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Flashcards in Genetic Diseases 2 Deck (28)
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1

Foxglove purple/white petals

2 loci involved, hmz at either = white; htz at both=purple

Complementation
-> 2 different hmz recessive mutations produce same phenotype

2

Human Deafness

Many loci affect hearing pathway - from outer ear to aud nerve and brain

Complementation

3

Colour Blindness

X-linked - (daltonism)

4

Lesch-Nyhan syndrome

Error in purine metabolism - self-mutilation, death

X-linked

5

Haemophilia

Factor VIII deficiency - blood can't clot properly

X-linked
mutation probably happened in Queen Victoria's father - who was old

6

Duchenne muscular dystrophy (DMD)

Detect age 3-5, fatal in 20s

X-linked/ X-chromosome inactivation
one remarkable case of MZtwins, each had inactivated a different X chromosome, 1 had DMD, 1 did not

7

Tortoiseshell cat

Patches of black and orange fur (black activ 1 X chr, orange the other)

X chr inactivation, XCI

8

Colourblindness in women

woman htz: some retinal cells normal, some colour-blind

X chr inactivation, XCI

htz woman can see even though some retinal cells are abnormal

9

Patau syndrome

Trisomy 13

chromosomal abnormality

10

Notch Wing

in Drosophila melanogaster
- chr deletion

11

Cri-du-chat

lose tip of chr 5
- chr deletion
- child voice sounds like cat

12

Globin, odorant-receptor gene families

chr duplication
increase genetic material progressively, then changes, get new but similar genes : families

13

Dm Bar eye

Bigger eye
- chr duplication
if cross 2 Bar eye: sometimes get double Bar eye + normal eye -- due to slippage

14

Myeloid leukemia

Translocation 5-11/ 9-22
-> myeloid line of blood
-> abnormal WBC in bone marrow

15

Burkitt's lymphoma

Translocation 8-14
-> B cells + impaired immunity

16

Down's syndrome

trisomy 21 / translocation 14-21

Aneuploidy
early aging, excess water in uterus - flat face, fingerprints

17

Edward's syndrome

trisomy 18

Aneuploidy
lethal - kidney, heart abnorm (sth w clenched fingers)

18

Klinefelter's syndrome

XXY, XYY male // XXX female

Aneuploidy
XXY is male but has some female characteristics - sometimes dont notice till fertility tests

19

Turner's syndrome

XO, female

Aneuploidy
If females normally have 1 inactivated, should be normal, right ?NO - heart stuff, diabetes,

20

Gynandromorphs

Half male half female - mosaic (due to error in mitosis in early dvp)

Somatic Aneuploidy
Dm one red eye one white

21

Modern wheat

is hexaploid

Allopolyploid
-triticale is another allopolyploid

22

banana, ginger, seedless melon

infertile triploids

¿? autopolyploid (modern manipulation)

23

Siamese cats

Fur colour det by mut in melanin gene - enzyme doesnt work at high temp

Temperature-sensitive mutations
-cooler parts of body ie ears/paws are dark cause cooler temp in extremities

24

White-blood in Dm

high temp light eyes/low temp dark eyes

Temperature-sensitive mutations
-use to study temp-sensitive period of dvp

- correlated w/ mutation in eye cryptochrome gene
- gene-env interaction

25

phenylketonuria, PKU

absent Phenylalanine hydroxylase, PAH
- gene-env interaction, chemical
- recessive
- can't break down Phe -> special diet

26

porphyria variegata

Defict in some enzyme - cant break down porphyin component of haemoglobin, it accumulates (light sensitive chemical)
- gene-env interaction, chemical
-inc pen __rec/dom
- neurolog sympt, light sensitivity, low doses of barbiturates lethal - maybe gave origin to werewolf legend // George III

27

factor V leiden thrombophilia

Disorder of blood clotting
incomplete penetrance, gene-env interaction, chemical
- dominant

28

Baldness

gene-env interaction, sex limitation
- dominant