What is XYY syndrome? Show
Most people have 46 chromosomes in each cell. In males, this typically includes one X chromosome and one Y chromosome (XY). XYY syndrome is a genetic condition that occurs when a male has an extra copy of the Y chromosome in each of their cells (XYY). Sometimes, this mutation is only present in some cells. Males with XYY syndrome have 47 chromosomes because of the extra Y chromosome. This condition is also sometimes called Jacob’s syndrome, XYY karyotype, or YY syndrome. According to the National Institutes of Health, XYY syndrome occurs in 1 out of every 1,000 boys. For the most part, people with XYY syndrome live typical lives. Some may be taller than average and face learning difficulties or speech problems. They may also grow up with minor physical differences, such as weaker muscle tone. Besides these complications, though, males with XYY syndrome don’t usually have any distinguishing physical features, and they have normal sexual development. XYY syndrome is the result of a random mix-up, or mutation, during the creation of a male’s genetic code. Most cases of XYY syndrome are not inherited. Researchers don’t believe that there’s any genetic predisposition to it. That is, men with XYY syndrome are not more or less likely than other men to have children with XYY syndrome. The random error can occur during the formation of sperm or at different times during the formation of an embryo. In the latter case, a male may have some cells that are not affected. This means that some cells may have XY genotype while others have XYY genotype. The signs and symptoms of XYY syndrome differ from person to person and age to age. Symptoms in a baby who has XYY syndrome can include:
Symptoms in a young child or teenager with XYY syndrome can include:
In adults, infertility is a possible symptom of XYY syndrome. XYY syndrome may remain undiscovered and undiagnosed until adulthood. That’s when fertility problems such decreased sperm counts alert doctors to a possible condition. Genetic disorders can be diagnosed with a chromosome analysis. If your doctor can’t find another explanation for symptoms that may indicate XYY syndrome, they may ask you to undergo a chromosome analysis to check for XYY syndrome. XYY syndrome can’t be cured. But treatments can help reduce its symptoms and effects, especially if it’s diagnosed early. People with XYY syndrome can work with healthcare providers to address any symptoms they may have, such as speech and learning problems. As they get older, they may want to work with a reproductive specialist to address any infertility concerns. The following treatment options may help address some of the most common effects of XYY syndrome. Speech therapy: People with XYY syndrome may have speech or motor skill disabilities. Healthcare professionals can help treat these issues. They can also provide plans for future improvements. Physical or occupational therapy: Some younger people with XYY syndrome have delayed motor skill development. They may also have difficulty with muscle strength. Physical therapists and occupational therapists can help people overcome these issues. Educational therapy: Some people with XYY syndrome have learning disabilities. If your child has this syndrome, talk with their teacher, principal, and special education coordinators. Arrange a schedule that’s best suited to your child’s needs. Outside tutors and educational instruction may be necessary. People with XYY syndrome can — and very often do — live completely normal lives with the condition. In fact, XYY syndrome can remain undiagnosed throughout a person’s lifetime. If it is diagnosed, however, individuals with XYY syndrome can find the help they might need. Differences in sex development (DSD) is a group of rare conditions involving genes, hormones and reproductive organs, including genitals. It means a person's sex development is different to most other people's. Sometimes the term Disorders of Sex Development is used, as is Variations in Sex Characteristics (VSC) or Diverse Sex Development. Some adults and young people with DSD prefer to use the term intersex. You or your
child may have sex chromosomes (bundles of genes) usually associated with being female (XX chromosomes) or usually associated with being male (XY chromosomes), but reproductive organs and genitals that may look different from usual. This happens because of a difference with your genes or how you respond to the sex hormones in your body, or both. It can be
inherited, but there is often no clear reason why it happens. The most common times to find out that a person has a DSD are around the time of their birth or when they're a teenager. There are many different types of DSD. Some examples are: Some people have XX (usual female) chromosomes with ovaries and a womb, but their genitals may not look the
same as many females. For example, they may have a more developed clitoris and their vagina may be closed. Doctors refer to this condition as 46,XX DSD. The most common cause is congenital adrenal hyperplasia (CAH). A person who has CAH lacks an enzyme (chemical substance) that their body needs to make the hormones cortisol and aldosterone. Without these hormones, their body produces more androgens (sex hormones that are naturally higher in males). If the child is female, the raised androgen levels before birth can cause their genitals to look different, such as a larger clitoris and a vagina that is not open in the usual place. CAH can also cause serious health issues, such as life-threatening kidney problems that need to be treated as soon as possible. Find more information and advice from the CAH support group. Genes usually seen in males with genitals that look the same as most girls' and some internal male structuresSome people have XY (male) chromosomes, but their external genitals may develop in the usual way for girls or boys. Sometimes it's difficult at first to know whether their genitals are more similar to girls' or boys'. A person may have a womb and may also have testicles inside their body. Sometimes the testicles might not work properly. Doctors refer to this condition as 46,XY DSD. Many people with 46,XY DSD are boys born with the opening to pass urine towards the bottom of their penis or below it. For some, the scrotum appears separated into two smaller sacs, one on either side. Doctors call this peno-scrotal hypospadias and boys and men with this DSD can have either fully developed or partially developed testes. There are several causes of 46,XY DSD. One possible cause is androgen insensitivity syndrome (AIS), where the body "ignores" androgens or is insensitive to them. Sometimes a person's body does not respond at all or only partly responds to androgens. Complete insensitivity to androgens makes a person with XY chromosomes female. Partial insensitivity to androgens can mean that some people are male and others are female. Find support and more information about AIS from DSD Families or the AIS Support Group. Ordinary looking genitals but different sex developmentSome people have a chromosome pattern other than the usual XY or XX. They may have one X chromosome (XO), or they may have an extra chromosome (XXY). Their internal and external sex organs can be either male or female, but they may not go through a full physical development at puberty. For example, a child with female sex organs may not start having periods. Doctors call this sex chromosome DSD. One type is Klinefelter syndrome, which is where a boy is born with an extra X chromosome (XXY). This can mean they do not produce the usual level of testosterone, the sex hormone responsible for the development of male characteristics, such as the testes and body hair. Testosterone is also important for bone strength and fertility in men. Find more information and support about Klinefelter syndrome. Another example of this type of DSD is Turner syndrome, which is where a girl is born with a missing X chromosome. Girls and women with Turner syndrome are often infertile and their height may be shorter than average. Find support and more information about Turner Syndrome. Female with usual external genitals, but without a wombSome females are born with an underdeveloped womb or without a womb, cervix and upper vagina. The ovaries and external genitalia look the same as most girls and women and they develop breasts and pubic hair as they get older. This is called Rokitansky syndrome. It's also known as Mayer-Rokitansky-Küster-Hauser (MRKH syndrome). The cause is not clear, but girls and women with Rokitansky syndrome/MRKH have XX chromosomes. Often the first sign of Rokitansky syndrome is that a girl does not start having periods. Sex involving the vagina may also be difficult because the vagina may be shorter than most women's. Not having a womb means that a woman cannot become pregnant, but it's sometimes possible to take eggs from their ovaries, fertilise them, and implant them in another woman's womb (surrogacy). For support and more information about Rokitansky syndrome at:
Sex characteristics usually seen in males or femalesSome people with a very rare type of DSD have both ovarian and testicular tissue (sometimes one ovary and one testis). Their genitals may appear female or male or could look different from either. Most people with this type of DSD have XX (female) chromosomes. The cause is not usually clear, but some people with the condition have been found to have genetic material that's usually seen on the Y chromosome appearing on their X chromosome. Doctors refer to this condition as 46,XX ovotesticular DSD. What happens after the birth of a babySometimes doctors check a baby for DSD soon after birth because of signs such as undescended testicles or if a baby's genitals look different. Tests may be done to help get a clear diagnosis and find out whether any immediate treatment is needed. Tests may include:
Your care team may advise you to delay registering your child's birth for a few days until the tests are complete, you have discussed the results with your child's care team and the sex of your baby is established or decided. Many forms of DSD do not require any medical care other than understanding the baby's development and knowing what to expect as they grow older. A specialist nurse in your care team can help you learn about DSD and a psychologist will help you address any concerns you have. You can find more information about what happens when your baby is born with genitals that look different in the First Days leaflet from DSD Families. Advice for parents of older childrenSometimes a DSD may be diagnosed if an older child does not go through puberty properly. For example, your child may not start showing the changes linked with puberty, or they may start puberty but not have periods. Speak to a GP if you have any concerns about your child's development at puberty. They can refer your child to a specialist. This will usually be a consultant paediatric endocrinologist, who specialises in hormones, or an adolescent gynaecologist. A team of specialist healthcare professionals will work with you to understand your child's condition and offer you and your child support and advice. A psychologist in the team can talk with you or your child about sexuality, relationships and body image among other subjects. Some people with DSD may need hormone therapy and psychological support. Some may want to think about altering their existing genitals, for example by using vaginal stretch techniques. Some people with DSD consider altering the appearance of their genitals by having surgery. If you think you have a DSDIf you think or know you have a DSD, information and support is available. Speak to a GP, as they'll be able to refer you to a team of specialist healthcare professionals. They can answer your questions, help you stay healthy and put you in touch with others with DSD if that's something you're interested in. Most people with a DSD stay with the gender linked to their sex at birth, which is the sex on their birth certificate. But if your legal sex does not represent who you are or how you identify, you may want to discuss your options with your care team. If you have a DSD and want to explore parenthood, you can also discuss this with your specialist care team. Where to get supportIf you have a DSD or you're the parent of a child with a DSD, you may find it useful to contact a group involving others with the same or similar experiences. These groups can often offer more information and advice about living with a DSD, and may be able to put you in contact with others who've been in a similar situation to you. You are welcome to ask your care team about people with experience of your diagnosis in your local area who are happy to be contacted. Page last reviewed: 15 August
2019 Which of the following chromosome combination is present in a typical female child?Girls and women typically have two X chromosomes (46,XX karyotype), while boys and men typically have one X chromosome and one Y chromosome (46,XY karyotype ).
Which theory of development has as one of its stages the sensorimotor stage that focuses on children viewing the world through senses and actions?The sensorimotor stage is the first stage of your child's life, according to Jean Piaget's theory of child development. It begins at birth and lasts through age 2. During this period, your little one learns about the world by using their senses to interact with their surroundings.
Which of the following is necessary for proper depth perception?In order to have proper depth-perception and perceive 3D an individual must have: Accommodation – lenses in the eyes must change shape and maintain clear focus as objects move. Aerial perspective – the ability to perceive contrast differences between nearby objects versus distant objects.
Which of the following describes a risk associated with crossWhich of the following describes a risk associated with cross-sectional research on IQ? A: In a cross-sectional study, the participants may move or die before the study has been completed.
|
Which of the following chromosomal combination is present in a typical male child?
zusammenhängende Posts
Urheberrechte © © 2024 nguoilontuoi Inc.
