What is mosaic Klinefelter syndrome?
Klinefelter syndrome can be caused by: One extra copy of the X chromosome in each cell (XXY), the most common cause. An extra X chromosome in some of the cells (mosaic Klinefelter syndrome), with fewer symptoms. More than one extra copy of the X chromosome, which is rare and results in a severe form.
What does it mean when a person has mosaicism?
What is mosaicism? Mosaicism occurs when a person has two or more genetically different sets of cells in his or her body. If those abnormal cells begin to outnumber the normal cells, it can lead to disease that can be traced from the cellular level to affected tissue, like skin, the brain, or other organs.
What are the types of mosaicism?
On the base of cells affected, mosaicism can classify as two types.
- General mosaicism: Two or more cell lines are present in the entire organism.
- Confined Mosaicism: In Confined mosaicism, only particular body parts or organs (e.g., brain, heart, liver, etc. )
How common is Mosaic Klinefelter syndrome?
Klinefelter syndrome (KS), with an incidence of 1 in 600 male newborns, is the most common type of X chromosome aneuploidy. Individuals with KS are characterized by tall stature, decreased secondary sexual characteristics, small testicles, gynecomastia, and infertility.
What is the difference between Mosaic and non mosaic Klinefelter syndrome?
About 10% of patients with Klinefelter syndrome have a mosaic form (46XY/47XXY) in which the presence of sperm in the ejaculate and subsequent paternities have been reported (Emre Bakiricioglu et al., 2006). Men with non-mosaic Klinefelter syndrome have azoospermia, and are thus traditionally labelled as infertile.
Can a person be a mosaic?
Genetic mosaicism is the presence of DNA alterations in only some of the body’s cells. A person with mosaicism has a mixture of normal and mosaic DNA in the same type of cells (most of the samples tested in GWAS came from blood or cheek cells). Like a mosaic piece of art, mosaicism in humans is varied and complex.
Is Klinefelter syndrome a disability?
Most males with the 47,XXY karyotype have normal intelligence. Intellectual disability occurs in males with Klinefelter syndrome variants, who have a higher number of X chromosomes. About 70% of patients have minor developmental and learning disabilities.
How common is mosaic Klinefelter syndrome?
What is non mosaic Klinefelter?
Klinefelter syndrome is a common genetic condition. Affected non-mosaic men are azoospermic and have been labelled as infertile. Despite reports that these men can have children using assisted reproduction techniques, it is not common practice in the UK to offer sperm retrieval to these men.
Do all females have Barr bodies?
Since women have two X chromosomes, one being inactivated, a single Barr Body is present in female mammal cells while males typically have no Barr Body present since they have only one X chromosome.
What is the most common cause of mosaicism in females?
females are mosaic because X inactivation creates two populations of cells that differ regarding their active X, and because the same X chromosome is not expressed in every cells. In all her somatic tissues, she has mixture of cells, some expressing her maternal alleles, the others expressing the paternal ones..
What does mosaicism mean in biology?
Genetic mosaicism is defined as the presence of two or more cell lineages with different genotypes arising from a single zygote in a single individual. In contrast, if distinct cell lines derived from different zygotes, the term is now known as chimerism. Genetic mosaicism is a postzygotic mutation.
What is gonadal mosaicism and somatic mosaicism?
Germline mosaicism, also called gonadal mosaicism, is a type of genetic mosaicism where more than one set of genetic information is found specifically within the gamete cells; conversely, somatic mosaicism is a type of genetic mosaicism found in somatic cells.
Why is germline mosaicism difficult to diagnose?
Diseases caused by germline mosaicism can be difficult to diagnose as genetically-inherited because the mutant alleles are not likely to be present in the somatic cells. Somatic cells are more commonly used for genetic analysis because they are easier to obtain than gametes.
What is the difference between germline and somatic mosaicism?
Germline mosaicism can be present at the same time as somatic mosaicism or individually, depending on when the conditions occur. Pure germline mosaicism refers to mosaicism found exclusively in the gametes and not in any somatic cells.