Autosomal Chromosomal Abnormalities
Embedded Files
Autosomal Abnormality
An autosomal abnormality refers to any deviation from the normal number or structure of autosomes (non-sex chromosomes).
Polyploidy: Involves an entire extra set of chromosomes (e.g., triploidy, where cells have three sets instead of two), affecting all autosomes. It is usually lethal in humans.
Aneuploidy: Refers to the gain or loss of specific autosomes (e.g., trisomy, where there is an extra chromosome like in Down syndrome [Trisomy 21], or monosomy, where one is missing). This can lead to developmental and functional abnormalities.
Aneuploidy
Aneuploidy: A condition where the number of chromosomes deviates from the species' normal count. In humans, this means having an extra or missing chromosome, disrupting the typical 46 (23 pairs) and causing genetic disorders or developmental issues.
Types of Aneuploidy:
Trisomy: Presence of an extra chromosome (three copies of one chromosome). Examples include:
Monosomy: Absence of one chromosome from a pair. Example:
Monosomy X (Turner Syndrome): Missing one X chromosome in females (45,X instead of 46,XX).
Polyploidy: Presence of more than two complete sets of chromosomes. This is rare in humans but common in plants and some animals.
Causes:
(1): Nondisjunction: The most common cause, where chromosomes fail to separate properly during meiosis, leading to gametes with an abnormal number of chromosomes.
(2): Errors in Cell Division: During mitosis or meiosis, errors can lead to cells with abnormal chromosome numbers. (3): Inherited Chromosomal Abnormalities: Some aneuploidies can be inherited from parents with chromosomal translocations or other abnormalities.
Examples of Aneuploid Conditions: Down Syndrome (Trisomy 21), Edward Syndrome (Trisomy 18), Patau Syndrome (Trisomy 13), Turner Syndrome (45,X), Klinefelter Syndrome (47,XXY)
Page updated
Google Sites
Report abuse