©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
NU 116 EXAM 4: Module VIII Study
Guide
genetic disorder - Ans:✔✔-An abnormal condition that a person inherits through genes or
chromosomes
chromosome - Ans:✔✔-coiled strands of DNA carrying genes
- somatic cells are diploid (46)
- gametes are haploid (23)
somatic cells - Ans:✔✔-Any cells in the body other than reproductive cells, 46 chromosomes - diploid
gamete cells - Ans:✔✔-sex cells, 23 chromosomes - haploid
karyotype - Ans:✔✔-pictorial analysis of an individual's chromosomes
*placental tissue/amniocentesis can provide this*
Normal female karyotype - Ans:✔✔-46, XX, no Y chromosomes
Normal male karyotype - Ans:✔✔-46, XY
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trisomy - Ans:✔✔-3 copies of a chromosome instead of 2
monosomy - Ans:✔✔-missing a chromosome, individual has 45 chromosomes
mosaicism - Ans:✔✔--Occurs after fertilization
-Results in an individual with 2 different cell lines, each having a different chromosomal number
-More common in sex chromosomes
turner syndrome - Ans:✔✔-A chromosomal disorder in females in which either an X chromosome is
missing, making the person XO instead of XX, or part of one X chromosome is deleted.
two examples of mosaicism - Ans:✔✔-turner syndrome and klinefelter syndrome
Klinefelter syndrome - Ans:✔✔-A chromosomal disorder in which males have an extra X chromosome,
making them XXY instead of XY.
Abnormalities of Sex Chromosomes - Ans:✔✔-- occur in early embryonic stage
- examples include Turner's syndrome and Klinefelter's syndrome
autosomal dominant inheritance - Ans:✔✔-- 50% chance of passing on the gene if one parent is affected
- males and females are equally affected
- varying degrees of presentation
Page 2/37
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FIRST PUBLISH OCTOBER 2024
- disorders include: huntington's disease, myotonic dystrophy, fragile X syndrome
Huntington's disease - Ans:✔✔-chronic brain disease
s/s include tremors, impaired thinking, problems swallowing
Myotonic dystrophy - Ans:✔✔-muscular dystrophy, presenting in adulthood
s/s include weakness in feet/legs/hands, abnormal HR, muscle pain
examples of autosomal dominant disorders - Ans:✔✔-- huntington's disease
- myotonic dystrophy
- fragile x syndrome
autosomal recessive inheritance - Ans:✔✔-Carrier parents have a
- 25% chance of producing an affected child
- 25% chance of passing on abnormal gene
- *If child is clinically normal, 50% change child is a carrier*
- males and females equally affected
examples include: sickle cell, cystic fibrosis, and some metabolic disorders
Page 3/37
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FIRST PUBLISH OCTOBER 2024
X-linked recessive inheritance - Ans:✔✔-- no male to male transmission
- 50% chance carrier mother will pass abnormal gene to sons (affected)
- 50% chance carrier mother will pass abnormal gene to daughters (carrier)
- fathers affected cannot pass disorder to sons, but all daughters become obligate carriers
examples: hemophilia, muscular dystrophy, colorblindness
X-linked dominant inheritance1 - Ans:✔✔-VERY RARE
- no male to male transmission
- can be lethal in utero, newborn periods (Rett syndrome)
- affected fathers will have affected daughters but not sons
- vitamin D resistant rickets
multifactorial inheritance - Ans:✔✔-- no clear pattern of inheritance
- often a sex bias (eg: pyloric stenosis + males, cleft palate + females)
- increased incidence when multiple family members affected, increased risk with CLOSEST relatives
- cleft palate, heart defect, spina bifida, dislocated hips, clubfoot, pyloric stenosis
Page 4/37
FIRST PUBLISH OCTOBER 2024
NU 116 EXAM 4: Module VIII Study
Guide
genetic disorder - Ans:✔✔-An abnormal condition that a person inherits through genes or
chromosomes
chromosome - Ans:✔✔-coiled strands of DNA carrying genes
- somatic cells are diploid (46)
- gametes are haploid (23)
somatic cells - Ans:✔✔-Any cells in the body other than reproductive cells, 46 chromosomes - diploid
gamete cells - Ans:✔✔-sex cells, 23 chromosomes - haploid
karyotype - Ans:✔✔-pictorial analysis of an individual's chromosomes
*placental tissue/amniocentesis can provide this*
Normal female karyotype - Ans:✔✔-46, XX, no Y chromosomes
Normal male karyotype - Ans:✔✔-46, XY
Page 1/37
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
trisomy - Ans:✔✔-3 copies of a chromosome instead of 2
monosomy - Ans:✔✔-missing a chromosome, individual has 45 chromosomes
mosaicism - Ans:✔✔--Occurs after fertilization
-Results in an individual with 2 different cell lines, each having a different chromosomal number
-More common in sex chromosomes
turner syndrome - Ans:✔✔-A chromosomal disorder in females in which either an X chromosome is
missing, making the person XO instead of XX, or part of one X chromosome is deleted.
two examples of mosaicism - Ans:✔✔-turner syndrome and klinefelter syndrome
Klinefelter syndrome - Ans:✔✔-A chromosomal disorder in which males have an extra X chromosome,
making them XXY instead of XY.
Abnormalities of Sex Chromosomes - Ans:✔✔-- occur in early embryonic stage
- examples include Turner's syndrome and Klinefelter's syndrome
autosomal dominant inheritance - Ans:✔✔-- 50% chance of passing on the gene if one parent is affected
- males and females are equally affected
- varying degrees of presentation
Page 2/37
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
- disorders include: huntington's disease, myotonic dystrophy, fragile X syndrome
Huntington's disease - Ans:✔✔-chronic brain disease
s/s include tremors, impaired thinking, problems swallowing
Myotonic dystrophy - Ans:✔✔-muscular dystrophy, presenting in adulthood
s/s include weakness in feet/legs/hands, abnormal HR, muscle pain
examples of autosomal dominant disorders - Ans:✔✔-- huntington's disease
- myotonic dystrophy
- fragile x syndrome
autosomal recessive inheritance - Ans:✔✔-Carrier parents have a
- 25% chance of producing an affected child
- 25% chance of passing on abnormal gene
- *If child is clinically normal, 50% change child is a carrier*
- males and females equally affected
examples include: sickle cell, cystic fibrosis, and some metabolic disorders
Page 3/37
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
X-linked recessive inheritance - Ans:✔✔-- no male to male transmission
- 50% chance carrier mother will pass abnormal gene to sons (affected)
- 50% chance carrier mother will pass abnormal gene to daughters (carrier)
- fathers affected cannot pass disorder to sons, but all daughters become obligate carriers
examples: hemophilia, muscular dystrophy, colorblindness
X-linked dominant inheritance1 - Ans:✔✔-VERY RARE
- no male to male transmission
- can be lethal in utero, newborn periods (Rett syndrome)
- affected fathers will have affected daughters but not sons
- vitamin D resistant rickets
multifactorial inheritance - Ans:✔✔-- no clear pattern of inheritance
- often a sex bias (eg: pyloric stenosis + males, cleft palate + females)
- increased incidence when multiple family members affected, increased risk with CLOSEST relatives
- cleft palate, heart defect, spina bifida, dislocated hips, clubfoot, pyloric stenosis
Page 4/37
