Can males have double Y chromosomes?
372234
Taken from Wikipedia (see link below)...\n\nXYY syndrome is also called Jacob's Syndrome, XYY-trisomy, 47,XYY aneuploidy, or Supermale syndrome.\n\nFirst case\nThe first published report of a man with a 47,XYY chromosome constitution was by Dr. Avery A. Sandberg, et al. in 1961. It was an incidental finding in a normal 44-year-old, 6 ft. [183 cm] tall man of average intelligence.\n\nPhysical traits\nXYY syndrome typically causes no unusual physical features or medical problems. Males with this syndrome may be slightly taller than average and are typically a few centimeters taller than their father and siblings.\n\nSkeletal malformations may also accompany XYY syndrome at a higher rate than in the general population. Severe facial acne has occasionally been reported, but dermatologists specializing in acne (Plewig & Kligman, 2000) now doubt the existence of a relationship with XYY. Several other physical characteristics, including large hands and feet, have been associated (although not definitively) with XYY syndrome. Any physical characteristics, however, are usually so slight that they are insufficient evidence to suggest a diagnosis.\n\nMost males with XYY syndrome have normal sexual development and are able to conceive children.\n\nSince there are no distinct physical characteristics, the condition usually is only detected during genetic analysis for other reasons.\n\nBehavioral characteristics\nXYY boys have an increased risk of minor speech and motor skill delays and learning disabilities with roughly half requiring some special education intervention. Behavior problems are common, but are not unique to XYY boys and are managed no differently than in XY boys. There have been suggestions of elevated frequency of XYY genotype in inmates and delinquents. A common myth is that the Y Chromosome (male sex chromosome) adds to the aggression and antisocial behavior of people who have this syndrome. No clear evidence exists of it leading to aggression. However, scientists have noticed that an abnormal amount of prison inmates in comparrison to the general population have the XYY chromosome (still some think this is no proof of a link).\n\nCause and prevalence\nXYY syndrome is not inherited, but usually occurs as a random event during the formation of sperm cells. An error in cell division called nondisjunction can result in sperm cells with an extra copy of the Y chromosome. If one of these atypical reproductive 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 occurs as an accident during cell division in early fetal development.\n\nThe incidence of this condition is approximately one in 850 males.\n\n\nThe 48, XXYY (male) syndrome occurs 1 in 17,000 births and is also considered to be a variation of Klinefelter's syndrome. There have been limited studies on XXYY, but people who have XXYY are mostly normal.
679731
Yes.  This does happen to both males and females.
617160
Chromosomal abnormalities, and missing or extra chromosomes.\n\nAlso sex: there are some XY people who appear to be female.
760482
Yes, you can. My brother has 1 testis and he has 2 children a boy and a girl. Good luck.
917555
It's not a mutation, per se, because it doesn't involve a change in the DNA, just a malfunction in the production of germ cells.  What disease it is depends on which chromosome you're talking about.\n\n- Down Syndrome is an extra copy of chromosome 21.  This is the most frequent extra chromosome aberration in the population.\n- Edward's Syndrome is an extra copy of chromosome 18.  This is the second most frequent.\n- Patau Syndrome is an extra copy of chromosome 13.\n- Klinefelter's Syndrome occurs in men with two X chromosomes and one Y.\n- XYY Syndrome is (obviously) a man with an extra Y.\n- XXX Syndrome is a woman with an extra X.  (And has nothing to do with Vin Diesel).\n\nI'm sure there are more, but they start to become really, really rare.  I'd provide links for all those diseases, but there's so many of them!  Hope that helps!
148814
No. Don't confuse the common phrase that "we all start as female" with the individual set of chromosomes. XY embryos are male; the "activation", so to speak, of the factors that will lead that individual to have male characteristics (gonads, genitalia and secondary sexual characters) occurs some time after the start of embryonic development. Thus if one examines an earlier embryo, males are indistinguishable from females.\nBut they each have their XX (females) or XY (males) sexual chromosome pair, and the proteins coded in their genome will lead to normal development of either sex.
260970
Yes, it is XYY and it is uncommon.  However, if you have this abnormality, you are unlikely to ever know it.  The tendency to violence with this abnormality is largely discredited, most evidence shows no abnormal tendencies in these people.  See the website below for more information and read the special chapter in the referenced book for an even more fascinating analysis of this question.\n\nEdit:\nI have looked into it a bit more and have found that the name of the condition is Jacobs Syndrome.  As to the question about whether it is possible, it certainly is possible.  It happens during meiosis II, when there is nondisjunction of sister chromatids of the Y chromosome, resulting in both sister chromatids in one cell and none in the other cell.  Nondisjunction means that the chromatids are normally supposed to split apart, one going into each cell, but that doesn't happen.
1072996
.\nThere will not be normal synapsis during zygotene of meiosis because one chromosome will not have a mate. A child may be born but the chances are that it will not be normal at all. Probably abort before birth. This is for a 47 chromosome male, and a 47 chromosome female, when the extra chromosome is an autosome.\n\nAn XXY is called a Klienfelter syndrome, sperms are usually not produced, breast development is common, voice tend to be higher pitched. The phenotype is male because of the y chromosome. Homosexuality is not mentioned.\n\nThe XXX female is sometimes fertile and can mate with a fertile XY male. There is a possibility that this female can mate with a XYY fertile male. This represents one of the few times a 47 female may mate with a 47 male and have normal children.
382442
Yes, the Y-chromosome is shrinking.\n\nThe reason is due to recombination. Recombination increases the effectiveness of selection, meaning that more "good" mutations are kept and more "bad" mutations are removed.\n\nThe X-chromosome can recombine during meiosis, but the Y-chromosome cannot. Therefore, the Y-chromosomes cannot repair "bad" mutations. These mutations build up on the Y-chromosome over time. Some of these mutations can cause the Y-chromosome to shorten. In some species, like Drosophila, the Y-chromosome is no longer present! Females are XX while males simply have an X chromosome!
1029470
Are you referring to Klinefelter's syndrome?\n\nKlinefelter's syndrome is a condition caused by a chromosome nondisjunction in males; affected individuals have a pair of X sex chromosomes instead of just one, and is associated with additional risk for some medical conditions. It is named after Dr. Harry Klinefelter, a medical researcher at Massachusetts General Hospital, Boston, Massachusetts, who first described this condition in 1942.\n\nCause\nThe XXY chromosome arrangement is one of the most common genetic variations from the XY karyotype, occurring in about 1 in 500 to 1000 male births. Because of the extra chromosome, individuals with the condition are usually referred to as "XXY Males", or "47,XXY Males" rather than as "suffering from Klinefelter's syndrome."\n\nIn mammals with more than one X chromosome, the genes on all but one X chromosome are barred from being expressed. This happens in XXY males as well as XX females. A few genes, however, have corresponding genes on the Y chromosome and are not barred. These triploid genes in XXY males may be responsible for symptoms associated with Klinefelter's syndrome.\n\nThe first published report (Jacobs & Strong 1959) of a man with a 47,XXY karyotype was by Patricia A. Jacobs and Dr. J.A. Strong at Western General Hospital in Edinburgh, Scotland in 1959. It was found in a 24-year-old man who had signs of Klinefelter syndrome. Dr. Jacobs described her discovery of this first reported human or mammalian chromosome aneuploidy in her 1981 William Allan Memorial Award address (Jacobs 1982).\n\nSigns and symptoms\nXXY males are almost always sterile, and some degree of language impairment may be present. In adults, possible characteristics vary widely and include little to no signs of affectedness, a lanky, youthful build and facial appearance, or a rounded body type with some degree of gynecomastia (increased breast tissue). Gynecomastia to some extent is present in about a third of individuals affected, a higher percentage than in the XY population. The far end of the spectrum is also associated with an increased risk of breast cancer, pulmonary disease, varicose veins, and osteoporosis, risks shared with women.\n\nRare X-linked recessive problems occur even more infrequently in XXY males, since these conditions are transmitted by genes on the X chromosome, and people with two X chromosomes are typically carriers rather than affected.\n\nThere are many variances within the XXY population, just like in the 46,XY population. While it is possible to characterise 47,XXY males with certain body types, that in itself should not be the method of identification as to whether someone has 47,XXY or not. The only method of identification is karyotype testing.\n\nThe condition was first clinically described in 1942 by Klinefelter in Boston. The cause was not found until 1959.\n\nTreatment\nThe condition is irreversible, but its symptoms can be altered in a number of ways, including testosterone treatment and other therapies.\n\nWhile the gender identity of people with XXY karyotype is generally stable, the number of people with gender identity disorder among the whole seems to be higher than could statistically be expected if those cases were indeed, as the current medical opinion assesses, mere coincidences of people having both gender identity disorder and Klinefelter's independently from each other. The observation on gender identity is based on the reports of support groups for transgender and transsexual people; no scientific study on this subject has been done. The fact that a person undergoing treatment for gender identity disorder has Klinefelter's syndrome is often missed, or the patient is not told, although in many jurisdictions this additional diagnosis can have legal consequences, for example regarding name change or medical treatment having to be adapted.\n\nVariations\nThe 48, XXYY (male) syndrome occurs 1 in 17,000 birth
758514
that's really rare but it has happened before.  It has to do with the chromosomes and how they are activated and crossed over and everything...it's complicated.
656270
having xxx sex chromosome.or a female with turner syndrome
430415
To answer your question....yes.  The egg cells of the female all carry X chromosomes.  The sperm cells can carry either X or Y.  So basically, the sex of a mammal depends on the male, and which particular sperm fertilizes the egg (X).  If an X sperm fertilizes the egg, you have XX, which is a female, and if a Y sperm fertilizes it, you have XY, which is male.  This is why some sex-linked traits are more visible in males, such as color blindness, but that's a whole different post.
1052965
Men are XY, women are XX, right? The only genetic difference between men and women is whether they have a Y sex chromosome or not. Sexual characteristics such as genitals and breasts are encoded on the X and Y chromosomes, but NOT NIPPLES. Nipple genes are not on the X or Y chromosomes so we all have them. Women have genes in their XX genome to build mammary glands beneath their nipples -- men don't.
208675
We normally have 23 pairs of chromosomes, that is, 46 chromosomes in total. When they're seen inside of a cell nucleus, they just look like similar V , X and Y shaped little dark spots, but the specialists are able to order them and know which ones belong to each pair (i.e. are homologous). They've labeled the pairs from 1 to 23 (the 23rd pair is the XX or XY sex chromosomes). \nIn Down syndrome, there is an extra chromosome. If you just looked at an image of the nucleus, you'd just count 47 chromosomes. But it has been determined that the "extra" one is a duplicate of one of the members of pair 21. \nIn the case of other duplicate chromosomes, the effects are not Down syndrome. Most cases of chromosomal duplication are lethal.
40538
So what will they do, I know there are people born with both organs of male and female.. How will you do this? Very interesting...
322976
Just a clarification-There arent any "true" hermaphrodites in humans-That would indicate that they could both become pregnant *and* impregnate another.  Humans sometimes can have partial external genitalia of both male and female, but do not have both functional testes and functional ovaries.\nAny medical school library would have a great deal of information on this.