Podcast
Questions and Answers
What is the result of a large deletion of genetic material?
What is the result of a large deletion of genetic material?
What type of deletion involves a single break of the terminal part of a chromosome?
What type of deletion involves a single break of the terminal part of a chromosome?
What is the characteristic cry of a newborn with Cri-du Chat syndrome?
What is the characteristic cry of a newborn with Cri-du Chat syndrome?
What is the incidence of Cri-du Chat syndrome?
What is the incidence of Cri-du Chat syndrome?
Signup and view all the answers
What is the result of a duplication of a chromosome part?
What is the result of a duplication of a chromosome part?
Signup and view all the answers
What is the type of inversion that involves both p and q arms with the centromere?
What is the type of inversion that involves both p and q arms with the centromere?
Signup and view all the answers
What is the method used to detect microdeletions that cannot be detected by karyotype?
What is the method used to detect microdeletions that cannot be detected by karyotype?
Signup and view all the answers
What is the type of deletion that results in Cri-du Chat syndrome?
What is the type of deletion that results in Cri-du Chat syndrome?
Signup and view all the answers
What is the characteristic of Interstitial deletion?
What is the characteristic of Interstitial deletion?
Signup and view all the answers
What is the feature of Prader-Willi syndrome?
What is the feature of Prader-Willi syndrome?
Signup and view all the answers
Study Notes
Deletion and Structural Abnormalities
- Deletion results in monosomy, usually incompatible with survival to term
- There are two types of deletions: terminal deletion and interstitial deletion
Terminal Deletion
- Involves a single break of the terminal part of a chromosome, resulting in loss of the broken part
- Example: Cri-du Chat syndrome (46,XX,5p- or 46,XY,5p-)
- Characteristics of Cri-du Chat syndrome:
- Deletion of the short arm of chromosome 5
- Incidence: 1 per 20,000 to 1 per 50,000 births
- Underdevelopment of larynx, resulting in a characteristic cat-like cry (Mewing cry)
- Mental retardation
- Microcephaly and facial anomalies
Interstitial Deletion
- Involves two breaks, resulting in loss of the intervening portion of the chromosome
- Some interstitial deletions can occur as micro-deletions, which cannot be detected by karyotype and require FISH technique for detection
- Examples: Prader-Willi syndrome (interstitial deletion of paternal chromosome 15, 15q11–q13) and Angelman syndrome (interstitial deletion of maternal chromosome 15, 15q11–q13)
Other Structural Abnormalities
- Duplication: extra copies of a chromosome part
- Inversion: involves two breaks along the chromosome, resulting in reversal of a given segment
- Pericentric inversion: inverted segment involves both p and q arms with centromere
- Paracentric inversion: inverted segment involves only one arm (p or q)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers chromosomal deletions, including terminal and interstitial deletions, and their effects on the genome, such as Cri-du Chat syndrome.
