genetics

Question 1

likelihood passing on autosomal dominant

Answer 1

50%

Question 2

penetrance autosomal dominance

Answer 2

lack of clinical signs and symptoms even with gene (eg otoslerosis)

Question 3

spontaneous mutations

Answer 3

new gene eg achondroplasia most have normal parents

Question 4

2 heterozygote parents for autosomal recessive –> chance to offspring

Answer 4

25% homozygous affected // 50% carrier // 25% unaffected

Question 5

what conditions are generally autosomal dominant

Answer 5

structural (internal or external) // exceptions are hyperlipidaemia + hypokalaemia are dominant

Question 6

examples autosomal dominant

Answer 6

achondroplasia, porphyria, ehlers danlos, FAP, HHT, spherocytosis, HNPCC, huntingtons, myotonic osteogenesis impergecta, retinoblastoma, von willbebrand

Question 7

what conditions tend to be resessive

Answer 7

metabolic // exceptions are friederichs ataxia is recessive

Question 8

recessive conditions

Answer 8

CF // gilberts // haemochromatosis// sickle cell // thalassaemia // wilsons // severe von willebrans

Question 9

X linked dominant

Answer 9

alprts // retts // vit D resistant rickets (girls get them)

Question 10

X linked recessive conditions

Answer 10

affect males only (females are carriers) // androgen insensitivity // duchennes // colour blind // haemophilia A,B // G6PD // hunters

Question 11

inheritence mitochondrial disease

Answer 11

maternal line // dad will never pass on disease, mother always pill

Question 12

biopsy mitochondrial disease

Answer 12

red, ragged fibres

Question 13

clinical features downs at birth

Answer 13

face: upslanting eyes, epicanthic folds, spots in iris, small ears, flat occiput // single palmar crease // hypotonia // duodenal atresia // hirschprungs

Question 14

cardiac complication downs

Answer 14

endocardial cushian (ASD!!) // VSD // secundum ASD // TOF // patent ductus arteriosus

Question 15

older complications downs

Answer 15

subfertile // short // resp infections // glue ear // ALL // hypothyroid // alzheimers // atlantoaxial instability

Question 16

trisomy patau

Answer 16

13

Question 17

symptoms patau

Answer 17

microcephaly, small eyes, cleft lip, polydacytl

Question 18

trisomy edwards

Answer 18

micrognathia (small jaw), low ears, overlapping fingers

Question 19

turners syndrome genetics

Answer 19

45X

Question 20

symptoms turners

Answer 20

short // webbed next // bicupsid aortic valve, coarction // primary amenorrhoea // lympoedema // raised gonadatrophins (LH + FSH) // horseshoe liver //

Question 21

genetics fragile X

Answer 21

trinucleotide repeat

Question 22

symptoms fragile X

Answer 22

learning difficulties + autism // large, low ears, high palate // macroorchordism (large testes) // hypotonia // mitral valve prolapse

Question 23

diagnosis fragule X

Answer 23

chorionic sampling or amniocentesis

Question 24

genetics noonan

Answer 24

dominant // chromosome 12

Question 25

features noonans

Answer 25

webbed neck, wide nipples, short // pulmonary valve stenosis, ptosis, low set ears, factor XI deficiency

Question 26

symptoms prader willi

Answer 26

hypotonia, hypogonadism, obesity

Question 27

inheritence williams

Answer 27

chromosome 7 microdeletion

Question 28

diagnosis williams

Answer 28

FISH

Question 29

features williams

Answer 29

short // learning difficulties // friendly // transient hypercalcaemia // aortic stenosis

Question 30

genetics homocytinuria

Answer 30

recessive - deficiency cystathione b synathse

Question 31

features homocytinuria

Answer 31

fine hair // marfan like, osteoporosis // learning difficultoes // VTE // malar flush, livido

Question 32

invx homocytinuria

Answer 32

raised homocysteine in serum + urine // cyanide nitroprusside

Question 33

mx homocytinuria

Answer 33

vit B6 (pyridoxine)

Question 34

inheritence Phenylketonuria

Answer 34

recessive

Question 35

features Phenylketonuria

Answer 35

developmental delay at 5 months // fair hair + blue eyes // learning difficulty // seizures // eczema // musty odour

Question 36

diagnosis Phenylketonuria

Answer 36

heel pricj // hyperphenyaemia

Question 37

what are ongogenes

Answer 37

promote cancer

Question 38

how do pro-oncogenes become ongogenes

Answer 38

point mutation, translocation, increased expression

Question 39

oncogene in CLL

Answer 39

ABL

Question 40

oncogene burkitts and neuroblastoma

Answer 40

MYC

Question 41

how do tumour suppresor genes cause cancer

Answer 41

used to suppress cancer –> both stop working

Question 42

examples tumour suppresors

Answer 42

p53, BRCA1+2

Question 43

assoc BRCA1+2

Answer 43

ovarian + prostate