genetics

Question 1

NF-1- AD sporadic mutation.

Answer 1

Cafe au lait patches, axillary freckling, optic glioma, lisch nodules

Question 2

downs (t21)

Answer 2

hypotonia, developmental delay, low IQ, congenital cardia, hypothyroidism , coeliac, leukaemia, A-A instability, vision and hearing

Question 3

Turners (45xo)

Answer 3

short, aortic and renal anomalies, gonadal dysgenesis, infertility, normal IQ, web neck, shield chest

Question 4

Klinefelter 47xxy

Answer 4

eunochoid habitus, gynaecomastia, scant hair, small testes, tall, behavioural phenotype- impulse control, reduced IQ

Question 5

Marfan FBN1

Answer 5

chest deformity, lens dislocation, aortic root dilation

Question 6

Fragile X (CGG triplet repeat on X-Chromosome)

Answer 6

low IQ, behavioural issues, miler in girls

Question 7

Cornelia de Lange

Answer 7

a distinctive facial appearance
prenatal and postnatal growth deficiency
feeding difficulties
psychomotor delay
behavioural problems, and
associated malformations that mainly involve the upper extremities.

Question 8

Williams’ syndrome long arm of chr 7

Answer 8

a distinctive, “elfin” facial appearance
a low nasal bridge, and
an unusually cheerful demeanour and ease with strangers.

Question 9

DiGeorge 22q11. 2 deletion syndrome

Answer 9

Cardiac
Abnormal face
Thymic hypoplasia
Cleft Palate
Hypocalcemia

Question 10

Tay-sachs disease- GM2 buildup

Answer 10

Infants with Tay-Sachs disease appear to develop normally for the first few months of life. Then, as nerve cells become distended with fatty material, a relentless deterioration of mental and physical abilities occurs. “cherry red spots” in eyes

Question 11

Smith-Magenis deletion on chromosome 17

Answer 11

self harm, self hugging

Question 12

Cri Du Chat deletion of the short arm of chromosome 5

Answer 12

hypotonia, short stature, high arched palate, wide bridged nose “cat’s cry”

Question 13

Prader Willi micro-deletion of part of chromosome 15 (85% paternal)

Answer 13

hypotonia, hyperplasia, hypogonadism, intellectual impairment, and challenging behaviours.

Question 14

Angelman micro-deletion of chromosome 15 (maternal)

Answer 14

a happy disposition and laugh frequently for almost any reason and their movements are jerky like those of a marionette, or puppet.

Question 15

Edwards (trisomy 18)

Answer 15

Rocker bottom feet, tightly closed fist at birth with the index finger overlapping the third digit, micrographic and renal abnormalities.

Question 16

Androgen insensitivity syndrome

Answer 16

A person who is genetically male is resistant to androgens. As a result, the person has some of the physical traits of a woman, but the genetic makeup of a man.

Question 17

Pseudohermaphroditism

Answer 17

A person whose gonads are consistent with the chromosomal sex but who has external genitalia of the opposite sex.

Question 18

Adrenogenital syndrome

Answer 18

Deficiency of the adrenocortical enzyme steroid 21-hydroxylase. Symptoms in infants may include ambiguous genitalia in girls and an enlarged penis in boys.

Question 19

Pateau syndrome

Answer 19

Trisomy 13

Question 20

Hungtintons chorea

Answer 20

Trinucleotide repeat on short arm of chromosome 4

Question 21

FTD with Parkinsonism

Answer 21

MAPT gene mutations
(Disrupts tau production and assembly)

Question 22

Triplet coding for one amino acid is altered to one that codes for a different amino acid

Answer 22

Missense Mutation

Question 23

Mutation involving one or two bases

Answer 23

Point mutation

Question 24

Substitution leads to a stop signal so that no mRNA is formed

Answer 24

Nonsense mutation

Question 25

Mutation in the way the mRNA is spliced together

Answer 25

Splice junction mutation

Question 26

No phenotypic consequence

Answer 26

Silent mutation

Question 27

Coding sequence

Answer 27

Exon

Question 28

Rett Syndome

Answer 28

X linked dominant genetic disorder Deceleration of head growth after initially normal growth resulting in significant microcephalic. Progressive cognitive deterioration leading to severe learning disability with gait, apraxia and seizures.

Question 29

Trisomy with greatest risk of AD in adulthood

Answer 29

Down’s syndrome

Question 30

Genetic condition with association with schizophrenia like psychosis

Answer 30

Di George’s/Velo-Cardio facial syndrome

Question 31

A single gene producing variety of defects

Answer 31

Pleiotrophy

Question 32

The exchange of material between two chromosomes

Answer 32

Epistasis

Question 33

Any marker that is heritable and present in a high proportion of families having the disease

Answer 33

Endo phenotype