removal of the breasts may not eliminate the
risk as it has been suggested that the cause of the cancer may be
linked to the hormonal imbalances in KS, causing cells to become cancerous.[xxiv]
In women, a longer than normal menopause can increase the risk
because of fluctuating œstrogen levels,[xxv] and this may have its
equivalent in KS men. Germ cell cancers are those which originate in the
sperm producing cells. Whilst most of
these cells are situated in the testes, a few are in the body cavity
below the lungs where organs such as the liver are situated, called
the mediastinum. In KS there is a very small risk of developing germ cell
cancer originating in the mediastinum, a risk that is greatly reduced
after the age of thirty years. The peak risk group are aged between
15 and 30 years old.[xxvi] Physical impairments
There is a condition,
thought to be common in KS called taurodontism (toro-dont-ism),
which literally means "bull teeth". In
this condition the dental pulp - the living part of the tooth which
contains a nerve, occupies a greater area than normal.
This results in a thinner layer of the hard enamel which
leads to an increased risk of tooth decay.[xxvii] There is another
condition, very rare in KS, called radial ulnar synostosis
in which the radius and ulnar bones in the forearm are fused together. This prevents rotation of the forearm. Emotional and behavioural
aspects
There are a number
of emotional and behavioural problems associated with KS such as
shyness, difficulties in forming relationships, a lack of visible facial
emotion and of motivation. Low
self-esteem may be an issue for adolescents.
Little is yet understood about the reasons for these difficulties;
some may be directly related to the chromosomal abnormality and its
influence on brain development. Others
are secondary to hormonal changes, and their effect on physical development
and maturation.[xxviii] Biology
of male reproductive organs & testosterone
Testosterone (test-os-ter-own) is a
natural chemical which is produced by the body and in males mostly
comes from the testes (singular: testis), the male sex organs. It is what is known as an androgen (and-row-jen),
one of a number of hormones responsible for activating both the growing
male sex organs and at puberty, beard growth and voice deepening,
for example. It is mainly produced in
the testes (95%) by the Leydig cells which are situated around the
seminiferous tubules (see below) in response to the reception of luteinizing
(loot-en-i-zing) hormone (or LH for short) produced by a part of
the brain called the anterior pituitary gland.
Each testis is divided into a series of chambers called
lobules, each of which contains coiled seminiferous tubules. Within these tubules are two types of cell:
the spermatogenic cells which develop into sperm by a process called
spermatogenesis, of which more later; and the Sertoli cells, which
nourish the maturing sperm cells. The
Sertoli cells also perform a number of other functions which include
releasing a hormone called Inhibin, which controls the release from
the Pituitary gland, of Follicle Stimulating Hormone
(or FSH). The seminiferous
tubules are surrounded by blood capillaries and groups of Leydig cells,
which release androgens, or sex hormones, one of which is testosterone. Most of the remaining testosterone is produced
in the adrenal cortex, which is situated on the upper surface of
each kidney. Spermatogenesis is
the name given to the process that occurs in the seminiferous tubules,
which produces sperm. This process
goes on all the time from the onset of puberty, in fertile males. Sperm producing cells upon exposure to testosterone,
divide to produce two "daughter" cells, as they are called (although
this in no way implies any gender).
These "daughter" cells contain the full set of 23 pairs
of chromosomes (total = 46 chromosomes).
One of these "daughter" cells is a new sperm producing cell,
whilst the other cell further divides to form two new cells, each
with only one member of each chromosome pair.
As the unfertilised egg also contains only one member of each
chromosome pair, the act of fertilisation re-institutes an embryo with
46 chromosomes. Now I shall discuss
the male hormone testosterone, which is known as an anabolic steroid
as one of its effects is to promote muscle growth.
It should not be confused with the drugs abused by some athletes
and bodybuilders. Testosterone is
usually given orally (in the form of tablets, by mouth), intramuscular
injections (into the muscle), implantation of pellets or in the form
of a transdermal (ie skin) patch. Testosterone
is given in the form of one or more of its compounds, that is basic
testosterone in a different form which affects how the body deals
with it. These compounds are known as
esters and some are utilised by the body more quickly than others. Testosterone preparations such as Sustanon*
contain a relatively fast acting and a slow acting form, which are
designed so that the drug can begin to work within hours of injection,
lasting from a few days (eg. Testosterone propionate),
to a few weeks (eg. Testosterone enanthate). One of the problems
with testosterone given by mouth is that it has to be given in
relatively high doses to have an effect as the liver, the organ which
removes poisonous substances from the blood, also inactivates
testosterone. Testosterone undecanoate (Restandol*)
is given by tablets. Each tablet
lasts for between 2 to 6 hours normally requiring between 2 and 4
tablets, taken at intervals, a day. It
is more effective if each tablet is taken with food, as this reduces
the amount destroyed by the liver. Men
often find tablet treatment is not strong enough to restore libido.
The implantation of
testosterone pellets is another method, ideally being inserted in the
wall of the abdomen under local anæsthetic.
An implant containing 600mg to 1200mg of testosterone can
last for between 4 and 6 months or more and it has been suggested
that this is the best form (in 1990) in which it can be given.[xxix]
The main problem with implants is their tendency to come out and
need reinsertion. However a
new method of having testosterone became available in the UK in 1996,
called Andropatch*, which as a transdermal patch
delivers testosterone through the skin and one or more patches is
worn every day. Of all these products,
Sustanon is the cheapest, followed by Restandol which is quite expensive whilst the Andropatch appears to be the most expensive of these
three common forms of testosterone. This should not be a problem however
if you use the UK's National Health Service.
The following price comparisons (at 1998 prices[xxx]) should give you an
idea of the relative prices of these three commonly prescribed forms
of testosterone. Andropatch (transdermal) costs £48.00
for either a box of 60 x 2.5mg, or a box of 30 x 5.0mg patches Restandol (tablet) costs £8.69
for 28, or £17.38 for 56 tablets Sustanon (injection) costs £3.67
for 3 x 1ml ampoules of Sustanon 100,
Do
I need testosterone treatment ?
Not necessarily. As mentioned earlier, testosterone offers
the possibility of preventing the development of fatty deposits round
the hips & breast development, where these occur. It can ensure normal development of the penis
if administered under the guidance of a doctor.[xxxi]
In adults it may reduce fatigue etc., prevent osteoporosis[xxxii] and help ensure satisfactory
sexual activity. However it should only
continue to be taken if you and your doctor feel it has benefited
you. The amount of testosterone produced
in the testes by adult KS males varies between individuals. You may find that you may need testosterone
treatment, but it may also offer no real benefit and you may even
experience unwanted side effects (see below).[xxxiii]
The dose needed will vary between individuals and should be
adjusted accordingly. What type of testosterone
form should I ask my doctor for ?
Different forms
(also called esters) of testosterone can have different effects on
different individuals. One form may
suit one person whilst causing problems or having little effect on
another. The type chosen may be influenced
by your preference as to how it should be administered. You may find an injection into your muscle (an intramuscular
injection) more convenient, or you may prefer to have tablets (oral
administration) or a (transdermal) skin patch, for example. Certain combinations of testosterone esters
in a product may prove less satisfactory and even undesirable. What you should be aiming at is a product
that gives a more or less steady level of serum (a component of blood)
testosterone. Possible dangers from
prolonged use of testosterone
Unlike naturally
occurring testosterone, that introduced into the body as a result of
testosterone treatment can cause some long term problems.[xxxiv]
Heart problems, hypertension and the build-up of fluid in the
body (ie: œdema) can occur as a result of salt and water retention by
the body. There may be an increased
risk of atherosclerosis (are-thur-o-scler-o-sis) in which the walls
of the arteries narrow as the result of a build up of fat, which
increases the risk of a stroke. There
is also evidence of polycythemia (poly-sigh-theme-e-a) in which there is
a higher concentration of red blood cells in the blood than normal,
though the evidence suggests the link is with older men.[xxxv]
In some men there is a risk that too high a dose of testosterone
(including in the short term) could result in aggression, psychosis
(sigh-co-sis) and mania[xxxvi]. There is a slight risk that testosterone might
cause problems for someone undergoing anti-coagulant treatment. There may also be a risk of liver damage. Is there a link between KS and criminality
?
The simple answer to
this question is no.
One problem is that KS is sometimes confused with a
different condition known as XYY syndrome. Some early research in the 1960s suggested a link
between the possession of an extra Y chromosome (as in XYY syndrome) and aggression.[xxxvii]
While some research has shown a higher number of XYY men had been
found in high security prisons and special hospitals, other studies
do not support this view. Later research
found little evidence linking XYY syndrome with criminality.[xxxviii]
Whilst early research suggested a link between criminality and
KS, such as that by Nielsen[xxxix]
who found that 38% of KS compared to 6% of XY males committed crimes,
later research has not supported this.[xl] It is also necessary
to remember that KS males are often less mature, passive, impressionable
and more dependent on others, often having few or no friends, and
are therefore more vulnerable to group pressure.[xli] Current thinking accepts
that any association is controversial[xlii]
and more research would be needed before any firm conclusions could
be drawn. References
The KO aims to
produce information sheets containing more information about certain
topics mentioned in this information sheet, such as male breast cancer
and osteoporosis. These information
sheets will be available free to members of the KO. All internet addresses (URLs) given in this document were correct when this document was issued in July 1998. [i] original paper: Klinefelter, H.F. et al: Syndrome
Characterized by Gynecomastia, Aspermatogenesis without A-Leydigism,
& [ii] Bock, R: Understanding Klinefelter's Syndrome: A Guide for XXY males & their families; National Institutes of Health, USA, 1993 (NIH Pub.no: 93-3202) also available at: http://www.iacnet.com/health/15097321.htm [iii] Sørensen, K:
Klinefelter's Syndrome in Childhood, Adolescence
& Youth: A genetic, clinical, developmental, psychiatric & [iv] Ratcliffe, S.G et al: Edinburgh Study of Growth & Development of Children with Sex Chromosome Abnormalities III (in: Children with Sex Chromosome Aneuploidy: Follow-up studies), March of Dimes Birth Defects Foundation: Original Article Series, 1986; 22(3):73-118 (eds. Ratcliffe, S.G & N. Paul) [v] see Sørensen above [vi] see Bock above [vii] Oxford Textbook of Medicine; Sir David Weatherall et al (eds), OUP, 1987 (2nd edition) [viii] see Sørensen above [ix] Ratcliffe, S.G et al: Edinburgh Study of Growth & Development of Children with Sex Chromosome Abnormalities IV (in: Children & Young Adults with Sex Chromosome Aneuploidy: Follow-up Clinical & Molecular studies), March of Dimes Birth Defects Foundation: Original Article Series, 1991; 26(4):1-44 (eds. Evans, J.A et al) [x] personal communication with Professor M.A.Ferguson-Smith [xi] information supplied by Professor David Skuse [xii] see Weatherall above [xiii] Martinus, J: Psychiatric Aspects of Klinefelter's Syndrome in Adolescence; from Klinefelter's Syndrome eds. Bandmann, H.-J & R.Breit, Springer, 1984 [xiv] Luisetto G. et al: Bone
mass and mineral metabolism in Klinefelter's syndrome; Osteoporos
Int 1995;5(6):455-461 [xv] Kubler A. et al: The influence
of testosterone substitution on bone mineral density in patients
with Klinefelter's syndrome; [xvi] This is
supported by research by Wong, F.H. et al: Loss of bone mass in
patients with Klinefelter's syndrome despite sufficient [xvii] Osteosal™ is used with the electronic reader InstaQuant™ developed by Cortecs Diagnostics Limited, who can be contacted either by E-mail at: [email protected] or by post at: Newtech Square, Deeside Industrial Park, Deeside, CH5 2NT, United Kingdom. [xviii] Sasco,
Annie J. et al: Review article: Epidemiology of male
breast cancer. A meta-analysis of published case-controlled studies
& [xix] research by Hultborn et al in 1997 suggests the risk of male breast cancer in KS males may be as high as 7.5%, though it has been acknowledged that methodological differences may account for that figure. see: Hultborn, R. et al: Prevalence of Klinefelter's syndrome in male breast cancer patients; Anticancer Res, Vol 17, Nov.1997: 4293-4297 [xx] Whitehouse, David & Maurice Slevin: Cancer: the facts; OUP, 1996 (2nd edition) [xxi] Scheike,
O et al: Male breast cancer; Acta Pathol Microbiol
Scand, 1975 Suppl 251: 3-35 found an average age of 65.2 years
out of 257 cases, whereas Hultborn et al (see reference above)
found the average age to be 72 out of 93 cases [xxii] see Scheike above [xxiii] van Geel, A.N et al: A retrospective study of male breast cancer in Holland; Br J Surgery, 1985 Sept; 72(9): 724-727 [xxiv] Thomas, David B: Breast cancer in men; Epidemiological Reviews, 1993 (15) no.1: 220-231; for more information on male breast cancer see: http://interact.withus.com/interact/mbc/index.html; see also: Volm, M.D. et al: Pituitary adenoma and bilateral male breast cancer: an unusual association; J.Surg.Oncol: Jan.1997, 64(1): 74-78 [xxv] see Whitehouse above [xxvi] � Hasle, H et al: Cancer incidence in men with Klinefelter syndrome; Br.J.Cancer 1995 Feb; 71(2): 416-420; ‚ Hasle, H et al: Mediastinal germ cell tumour associated with Klinefelter syndrome. A report of case and review of the literature; Eur.J.Pediatr. 1992 Oct; 151(10): 735-739; ƒ Nichols, C.R et al: Klinefelter's syndrome associated with mediastinal germ cell neoplasms; J. Clinical Oncology 1987; 5(8): 1290-1294; For more information on germ cell tumours generally, see: http://www.mc.vanderbilt.edu/peds/pidl/hemeonc/germcell.html note:
Approximately 20% of non-seminomatous malignant germ
cell tumours are associated with Klinefelter's syndrome (47,XXY).
At least 8% of primary mediastinal germ cell tumours are in men
with KS. [xxvii] Paulsen, C.Alvin & S.R.Plymate: Klinefelter's syndrome; from The Genetic Basis of Common Diseases, eds. King, et al (Oxford Monographs on Medical Genetics, 1992) chapter 44 [xxviii] see Skuse above [xxix] Handelsmann, David J: Pharmacology of testosterone pellet implants; in 'Testosterone: action, deficiency, substitution' eds. E. Nieschlag & H.M.Behre, Springer, 1990 [xxx] MIMS, June 1998: 190-193 [xxxi] see Ferguson-Smith above [xxxii] Aspray, T.J. et al: Consequences of withholding testosterone treatment; Lancet, 1996 (348): 609 [xxxiii] see Ferguson-Smith above [xxxiv] Gooren, Louis J.G. & Kaas H. Polderman: Safety aspects of androgen therapy; in 'Testosterone: action, deficiency, substitution' eds. E. Nieschlag & H.M.Behre, Springer, 1990 [xxxv] Hajjar, R.R. et al: Outcomes of long-term testosterone replacement in older hypogonadal males: a retrospective analysis; J.Clin.Endocrinol.Metab, Vol 82, Nov.1997: 3793-3796; Drinka, P.J. et al: Polycythemia as a complication of testosterone replacement therapy in nursing home men with low testosterone levels; J.Am.Geriatr.Soc, Vol 43, Aug.1995: 899-901 [xxxvi] there may be an association between KS and bipolar disorder: see: Everman, D.B. & Stoudemire, A: Bipolar disorder associated with Klinefelter's syndrome and other chromosomal abnormalities; Psychosomatics, Vol 35, Jan.1994: 35-40; Bekaroglu, M. et al: Bipolar affective disorder associated with Klinefelter's syndrome - a case report; Isr.J.Psychiatry Relat.Sci., Vol 34(4) 1997: 308-310 [xxxvii] Wilson, J.Q. & Herrnstein, R.J: Crime and Human Nature; Touchstone, 1986 [xxxviii] Owen, R.D: The
47,XYY male: a review; Psychological Bulletin, Vol 78, 1972:
209-233; Thielgaard, R:
Aggression and XYY [xxxix] Nielsen, Johannes
et al: A Psychiatric-Psychological Study of 50 Severely
Hypogonadal Male Patients, Including 34 with [xl] Forssman, H. et al: Children with supernumary X-chromosome. A ten-year follow-up study of schoolchildren in special classes; J.Ment.Defic.Res, Vol 23, Sept.1979: 189-193; Nielsen, Johannes & Pelsen, B: Follow-up 20 years later of 34 Klinefelter males with karyotype 47,XXY and 16 hypogonadal males with karyotype 46,XY; Hum.Genet, Vol 77, Oct.1987: 188-192 [xlii] personal correspondence with Professor P.A.Jacobs GENERAL REFERENCES Concise Medical Dictionary (Oxford Reference) (4th edition) OUP, 1994 Human Anatomy and Physiology by: Carola, Harley & Noback: (2nd edition) McGraw-Hill, 1992 Nielsen, J: Klinefelter's syndrome: an orientation; Gallo Tryk, Denmark, 1991 (2nd edition); latest edition available through Turner Centre's internet site at: http://www.aaa.dk/turner/tfsen.htm or free for KS men or the parents of KS boys, via E-mail at: [email protected] or by writing to: Turner Centeret, Skovagervej 2, DK-8240 Risskov, Denmark. (tel: +45 86 17 77 77 ext 3684 - Danish time = GMT +1 hour)
Information sheet: by Steve R Hammett
for the KO © 1998, 2000. A single photocopy may be made for private
use, without prior permission. This document may be quoted from, so
long as attribution is given to the author, above. Doctors & other professionals helping people with Klinefelter's syndrome may make copies for their patients & medical students, etc. Klinefelter Organisation (formerly
the Klinefelter's Syndrome Club UK - KSCUK) is
a national voluntary organisation
which relies on private donations and members' subscriptions. We are a self-help group. For more information contact the KO The KO has its
own internet site at: http://www.klinefelter.org.uk We can be contacted
by E-mail at: [email protected] Postal
address: PO Box
223, Bolton, BL1 8PS
For postal
enquiries within the UK an SAE would be appreciated. This document has been
checked by those members of our team of honorary professional
advisers marked with a star (¯), who are:- Professor M. A. Ferguson-Smith
MB, ChB, FRCPath, FRCP, FRSE, FRS (Genetics) ¯ Professor P. A. Jacobs DSc,
FRCPath, FRS (Genetics) ¯ Professor A. J. Green MB,
PhD, FRCPI (Genetics) ¯ Professor D. H. Skuse MD,
FRCP, FRCPsych, FRCPCH (Pædiatric Psychiatry) ¯ Professor M. D. Kopelman PhD,
FBPsS, FRCPsych (Psychiatry) ¯ Dr F. C. W. Wu BSc,
MD, FRCP, FRCPE(Endocrinology) Dr A. J. Chapman MD,
FRCP (Endocrinology) Dr G. Butler MD,
FRCPCH, FRCP (Pædiatric & Adolescent Endocrinology) ¯ Dr S. K. R. Johnson MA,
MB, BChir, MRCGP, DRCOG, DCHGP (General Practitioner) The KO is a member of the Genetic Interest Group (UK) and is involved with European Patients' Voice (EU) |
