Chromosomal Abnormalities pt.2 Flashcards
The transfer of a chromosome or a segment of it to a non-homologous chromosome
Translocation
An exchange of material between two different chromosome
Reciprocal Translocation
A break in the centromere causing the chromosomes’ arms to fuse
Robertsonian Translocation
Loss of a portion of a chromosome
Deletion
Abnormality that causes extra piece of a chromosome
Duplication
A position of one chromosome has been deleted from its normal place and inserted into another chromosome
Insertion
Fragmentation of a chromosome followed by reconstitution with a section inverted
Inversion
Inversion involves centromere
Pericentric Inversion
Inversion that does not include the centromere
Paracentric Inversion
Division of chromosomes at centromere transversely instead of longitudinally
Isochromosomes
Aberrant chromosome whose sticky ends have fused together forming a ring
Ring Chromosome
3 Abnormal Features for Chromosomal Abnormalities
Simian Crease
Micrognathia
Clinodactyly
Most common chromosomal aberration
Down Syndrome
Affected chromosome in down syndrome
Trisomy 21
Chromosome name(?) for Down Syndrome
47, XX/XY, +21
is 95% of cases for Down Syndrome
Non-disjunction
is 4% of cases for Down Syndrome
Translocatiom
is 1% of cases for Down Syndrome
Mosaicism
Delayed motor movement
Hypotonia
Curved pinky finger
Clinodactyly
Cry of the Cat
Cri du Chat
Caused by Deletion of about half of p arm of Chromosome 5
Cri du Chat
Affected organ in Cri du Chat
Larynx
Caused by deletion in 15q1.11-1.13 chromosome
Prader Willi
An agent/factor that causes malformation of embryo
Teratogen
Study of abnormal form
Dysmorphology
Refers to the assessment of birth defects and unusual physical features that have their origin during embryogenesis
Dysmorphology
Primary structural defect occurring during the development of a tissue or organ
Malformation
- Implies an abnormal intrauterine mechanical force
- Distorts a normally formed structure
Deformation
- Involves destruction of a fetal part w/c initially formed normally
Disruption
Refers to abnormal cellular organization or function of specific tissue types
Dysplasia
Pattern of multiple abnormalities occurring after 1 initiating defect
Sequence
Sequence w/c all abnormalities may be traced to 1 original malformation (renal agenesis)
Potter’s Syndrome
Group of malformations that occur together more often than expected by
chance, but in different combinations from case to case
Association
Particular set of multiple anomalies occurs repeatedly in a consistent pattern
Syndrome
