Genetics and Pedigree Analysis

Question 0

Number of genes that can give rise to a similar phenotype

Answer 0

Clinical/Genetic Heterogeneity

Question 1

Intrafamilial variability in disease manifestation

Answer 1

Variable expressivity

Question 2

Being attracted to the same phenotype

Answer 2

Assortative mating

Question 3

Confounding factors in recognizing patterns of inheritance

Answer 3

Variable expressivity, clinical/genetic heterogeneity, sex-influenced/limited gene expression, assortative mating, small paternity size

Question 4

Each offspring has 50% chance of inheriting gene from affected parent; males and females affected equally; no skipping of generations

Answer 4

Autosomal Dominant

Question 5

Mutated gene in achondroplasia and type of inheritance

Answer 5

FGF3; autosomal dominant

Question 6

Affected gene in Crouzon Syndrome; mode of inheritance

Answer 6

FGF2; autosomal dominant

Question 7

Manifested in many consanguinous unions

Answer 7

Autosomal recessive

Question 8

Both parents must be carriers for the offspring to manifest the phenotype

Answer 8

Autosomal recessive inheritance

Question 9

Mode of inheritance: Harlequin Syndrome

Answer 9

Autosomal Recessive

Question 10

Mode of inheritance: mucopolysaccharidosis (Hurler)

Answer 10

Autosomal Recessive

Question 11

Mode of inheritance: Maple Syrup Urine Syndrome

Answer 11

Autosomal recessive

Question 12

Mode of inheritance wherein all daughters of affected males are carriers

Answer 12

X-linked recessive

Question 13

TRUE/FALSE: there is no father-son transmission of x-linked disorders

Answer 13

TRUE

Question 14

Mode of Inheritance: Mucopolysaccharidosis - Hunter

Answer 14

X-linked recessive

Question 15

Mode of Inheritance: Duchenne Muscular Dystrophy

Answer 15

X-linked recessive

Question 16

Mode of inheritance wherein female child of affected mother has 50% chance of acquiring the mutation

Answer 16

X-linked dominant

Question 17

Mode of inheritance: when the father is affected, all female children but no male children are also affected

Answer 17

X-linked dominant

Question 18

Mode of Inheritance: Rett Syndrome

Answer 18

X-linked dominant

Question 19

Mode of inheritance determined by environmental factors wherein a trait will manifest only upon reaching a certain threshold

Answer 19

Multifactorial Inheritance

Question 20

Role of folic acid in pregnancy

Answer 20

Prevents spina bifida and/or anencephaly - multifactorial inheritance

Question 21

Medium for pure Maternal Inheritance

Answer 21

Mitochondrial inheritance

Question 22

Mixture of mutated and nonmutated mitochondria

Answer 22

Heteroplasmy

Question 23

Expansion of a segment of DNA that contains a repeat of 3 nucleotides

Answer 23

Triplet Expansion Disorder

Question 24

Diseases involving triplet expansion Disorder

Answer 24

Huntington’s, Fragile X, myotonic dystrophy

Question 25

Example of genomic imprinting

Answer 25

Prader-Wili and Angelman Syndromes - deletion at Chromosome 15

Question 26

Epigenetic mechanism by which genes are tagged for expression or suppression

Answer 26

Methylation