Chapter 6: Genetic and Developmental Disorder Flashcards
(25 cards)
the human DNA is organized into how many chromosomes, composed of how many pairs?
total of 46 chromosomes, composed of 23 pairs from each (mother and father)
how many pairs of chromosomes are autosomal?
22 pairs are autosomal
which pair of chromosomes is defined as the sex chromosomes?
the 23rd pair are the sex chromosomes (X and Y) which helps decide either male (XY) or female (XX)
what are the four groups of genetic disorders?
chromosomal abnormalities, mendelian single-gene disorders, non-mendelian single-gene disorders, and polygenic/ multifactorial disorder
chromosomal abnormalities generally result from?
an abnormal amount of chromosomes and alterations to the structure of one or more chromosomes
what does aneuploidy refer to?
an abnormal number of chromosomes either less than or greater than 46 chromosomes
what is an example of autosomal aneuploidy and why?
Down syndrome (trisomy 21) which means there is an extra copy of chromosome 21. This is because autosomal aneuploidy generally happens due to nondisjunction which is the failure of pairs to separate properly during 1st of 2nd meiotic division
trisomy 18 and trisomy 13 are examples of which aneuploidy, and what is another name for each?
examples of autosomal aneuploidy trisomy 18 ( Edwards syndrome) trisomy 13 (patau syndrome)
what are two examples of a sex chromosome aneuploidy?
klinefelter syndrome and turner syndrome
what are the difference in abnormal chromosome structure between meiosis and mitosis?
abnormal chromosome structure results from breakage and loss of rearrangement of chromosome pieces during meiosis or mitosis. meiosis is due to crossing over error where chromosome portions are lost, attached to the wrong chromosome or not attached correctly. mitosis is where there are opportunities for chromosomal breakage and rearrangement
true or false: the long arm is labeled the q arm, and the short arm is labeled the p arm.
true
what is cri du chat syndrome?
the deletion of part of the short arm (p arm) of chromosome 5
the location of the defective gene is found where, and the mode of transmission is defined as?
the location= autosomal or sex chromosomes
mode of transmission= dominant or recessive
Marfan syndrome is an example of an autosomal dominance disorder, falling under which type of tissue disorder?
connective tissue disorder
what are some clinical manifestations for Marfan syndrome?
patients typically present with tall, slender bodies, long/thin arms, fingers, and the aorta tends to be weaker
Marfan syndrome is traced to which mutation, and low levels of this cause..?
fibrillin 1 gene on chromosome 15
low levels of fibrillin leads to weakened connective tissue
what does Huntington disease affect?
neurologic function
an abnormal amount of this protein is produced in Huntington disease that causes nerve degeneration?
Huntington protein
what are some examples of autosomal recessive disorders?
albinism, phenylketonuria (PKU), and cystic fibrosis
true or false: do males always express the disease for a sex-linked (X-linked) disorder?
true; males always express the disease because they only have one X chromosome
what classifies polygenic traits, and what are some examples of these traits?
polygenic traits develop in response to more than one gene, and some examples are height, weight, and intelligence
true or false: multifactorial traits do follow clear cut modes but tend to “run in families”
false
what do teratogenic agents do?
interfere with cell proliferation, migration, or differentiation
what are some examples of teratogenic agents?
chemical and drugs: thalidomide
alcohol
infectious agents: viruses, rubella, toxoplasmosis, others, rubella, cytomegalovirus, herpes (TORCH)
radiation
