What is an example of non disjunction?

What is an example of non disjunction?

Nondisjunction Examples Nondisjunction causes abnormal number chromosomes in all the cells called aneuploidy or in some cells called mosaicism. Some of the important examples are: Down’s syndrome – Trisomy of autosomes, i.e. chromosome 21. It contains one extra chromosome 21.

Which disorder is due to non disjunction?

Nondisjunction causes errors in chromosome number, such as trisomy 21 (Down syndrome) and monosomy X (Turner syndrome). It is also a common cause of early spontaneous abortions.

What type of mutation is Klinefelter syndrome?

Klinefelter syndrome (sometimes called Klinefelter’s, KS or XXY) is where boys and men are born with an extra X chromosome. Chromosomes are packages of genes found in every cell in the body. There are 2 types of chromosome, called the sex chromosomes, that determine the genetic sex of a baby.

Does nondisjunction occur in males?

Theoretically, non-disjunction may occur in both the male and female germ cells at either the first or second meiotic division and may give rise to a considerable variety of non-disjunctional types in the progeny.

How does Klinefelter syndrome affect a person?

Klinefelter syndrome may adversely affect testicular growth, resulting in smaller than normal testicles, which can lead to lower production of testosterone. The syndrome may also cause reduced muscle mass, reduced body and facial hair, and enlarged breast tissue.

What is nondisjunction and what does it result in?

Nondisjunction is the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes. [

Where does nondisjunction occur?

Nondisjunction, in which chromosomes fail to separate equally, can occur in meiosis I (first row), meiosis II (second row), and mitosis (third row). These unequal separations can produce daughter cells with unexpected chromosome numbers, called aneuploids.

What are two characteristics of Klinefelter syndrome?

Taller than average stature. Longer legs, shorter torso and broader hips compared with other boys. Absent, delayed or incomplete puberty. After puberty, less muscle and less facial and body hair compared with other teens.

How does nondisjunction result in Klinefelter syndrome?

However, because of nondisjunction, an egg cell or a sperm cell can also end up with an extra copy of the X chromosome. If an egg cell with an extra X chromosome (XX) is fertilized by a sperm cell with one Y chromosome, the resulting child will have Klinefelter syndrome.

Can Klinefelter’s be due to nondisjunction during meiosis in the male?

The 47,XXY karyotype of Klinefelter syndrome spontaneously arises when paired X chromosomes fail to separate (nondisjunction in stage I or II of meiosis, during oogenesis or spermatogenesis). Maternal and paternal meiotic nondisjunction each account for approximately 50% of Klinefelter syndrome cases.

How does Klinefelter syndrome occur in meiosis?

How is Klinefelter’s diagnosed?

Blood or urine samples can reveal abnormal hormone levels that are a sign of Klinefelter syndrome. Chromosome analysis. Also called karyotype analysis, this test is used to confirm a diagnosis of Klinefelter syndrome. A blood sample is sent to the lab to check the shape and number of chromosomes.