XYY syndrome, also known as Jacobs syndrome, is an

aneuploid Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any ...

genetic condition in which a male has an extra

Y chromosome The Y chromosome is one of two sex chromosomes (allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or abse ...

. There are usually few symptoms. These may include being taller than average,

acne Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...

, and an increased risk of

learning disabilities Learning disability, learning disorder, or learning difficulty (British English) is a condition in the brain that causes difficulties comprehending or processing information and can be caused by several different factors. Given the "difficult ...

. The person is generally otherwise normal, including typical rates of

fertility Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertili ...

. The condition is generally not inherited from a person's parents but rather occurs as a result of a random event during sperm development. Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime. There are 47 chromosomes, instead of the usual 46, giving a 47,XYY karyotype. Treatment may include speech therapy or extra help with schoolwork, but outcomes are generally good. The condition occurs in about 1 in 1,000 male births. Many people with the condition are unaware that they have it. The condition was first described in 1961.

Signs and symptoms

Physical traits

People with the 47,XYY karyotype have an increased growth rate from early childhood, with an average final height approximately 7 cm (3") above expected final height. In

Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian on the southern shore of t ...

Scotland Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...

, eight 47,XYY boys born 1967–1972 and identified in a newborn screening programme had an average height of 188.1 cm (6'2") at age 18—their fathers' average height was 174.1 cm (5'8"), their mothers' average height was 162.8 cm (5'4"). The increased gene dosage of three X/Y chromosome

pseudoautosomal region The pseudoautosomal regions, PAR1, PAR2, are homologous sequences of nucleotides on the X and Y chromosomes. The pseudoautosomal regions get their name because any genes within them (so far at least 29 have been found for humans) are inherited ...

(PAR1)

SHOX The short-stature homeobox gene (SHOX), also known as short-stature-homeobox-containing gene, is a gene located on both the X and Y chromosomes, which is associated with short stature in humans if mutated or present in only one copy ( haploinsuff ...

genes has been postulated as a cause of the increased stature seen in all three sex chromosome trisomies: 47,XXX, 47,XXY, and 47,XYY. p. 2304: Table 561-1. Differential diagnosis of tall stature and overgrowth syndromes. Postnatal overgrowth leading to childhood tall stature—includes: Klinefelter syndrome (XXY), SHOX excess syndromes, XYY. * * * Severe

was noted in a very few early case reports, but dermatologists specializing in acne now doubt the existence of a relationship with 47,XYY. Prenatal

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

levels are normal in 47,XYY males. Most 47,XYY males have normal sexual development and have normal fertility.

Cognitive and behavioral traits

In contrast to the other common sex chromosome

aneuploidies Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any ...

— 47,XXX and 47,XXY (

Klinefelter syndrome Klinefelter syndrome (KS), also known as 47,XXY, is an aneuploid genetic condition where a male has an additional copy of the X chromosome. The primary features are infertility and small, poorly functioning testicles. Usually, symptoms are sub ...

)—the average IQ scores of 47,XYY boys identified by newborn screening programs were not reduced compared to the general population. In a summary of six prospective studies of 47,XYY boys identified by newborn screening programmes, twenty-eight 47,XYY boys had an average 100.76 verbal IQ, 108.79 performance IQ, and 105.00 full-scale IQ. In a systematic review including two prospective studies of 47,XYY boys identified by newborn screening programs and one retrospective study of 47,XYY men identified by screening men over 184 cm (6'") in height, forty-two 47,XYY boys and men had an average 99.5 verbal IQ and 106.4 performance IQ. In prospective studies of 47,XYY boys identified by newborn screening programs, the IQ scores of 47,XYY boys were usually slightly lower than those of their siblings. In Edinburgh, fifteen 47,XYY boys with siblings identified in a newborn screening program had an average 104.0 verbal IQ and 106.7 performance IQ, while their siblings had an average 112.9 verbal IQ and 114.6 performance IQ. Approximately half of 47,XYY boys identified by newborn screening programs had learning difficulties—a higher proportion than found among siblings and above-average-IQ control groups. In Edinburgh, 54% of 47,XYY boys (7 of 13) identified in a newborn screening program received remedial reading teaching compared to 18% (4 of 22) in an above-average-IQ control group of 46,XY boys matched by their father's social class. In

Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...

, USA 55% of 47,XYY boys (6 of 11) identified in a newborn screening program had learning difficulties and received part-time resource room help compared to 11% (1 of 9) in an above-average-IQ control group of 46,XY boys with familial balanced autosomal chromosome translocations. Developmental delays and behavioral problems are also possible, but these characteristics vary widely among affected boys and men, are not unique to 47,XYY and are managed no differently from in 46,XY males. Aggression is not seen more frequently in 47,XYY males. Patients with Jacobs syndrome have been shown to have a higher risk of developing certain diseases such as

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...

, seizure problems, and tremors. Some 47,XYY patients have been found to have genitourinary malformations. These include cryptorchidism, hypoplastic scrotum, microphallus, and hypospadias. These men could be diagnosed with infertility as a result of oligospermia or sperm chromosomal abnormalities. According to certain psychological studies, these patients may probably have problems with impulse control and emotional regulation. Increased testosterone levels were found to be correlated with an increased risk of aggressive behavior in incarcerated males with 47,XYY syndrome.

47,XYY is not inherited, but usually occurs as a random event during the formation of sperm cells. An incident in chromosome separation during anaphase II (of

meiosis II Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately res ...

) called

nondisjunction Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division (mitosis/meiosis). There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis ...

can result in sperm cells with an extra copy of the Y-chromosome. If one of these atypical sperm cells contributes to the genetic makeup of a child, the child will have an extra Y-chromosome in each of the body's cells. In some cases, the addition of an extra Y-chromosome results from nondisjunction during cell division during a post-zygotic mitosis in early embryonic development. This can produce 46,XY/47,XYY mosaics.

Diagnosis

47,XYY syndrome is not usually diagnosed until learning issues are present. The syndrome is diagnosed in an increasing number of children prenatally by

amniocentesis Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is n ...

and chorionic villus sampling in order to obtain a chromosome karyotype, where the abnormality can be observed. It is estimated that only 15–20% of children with 47,XYY syndrome are ever diagnosed. Of these, approximately 30% are diagnosed prenatally. For the rest of those diagnosed after birth, around half are diagnosed during childhood or adolescence after developmental delays are observed. The rest are diagnosed after any of a variety of symptoms, including fertility problems (5%) have been seen.

Epidemiology

Around 1 in 1,000 boys are born with a 47,XYY karyotype. The incidence of 47,XYY is not known to be affected by the parents' ages.

History

1960s

In April 1956, '' Hereditas'' published the discovery by cytogeneticists

Joe Hin Tjio Joe Hin Tjio (2 November 1919 – 27 November 2001), was an Indonesian-born American cytogeneticist. He was renowned as the first person to recognize the normal number of human chromosomes on December 22, 1955 at the Institute of Genetics of the ...

and

Albert Levan Albert Levan (8 March 1905 – 28 March 1998) was a Swedish botanist and geneticist. Albert Levan is best known today for co-authoring the report in 1956 that humans had forty-six chromosomes (instead of forty-eight, as previously believed). Thi ...

Lund University , motto = Ad utrumque , mottoeng = Prepared for both , established = , type = Public research university , budget = SEK 9 billion Sweden that the normal number of chromosomes in diploid human cells was 46—not 48 as had been believed for the preceding thirty years. In the wake of the establishment of the normal number of human chromosomes, 47,XYY was the last of the common sex chromosome aneuploidies to be discovered, two years after the discoveries of 47,XXY,

45,X Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairl ...

, and 47,XXX in 1959. Even the much less common

48,XXYY XXYY syndrome is a sex chromosome anomaly in which males have 2 extra chromosomes, one X and one Y chromosome. Human cells usually contain two sex chromosomes, one from the mother and one from the father. Usually, females have two X chromosomes ( ...

had been discovered in 1960, a year before 47,XYY. Screening for those

X chromosome The X chromosome is one of the two sex-determining chromosomes (allosomes) in many organisms, including mammals (the other is the Y chromosome), and is found in both males and females. It is a part of the XY sex-determination system and XO sex ...

aneuploidies was possible by noting the presence or absence of "female" sex chromatin bodies ( Barr bodies) in the nuclei of

interphase Interphase is the portion of the cell cycle that is not accompanied by visible changes under the microscope, and includes the G1, S and G2 phases. During interphase, the cell grows (G1), replicates its DNA (S) and prepares for mitosis (G2). A c ...

cells in buccal smears, a technique developed a decade ''before'' the first reported sex chromosome aneuploidy. An analogous technique to screen for Y-chromosome aneuploidies by noting supernumerary "male" sex chromatin bodies was not developed until 1970, a decade ''after'' the first reported sex chromosome aneuploidy. * The first published report of a man with a 47,XYY karyotype was by internist and cytogeneticist Avery Sandberg and colleagues at

Roswell Park Comprehensive Cancer Center Roswell Park Comprehensive Cancer Center is a cancer research and treatment center located in Buffalo, New York. Founded by surgeon Roswell Park in 1898, the center was the first in the United States to specifically focus on cancer research. The ...

(then known as Roswell Park Memorial Institute) in

Buffalo, New York Buffalo is the second-largest city in the U.S. state of New York (behind only New York City) and the seat of Erie County. It is at the eastern end of Lake Erie, at the head of the Niagara River, and is across the Canadian border from Sou ...

in 1961. It was an incidental finding in a normal 44-year-old, 6 ft. 83 cmtall man of average intelligence who was karyotyped because he had a daughter with

Down syndrome Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual dis ...

. * Only a dozen isolated 47,XYY cases were reported in the medical literature in the four years following the first report by Sandberg. Then, in December 1965 and March 1966, ''

Nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...

'' and ''

The Lancet ''The Lancet'' is a weekly peer-reviewed general medical journal and one of the oldest of its kind. It is also the world's highest-impact academic journal. It was founded in England in 1823. The journal publishes original research articles, ...

'' published the first preliminary reports by British cytogeneticist Patricia Jacobs and colleagues at the MRC Human Genetics Unit at

Western General Hospital The Western General Hospital (often abbreviated to simply ‘The Western General’) is a health facility at Craigleith, Edinburgh, Scotland. It is managed by NHS Lothian. History The hospital was designed by Peddie and Kinnear and opened as ...

of a chromosome survey of 315 male patients at State Hospital in

Carstairs Carstairs (, Scottish Gaelic: ''Caisteal Tarrais'') is a village in South Lanarkshire, Scotland. Carstairs is located east of the county town of Lanark and the West Coast Main Line runs through the village. The village is served by Carstairs r ...

Lanarkshire Lanarkshire, also called the County of Lanark ( gd, Siorrachd Lannraig; sco, Lanrikshire), is a historic county, lieutenancy area and registration county in the central Lowlands of Scotland. Lanarkshire is the most populous county in Scotl ...

—

's only special security hospital for

developmentally disabled Developmental disability is a diverse group of chronic conditions, comprising mental or physical impairments that arise before adulthood. Developmental disabilities cause individuals living with them many difficulties in certain areas of life, espe ...

people —that found nine patients, ages 17 to 36, averaging almost 6 ft. in height (avg. 5'11", range: 5'7" to 6'2"), had a 47,XYY karyotype, and mischaracterized them as aggressive and violent criminals. Over the next decade, almost all published XYY studies were on height-selected, institutionalized XYY males. In January 1968 and March 1968, ''

'' and ''

Science Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earli ...

'' published the first U.S. reports of tall, institutionalized XYY males by Mary Telfer, a biochemist, and colleagues at the Elwyn Institute. * Telfer found five tall, developmentally disabled XYY boys and men in hospitals and penal institutions in

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, and since four of the five had at least moderate facial

, reached the erroneous conclusion that acne was a defining characteristic of XYY males. After learning that convicted mass murderer

Richard Speck Richard Benjamin Speck (December 6, 1941 – December 5, 1991) was an American mass murderer who killed eight student nurses in their South Deering, Chicago, residence via stabbing, strangling, slashing their throats, or a combination of the th ...

had been karyotyped, Telfer not only incorrectly assumed the acne-scarred Speck was XYY, but reached the false conclusion that Speck was the

archetypical The concept of an archetype (; ) appears in areas relating to behavior, historical psychology, and literary analysis. An archetype can be any of the following: # a statement, pattern of behavior, prototype, "first" form, or a main model that ot ...

XYY male—or "supermale" as Telfer referred to XYY males outside of peer-reviewed scientific journals. In April 1968, ''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid d ...

''—using Telfer as a main source—introduced the XYY genetic condition to the general public in a three-part series on consecutive days that began with a Sunday front-page story about the planned use of the condition as a mitigating factor in two murder trials in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), ma ...

Daniel Hugon, Paris, France * * and

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

Lawrence Hannell, Melbourne, Australia * * * An Australian murder case that was reported to have been decided on the basis of the so-called XYY syndrome actually was not concerned with chromosome counts at all.—and falsely reported that Richard Speck was an XYY male and that the condition would be used in an appeal of his murder conviction. * * * * * * —article by

Vanderbilt University Vanderbilt University (informally Vandy or VU) is a private research university in Nashville, Tennessee. Founded in 1873, it was named in honor of shipping and rail magnate Cornelius Vanderbilt, who provided the school its initial $1-million ...

endocrinologist and geneticist Eric Engel, who performed two confidential chromosome analyses of Speck in September 1966 and June 1968. Based on mischaracterizations of XYY males as aggressive and violent criminals in the December 1965 and March 1966 preliminary reports by Jacobs, et al., Engel had made an unsolicited request in August 1966 to Speck's appointed defense attorney,

Cook County Public Defender The Cook County Public Defender provides legal representation for indigent clients in the areas of felony and misdemeanor criminal cases, delinquency, abuse/neglect, some appeals, post-conviction and traffic (non-petty) cases when appointed by the ...

Gerald W. Getty, to confidentially karyotype Speck—which was repeated after false news reports in April 1968 that Speck was XYY. The series was echoed the following week by articles—again using Telfer as a main source—in ''

Time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, ...

'' and ''

Newsweek ''Newsweek'' is an American weekly online news magazine co-owned 50 percent each by Dev Pragad, its president and CEO, and Johnathan Davis, who has no operational role at ''Newsweek''. Founded as a weekly print magazine in 1933, it was widely ...

'', and six months later in ''

The New York Times Magazine ''The New York Times Magazine'' is an American Sunday magazine supplement included with the Sunday edition of ''The New York Times''. It features articles longer than those typically in the newspaper and has attracted many notable contributors. ...

''. In December 1968, the ''

Journal of Medical Genetics The ''Journal of Medical Genetics'' is a monthly peer-reviewed medical journal covering all aspects of medical genetics, including reviews of and opinion on the latest developments. It was established in 1964 and is published by the BMJ Group. The ...

'' published the first XYY review article—by Michael Court Brown, director of the MRC Human Genetics Unit—which reported no overrepresentation of XYY males in nationwide chromosome surveys of prisons and hospitals for developmentally disabled and mentally ill people in Scotland, and concluded that studies confined to institutionalized XYY males may be guilty of selection bias, and that long-term

longitudinal Longitudinal is a geometric term of location which may refer to: * Longitude ** Line of longitude, also called a meridian * Longitudinal engine, an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicl ...

prospective studies of newborn XYY boys were needed. In May 1969, at the annual meeting of the

American Psychiatric Association The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 37,000 members are involv ...

, Telfer and her Elwyn Institute colleagues reported that case studies of the institutionalized XYY and XXY males they had found convinced them that XYY males had been falsely stigmatized and that their behavior may not be significantly different from chromosomally normal 46,XY males. In June 1969, the

National Institute of Mental Health The National Institute of Mental Health (NIMH) is one of 27 institutes and centers that make up the National Institutes of Health (NIH). The NIH, in turn, is an agency of the United States Department of Health and Human Services and is the prima ...

(NIMH) Center for Studies of Crime and Delinquency held a two-day XYY conference in Chevy Chase, Maryland. In December 1969, with a grant from the NIMH Center for Studies of Crime and Delinquency, cytogeneticist Digamber Borgaonkar at

Johns Hopkins Hospital The Johns Hopkins Hospital (JHH) is the teaching hospital and biomedical research facility of the Johns Hopkins School of Medicine, located in Baltimore, Maryland, U.S. It was founded in 1889 using money from a bequest of over $7 million (1873 m ...

began a chromosome survey of (predominantly African-American) boys ages 8 to 18 in all

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

institutions for delinquent, neglected, or mentally ill juveniles, which was suspended from February–May 1970 due to an

American Civil Liberties Union The American Civil Liberties Union (ACLU) is a nonprofit organization founded in 1920 "to defend and preserve the individual rights and liberties guaranteed to every person in this country by the Constitution and laws of the United States". T ...

(ACLU) lawsuit about the lack of informed consent. Concurrently, through 1974, psychologist

John Money John William Money (8 July 1921 – 7 July 2006) was a New Zealand psychologist, sexologist and author known for his research into sexual identity and Sex determination and differentiation (human), biology of gender. He was one of the first ...

at Johns Hopkins Hospital experimented on thirteen XYY boys and men (ages 15 to 37) in an unsuccessful attempt to treat their history of behavior problems by

chemical castration Chemical castration is castration via anaphrodisiac drugs, whether to reduce libido and sexual activity, to treat cancer, or otherwise. Unlike surgical castration, where the gonads are removed through an incision in the body,

using high-dose

Depo-Provera Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in injectable form and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. It is used as a method of bi ...

—with side-effects of weight gain (avg. 26 lbs.) and suicide. In the late 1960s and early 1970s, screening of consecutive newborns for sex chromosome abnormalities was undertaken at seven centers worldwide: in Denver (Jan 1964–1974),

(Apr 1967–Jun 1979), New Haven (Oct 1967–Sep 1968), Toronto (Oct 1967–Sep 1971), Aarhus (Oct 1969–Jan 1974, Oct 1980–Jan 1989), Winnipeg (Feb 1970–Sep 1973), and

(Apr 1970–Nov 1974). * * * The Boston study, led by Harvard Medical School child psychiatrist Stanley Walzer at Children's Hospital Boston, Children's Hospital, was unique among the seven newborn screening studies in that it only screened newborn ''boys'' (non-private-ward newborn boys at the Brigham and Women's Hospital, Boston Hospital for Women) and was funded in part by grants from the NIMH Center for Studies of Crime and Delinquency. * * * * * * * * * * * * * The Edinburgh study was led by Shirley Ratcliffe who focused her career on it and published the results in 1999.

1970s

In December 1969, Lore Zech at the Karolinska Institutet, Karolinska Institute in Stockholm first reported intense fluorescence of the Adenine, A Thymine, T-rich distal half of the long arm of the Y chromosome in the nuclei of metaphase cells treated with quinacrine mustard. In April 1970, Peter Pearson and Martin Bobrow at the Medical Research Council (UK), MRC Population Genetics Unit in Oxford and Canino Vosa at the University of Oxford reported fluorescent "male" sex chromatin bodies in the nuclei of interphase cells in buccal smears treated with quinacrine dihydrochloride, which could be used to screen for Y chromosome aneuploidies like 47,XYY. * In June 1970, ''The XYY Man'' was published—the first of seven Kenneth Royce spy novels whose fictional tall, intelligent, nonviolent XYY hero was a reformed expert cat burglar recruited by British intelligence for dangerous assignments—and later adapted into a thirteen-episode British summer television series broadcast in 1976 and 1977. In other fictional television works, a January 1971 episode "By the Pricking of My Thumbs ..." of the British science fiction TV series ''Doomwatch'' featured an XYY boy expelled from school because his genetic condition led him to be falsely accused of nearly blinding another boy, By the Pricking of My Thumbs ... written by Robin Chapman. Sixteen-year-old Stephen Franklin is expelled from school because, his father says, he has an obscure genetic defect—an extra "Y" chromosome. a November 1993 episode "Born Bad" of the American police procedural TV series ''Law & Order'' portrayed a 14-year-old XYY sociopathic murderer, One of TV's most consistently rewarding series takes a grim and unforgettable detour into the bleak mindset of a teen-age sociopathic murderer. Is society to blame, or as his lawyer argues, is he genetically predisposed to violence, with an extra "Y" chromosome? … the boy's hopeless future seems all too evident. and the May 2007 season finale episode "Born To Kill" of the American police procedural TV series ''CSI: Miami'' depicted a 34-year-old XYY serial killer. There's nothing funny about the season finale. That episode is about a serial killer with "criminal" genes. "It's a real-life natural-born killer situation", executive producer Ann Donahue says. "Usually girls have XX chromosomes and boys have XY, but this killer is XYY, which means too much testosterone." Among other niceties, the killer who has ties to Boston… brands his female victims with the letter Y. The false stereotype of XYY boys and men as violent criminals has also been used as a plot device in the horror films ''Il gatto a nove code'' in February 1971 (dubbed into English as ''The Cat o' Nine Tails'' in May 1971) and ''Alien 3'' in May 1992. In December 1970, at the annual meeting of the American Association for the Advancement of Science (AAAS), its retiring president, geneticist H. Bentley Glass, cheered by the legalization of abortion in New York (state), New York, envisioned a future where pregnant women would be required by the government to abort XYY "sex deviants". Mischaracterization of the XYY genetic condition was quickly incorporated into high school biology textbooks and medical school psychiatry textbooks, * where misinformation still persists decades later. In 1973, child psychiatrist Herbert Schreier at Children's Hospital told Harvard Medical School microbiologist Jon Beckwith of Science for the People that he thought Walzer's Boston XYY study was unethical; Science for the People investigated the study and filed a complaint with Harvard Medical School about the study in March 1974. In November 1974, Science for the People went public with their objections to the Boston XYY study in a press conference and a ''New Scientist'' article alleging inadequate informed consent, a lack of benefit (since no specific treatment was available) but substantial risk (by stigmatization with a false stereotype) to the subjects, and that the unblinded experimental design could not produce meaningful results regarding the subjects' behavior. In December 1974, the Harvard Standing Committee on Medical Research issued a report supporting the Boston XYY study and in March 1975, the faculty voted 199–35 to allow continuation of the study. After April 1975, screening of newborns was discontinued—changes to informed consent procedures and pressure from additional advocacy groups, including the Children's Defense Fund, having led to the discontinuation of the last active U.S. newborn screening programs for sex chromosome abnormalities in Boston and Denver. In August 1976, ''Science'' published a retrospective cohort study by Educational Testing Service psychologist Herman Witkin and colleagues that screened the tallest 16% of men (over 184 cm (6'0") in height) born in Copenhagen from 1944 to 1947 for XXY and XYY karyotypes, and found an increased rate of minor criminal convictions for property crimes among sixteen XXY and twelve XYY men may be related to the lower intelligence of those with criminal convictions, but found no evidence that XXY or XYY men were inclined to be aggressive or violent. * * * *

1980s and later

The March of Dimes sponsored five international conferences in June 1974, November 1977, May 1981, June 1984, and June 1989 and published articles from the conferences in book form in 1979, 1982, 1986, and 1991 from seven longitudinal prospective cohort study, prospective cohort studies on the development of over 300 children and young adults with sex chromosome abnormalities identified in the screening of almost 200,000 consecutive births in hospitals in Denver, Edinburgh, New Haven, Toronto, Aarhus, Winnipeg, and Boston from 1964 to 1975. These seven studies—the only unbiased studies of unselected individuals with sex chromosome abnormalities—have replaced the older, biased studies of institutionalized individuals in understanding the development of individuals with sex chromosome abnormalities.The last active longitudinal prospective study ended in 2000 with the end of the 36-year Denver study following the death of pediatrician and geneticist Arthur Robinson. * * In May 1997, ''Nature Genetics'' published the discovery by Ercole Rao and colleagues of the X/Y chromosome

(PAR1)

gene, haploinsufficiency of which leads to short stature in Turner syndrome (45,X). It was subsequently postulated that the increased gene dosage of three SHOX genes leads to tall stature in the sex chromosome trisomies 47,XXX, 47,XXY, and 47,XYY. In July 1999, ''Psychological Medicine'' published a case-control study by Royal Edinburgh Hospital psychiatrist Michael Götz and colleagues that found an increased rate of criminal convictions among seventeen XYY men identified in the Edinburgh newborn screening study compared to an above-average-IQ control group of sixty XY men, which multiple logistic regression analysis indicated was mediated mainly through lowered intelligence. In June 2002, the ''American Journal of Medical Genetics'' published results from a longitudinal prospective cohort Denver Family Development Study led by pediatrician and geneticist Arthur Robinson, which found that in fourteen prenatal diagnosis, prenatally diagnosed 47,XYY boys (from high socioeconomic status families), IQ scores available for six boys ranged from 100 to 147 with a mean of 120. For the eleven of fourteen boys with siblings, in nine instances their siblings were stronger academically, but in one case the subject was performing equal to, and in another case superior to, his siblings.

Society and culture

Some medical geneticists question whether the term "syndrome" is appropriate for this condition because many people with this karyotype appear normal.

References

External links

* Nielsen, Johannes (1998)
XYY males. An orientation
{{DEFAULTSORT:Xyy Syndrome Syndromes Sex chromosome aneuploidies Wikipedia medicine articles ready to translate Rare syndromes

Signs and symptoms

Physical traits

Cognitive and behavioral traits

Diagnosis

Epidemiology

History

1960s

1970s

1980s and later

Society and culture

See also

References

External links