Chapter 4 Flashcards
Genes and Genetic Diseases
RED SLIDE Genetic testing can be applied in a \_\_\_\_\_ of context: \_\_\_\_\_\_\_\_\_ diagnosis such as: \_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_
variety prenatal amniocentesis chorionic villus sampling preimplantation genetic diagnosis
carried at 16 weeks gestation, involves the withdrawal of ______ from the ______
this test can detect _________ like ________ and ________ can be detected as an elevation in _______ level in the fluid
________ - indicates a _______ when an increase in which protein is evident
amniocentesis
amniotic fluid, uterus
neural tube defects, spina bifida, anencephaly, alpha fetoprotein
amniocentesis, neural tube defect
carried out at 10 to 12 weeks gestation, this is performed by extracting a small amount of _________ directly from the ______
the most clinically useful technique for prenatal diagnosis of _________ abnormalities at ___ months gestation
chorionic villus sampling villus tissue chorion chromosomal 3
chromosomal ________
- ________
- is usually the cause of aneuploidy
- is the failure of homologous chromosomes or sister chromatids to separate normally during _____ or ____
the most common cause of ________ is maternal ________
aberrations nondisjunction mitosis, meiosis down syndrome nondisjunction
example of \_\_\_\_\_\_ aneuploidy is the best known example of aneuploidy - trisomy \_\_\_ - occurs 1 in \_\_\_\_ live births - manifestations: \_\_\_\_\_ challenges, low \_\_\_\_ bridge, \_\_\_\_\_ folds, \_\_\_\_\_\_ tongue, \_\_\_, \_\_\_\_ ears, and poor \_\_\_\_\_ risk increases with \_\_\_\_\_ age has an increased risk of \_\_\_\_\_\_\_\_\_\_\_\_ disease, \_\_\_\_\_\_ infections, and \_\_\_\_\_\_\_ IQ of \_\_\_-\_\_\_
autosomal down sydrome 21 800 mental nasal epicanthal protruding flat, low-set muscle tone maternal congenital heart respiratory leukemia 25-70
females have only one \_\_\_ chromosome denoted as karyotype \_\_\_,X characteristics include: absence of \_\_\_\_ \_\_\_\_ stature \_\_\_\_\_ of the neck \_\_\_\_\_ spaced \_\_\_\_ high number of \_\_\_\_\_\_\_ X chromosome that is usually inherited from the \_\_\_\_\_\_ occurs in 1 in \_\_\_\_\_ \_\_\_\_ births teenagers receive \_\_\_\_\_\_ absent of \_\_\_\_\_\_\_\_ X chromosomes with only a \_\_\_\_\_ X chromosome
sex chromosome aneuploidy X 45 ovaries short webbing widely, nipples aborted fetuses mother 2500 female estrogen homologous single
individuals with at least one ___ and two ___ chromosomes
characteristics include:
____ appearance
female like _____ (______)
small ____
sparse _____
1 in ____ ____ births
some individuals can be _____ and _____; will have ____ appearance; abnormalities will ____ with each __; can also have an extra ___ chromosome
disorder increases with _______
____, XXY
chromosomal variation that causes this syndrome ______ of _____ chromosome in the _____
sex chromosome aneuploidy Klinefelter's syndrome Y, X male breasts, gynecomastia testes body hair 1000, male XXXY, XXXXY male increase, X Y maternal age 47 nondisjunction, X, mother
site is on the ___ arm of the X chromosome. has an elevated number of ____ DNA sequences
is the ___ most commonly recognized genetic cause of __________
fragile syndrome fragile X syndrome long repeated second mental retardation
chromosomal abnormalities are the leading cause of:
________ and ________
mental retardation
fetal miscarriage
elements of formal genetics
________: is the composition of genes at a given locus or the individuals makeup
________: is the outward appearance of an individual
results from the _____ and the ______
example: infant with phenylketonuria (PKU) has the PKU _________
if left untreated, the infant will have cognitive impairments, which is the PKU ______
if treated, the infant will still have the genotype but can have a _______
genotype phenotype genotype environment genotype phenotype normal phenotype
transmission of genetic diseases
four major types of genetic:
autosomal dominant
autosomal recessive
x-linked dominant
x-linked recessive
diseases are rare
occurs in fewer than 1 of ___ individuals
the union of a ____ parent with an affected ______ parent usually produces the _____ offspring
an affected parent can pass either a disease gene or a normal gene to his or her children; each event has a probability of ___; on average half will be ______ and will express the disease half will be normal
autosomal dominant inheritance 500 normal heterozygous affected 0.5 heterozygous
is rare, but many individuals are _____
abnormal allele is ____ and the person must be _____ to express the disease
trait usually appears in the ______, not the _____
example: ________
- gene forms _____ with defective transport, which leads to a ___ imbalance that results in abnormally thick, dehydrated _____. the ____ and ____ are affected; the person does not past __ years of age
characteristics:
condition is expressed _____ in males and females
is observed in ______ but not ____
approximately ___ of offspring will be affected
______ may be present: marriage between related individuals
autosomal recessive inheritance carriers recessive homozygous children parents cystic fibrosis sodium channels salt mucus lungs, pancreas 40 equally siblings, parents one quarter consanguinity
known as inbreeding
____ of the two related individuals
offspring are termed ___
proportion of shared genes depends on the _____ of the biologic relationship
dramatically increases the ______ risk of _____ disorders
-offspring of marriages of ____ cousins who are affected by genetic diseases is approximately double that of the general population
consanguinity mating inbred closeness recurrence recessive first
is a disorder that involves X and Y chromosomes
_____ are uncommon because the __ chromosome contains relatively few genes
females: have two X chromosomes; can be _____ for the disease and for normal, or _______
males: have one X chromosome; are always _____; if inherits an X recessive gene then he will ____ the disease because no normal allele is present to counteract the diseased alleles; ____ are affected more often with X recessive conditions
x-linked inheritance y-linked y homozygous heterozygous hemizygous express males
