Chromosomal Abnormalities Flashcards
Define Structural chromosome abnormalities
Alterations to the chromosome
Condition: Jacobsen Syndrome
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Deletion of 11q
Effect: delayed development of motor skills and speech; and cognitive impairment
Condition: Wolf Hirschhorn Syndrome
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Chromosome 4 short arm deletion
Effect: Delayed growth and development, intellectual disability , low muscle tone and seizures
Condition: Charcot-Marie-Tooth Disease Type 1A
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Duplication of PMP22 gene on chromosome 17
Effect: Peripheral nerve neuropathy - experience weakness and wasting muscles and sensory loss
Condition: Down’s syndrome translocation
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Robertsonian translocation of long arm of chromosome 21 and long arm of chromosome 14
Effect: physical growth delays, mild to moderate intellectual disability, and characteristic facial features
Condition: Chromosome 9 Inversion disorder
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: A part of the chromosome breaks off and reattaches upside down
Effect: congenital anomalies, growth retardation, infertility, recurrent pregnancy loss, and cancer
Condition: Tay–Sachs Disease
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Insertion of part of a chromosome into chromosome 15 makes a defect in the gene that codes for protein HEX-A by causing a frameshift and it is not made
Effect: Deafness, blindness, paralysis etc
Condition: Ring chromosome 14 syndrome
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: A part of chromosome 14 breaks of and forms a ring, some of the chromosome is deleted in the process. * doesn’t always happen in ring disorders
Effect: Recurrent seizures, developmental delay and microcephaly
Condition: Turner syndrome
Chromosomal Abnormality:
Effect:
Chromosomal Abnormality: Isochromosomal disorder whereby a mirror image copy of the X chromosome’s q arm is made to replace the deleted p arm
Effect: Growth and sexual problems
Define Aneuploidy
an abnormal number of chromosomes which happens when some is missing one of a pair of chormosomes (monosomy) or has more than 2 (trisomy etc).
Define Down’s Syndrome
3 copies of chromosome 21 and can cause delayed development, learning disability, short stature and heart defects.
Define Turners Syndrome
females only have one X chromosome
Define Sperm Aneuploidy
Usually associated with increased DNA damage in the sperm and the risk is made worse by lifestyle eg. Tobacco smoking and environmental changes eg. Insecticides
