Genetics 2

Question 1

Multiple CGG trinucleotide repeats are present in the 5’ noncoding region of the fragile X gene (_______)

Answer 1

FMR1

Question 2

During female meiosis _______ alleles can expand to 200-3,000 repeats in fragile X

Answer 2

Premature

Question 3

Highest # of repeats correlates with absence of _______ and presence of fragile X

Answer 3

FMR1 mRNA

Question 4

_______ abundant in brain and testes

Answer 4

FMR1 mRNA

Question 5

Aberrant ______ of FMR1 promoter causes a reduction of mRNA seen in affected males with fragile X

Answer 5

Methylation

Question 6

Has been shown to be a nucleo-cytoplasmic shuttling protein that selectively binds to a subset of mRNAs

Answer 6

FMR protein

Question 7

Has a role in postnatal brain development and dendrite maturation in animal models. Plays a role in prenatal and postnatal brain development in humans

Answer 7

FMR1

Question 8

Huntingtons, myotonic dystrophy, fragile X, and spinocerebellar ataxia type 1 all have

Answer 8

Anticipation

Question 9

Huntingtons, spinocerebellar ataxia type 1, and X-linked spinal and bulbar muscular atrophy have expansions in

Answer 9

Father

Question 10

Fragile X syndrome expansions in

Answer 10

Mother

Question 11

Fragile site FRAXE and myotonic dystrophy can have expansions in

Answer 11

Either parent

Question 12

Worsening of disease over several generations. Decrease in age of onset, increase in severity, increase in penetrance

Answer 12

Anticipation

Question 13

May also stem from ascertainment vial. Mildly affect ppl may escape detection and give rise to artificially low penetrance in an older generation

Answer 13

Anticipation

Question 14

AD. Myotonia, ptosis, cataracts, hypogonadism, frontal balding, ECG changes.

Answer 14

Myotonic dystrophy

Question 15

Defect is amplified trinucleotide repeat in 3’ untranslated region of protein kinase gene on Chr 19

Answer 15

Myotonic dystrophy

Question 16

Range of phenotypic manifestations of same genetic d/o, or phenotype

Answer 16

Variable expressivity

Question 17

Refers to presence of absence of phenotype

Answer 17

Penetrance

Question 18

Rectus to degree of manifestation of a disease that is penetrant

Answer 18

Variable expressivity

Question 19

Neurofibromatosis can exhibit

Answer 19

Variable expressivity

Question 20

Variability of the NF1 _______, even in families with the same NF1 gene mutation, suggests other factors are involved in determining the disease manifestation

Answer 20

Phenotype

Question 21

Variable phenotype in those with the same NF1 mutation is a case of

Answer 21

Polygenic inheritance in expressivity

Question 22

X-linked dominant trait with incomplete penetrance

Answer 22

Fragile X

Question 23

Obesity, hyperphagia, intellectual disability, hypogonadism, small hands and feet. Only maternal 15q

Answer 23

Prader-willi

Question 24

Severe intellectual disability, spasticity, and seizures. Only paternal 15q

Answer 24

Angelman

Question 25

Multiple genes, no environment

Answer 25

Polygenic inheritance

Question 26

Environmental and genetic factors combine to produce a phenotype

Answer 26

Multifactorial