chromosome disorders Flashcards
aberrations in chromosomes result from what?
loss, gain, or abnormal arrangement of one or more chromosomes.
what do aberrations lead to?
excess or deficient genetic material and thus protein
what is ploidy?
of complete homologous sets of chromosomes in a genome
aneuploidy?
different # of chromosomes; a loss or gain of a chromosome
what does autosomal aneuploidy cause?
birth defects and mental retardation
what does sex chromosome aneuploidy cause?
sexual infantilism and mild retardation
two examples of sex chromosome aneuploidy?
turner’s (x) or klinefelter’s (XXY)
trisomy means what?
3 of a chromosome
monosomy means what?
1 of a chromosome
extra chromosome 21 causes what? (trisomy 21)
down syndrome
what is a deletion?
breakage or loss of a portion of a chromosome leads to loss of specific genes in that deleted region
cri-du-chat is caused by what?
deleted region on short arm on chromosome 5
what is cleft palate caused by?
22q11.2 deletion
what causes renal oncocytoma?
deletion of terminal end of chromosome 1p and monosomy of chromosome 14
what’s a translocation?
breakage of 2 chromosomes with transfer of one broken segment to another
what causes chronic myelogenous leukemia?
translocation - philadelphia chromosome translocation bw chromosomes 9 and 22 t(9;22)
what is CML? (chronic myelogenous leukemia) accounts for how much adult leukemia?
bone marrow disease characterized by increased proliferation of wbc line, 20 % responsible for adult leukemias
what is isochrome formation? what results from this?
breaking of chromosome at centromere with one arm being duplicated; chromosome with 2 p’s or q’s
what is angelman syndrome caused by?
maternal isochromosome 15
breakage of chromosomes can lead to what other aberrations?
ring chromosome, dicentric chromosome, or paracentric and pericentric inversions
