Where does XXX Syndrome and XYY come from?

Question

I know what it is but, WHERE does it come from? How does it start out?

Answer 1

What causes XXX syndrome in girls?

Answer

XXX syndrome, also called triple X syndrome, is a rare chromosomal abnormality that affects only females. As the name implies, females with XXX syndrome have three X chromosomes instead of the usual two. The cause of this gene defect isn't known.

XXX syndrome is the most common X chromosome disorder in females. In many cases, XXX syndrome causes no signs or symptoms. When signs and symptoms do appear, they may include:

* Tall stature
* Small head (microcephaly)
* Vertical skinfolds that may cover the inner corners of the eyes (epicanthal folds)
* Delayed development of certain motor skills, speech and language
* Learning disabilities such as dyslexia
* Infertility

A doctor may make a diagnosis of XXX syndrome by a chromosome analysis of a blood sample. The disorder may be found during prenatal genetic testing, such as amniocentesis. Often, XXX syndrome is identified in older children as part of an evaluation of developmental delay.

A female with XXX syndrome may be referred to a pediatric geneticist for counseling. There's no cure for XXX syndrome. When possible, treatment is directed at managing the signs and symptoms of the disorder.
http://www.mayoclinic.com/health/triple-x-syndrome/AN00351


The name XYY males

Klinefelter's syndrome with an extra X-chromosome (47,XXY) and Turner's syndrome with lack of X-chromosome material (45,X) have their names after the physicians who first described the syndromes in 1942 and 1937, respectively. Since 1960 geneticists have given new names to chromosome aberrations from the chromosome constitution and not as previously from the name of the person who first described the chromosome aberration.

When Sandberg and co-wokers in 1961 found the chromosome constitution 47,XYY, the name became XYY males in accordance with triple-X women with the chromosome constitution 47,XXX as first described by Jacobs and Strong in 1959.

How frequent is XYY?

XYY is found in approximately 1 per 1,000 men. Thus in Denmark with a population of 5 mill. there are approximately 3,000 XYY males.

What is the cause of XYY?

Males usually have only one X and one Y, that is the chromosome constitution 46,XY. Males with XYY have two Y chromosomes (47,XYY). In rare cases there is a combination of Klinefelter's syndrome and XYY with the chromosome constitution 48,XXYY.

The chromosome constitution 47,XYY is found in approximately 80% of males with double Y. In 10% there is both a double X and a double Y, that is the above mentioned chromosome constitution 48,XXYY~ and in the last 10% a so-called chromosome mosaicism with normal chromosome constitution 46,XY in part of the cells and 47,XYY in the rest.

What is the cause of the chromosome aberration XYY?

Today we know no definite causes of the chromosome aberration which leads to XYY, that is an abnormal partition (a so-called non-disjunction) of the Y chromosome leading to two instead of one Y chromosome in the cells.

Does a new-born XYY boy present any signs of this?

No! Boys with XYY are usually quite normally developed at birth with normal birth weight and length without any physical abnormalities.

How is the development of these boys during childhood?

Boys with XYY are often more physically active than their brothers, and if this activity is well accepted and canalised out in play, sport and other physical activities together with the parents and together with other children, this condition is in no way negative.

These boys have a tendency to a somewhat delayed emotional maturity, and this in connection with a slightly increased tendency to learning problems in school creates a need for early and adequate stimulation.

It is important that these boys at an early age attend a good day institution - kindergarten, and that there is a close co-operation between parents and the staff in the day institution -kindergarten. If the language development is delayed it is important to get a speech pedagogue for a while.

It is, however, a general condition that XYY boys develop quite normally during childhood.

Are XYY boys of average intelligence?

In a study of 60 XYY boys found among consecutively new-born children in USA, Canada, Scotland and Denmark intelligence was found to be normal with an average 10 of 105, both for the XYY boys and for the control group. In a study of 12 unselected Danish adult XYY males by Alice Theilgaard, there was no significant difference in intelligence compared with a control group.
http://www.aaa.dk/TURNER/ENGELSK/XYY.HTM

Answer 2

"XXX syndrome (also called Triple X syndrome or Trisomy X) affects females who have three X chromosomes, instead of the usual two. It is the most common X-chromosome disorder in females. Triple X is a random mutation, usually inherited from the mother. Parents who have a daughter with Triple X usually do not have to worry about their later children having the syndrome. The mutation occurs in one in every 1,000 to 3,000 newborn girls, but it is often not diagnosed until later in life."

Maybe this site can help you?

http://www.med.umich.edu/1libr/yourchild/xxxsyn.htm

Answer 3

I think it's that meiosis doesn't work right, so that when the two halves of the chromosome are supposed to split they don't. I might be wrong though.