Diseases

Question 1

Leber’s Hereditary Optic Neuropathy (LHON)

Answer 1

Mitochondrial Inheritance

Degeneration of Retinal Ganglion cells

Caused by mtDNA impacting NADH dehydrogenase (loss of vision)

Loss of vision

Question 2

Myoclonic Epilepsy and Raged Red Fibers (MERRF)

Answer 2

Mitochondrial Related disease

Mutation in tRNA for lysine

Disrupts synthesis of cyt-c (Complex 4)

Myoclonus & ataxia

Question 3

Mitochondrial Encephalomyopathy, Lactic Episodes, and stroke-like episodes (MELAS)

Answer 3

Mitochondrial related disease (complex 1 and 4)

For leucine mutation

Most common

Affects many body systems

Stroke + dementia

Diabetes, deafness, cognitive impairment

Question 4

Postaxial Polydactyly

Answer 4

Autosomal Dominant Inheritance

Webbed Fingers/Extra fingers

Question 5

Tyrosinase-Negative Albinism

Answer 5

Autosomal Recessive Inheritance

Loss of pigment

Question 6

Duchenne Muscular Dystrophy

Answer 6

X-linked Recessive

Absence of defective dystrophin

Death by mid-20s

Question 7

Hypophosphatemia

Answer 7

X-linked Dominant

Question 8

Polyploidy

Answer 8

Cells contain complete set of extra chromosome

Common in plants

Question 9

Aneuploidy

Answer 9

Cells contain missing or extra chromosome

Question 10

Prader-Willi Syndrome

Answer 10

Caused by Genetic imprinting of Chromosome 15

Maternal Disomy or Paternal Deletion

Obesity, short stature, mild intellectual disability

Question 11

Angelman Syndrome

Answer 11

Caused by Genetic Imprinting of Chromosome 15

Maternal Deletion or Paternal Disomy

Severe Intellectual disability, seizures, ataxic gait

Question 12

Turner Syndrome

Answer 12

45, XO karyotype

Short stature, underdeveloped female reproductive parts, 30% webbed neck, no cognitive defects

Question 13

Klinefelter Syndrome

Answer 13

47, XXY

Male but with extra feminized traits:
Breast development, hypogonadism, infertility, tall stature

The more X chromosomes, the worse the conditions

Question 14

Downs Syndrome

Answer 14

Trisomy 21 (47, XX + 21)

Most common (1/700)

Question 15

Edward’s Syndrome

Answer 15

Trisomy 18 (47, XX + 18)

1/6000
95% in Utero death, Microencephaly, malformed, low-set ears, cleft-lip, overlapped fingers

Question 16

Patau’s Syndrome

Answer 16

Trisomy 13 (47, XX + 13)

Severe developmental abnormalities

1/12 500

CNS dysfunction, really bad

Question 17

Retinoblastoma

Answer 17

Autosomal Dominant

Penetrance is 90%

Cancer starts in eyes, moves to brain

Question 18

Neurofibramatosis

Answer 18

Tumor like growths on skin
“cafe-au-lait” spots

Example of Variable Expressivity

Question 19

Marfan Syndrome

Answer 19

Connective tissue disorder

Characterized by long limbs, ectopia lens, weak aorta

Example of Variable Expressivity

Question 20

Osteogenesis Imperfecta

Answer 20

Brittle Bone Disease

Mutation in collagen loci: Chromosome 7, 17

Question 21

Cystic fibrosis

Answer 21

Autosomal Recessive

Question 22

Pyloric Stenosis

Answer 22

Muscular hypertrophy between stomach and duodenum
Vommiting, obstruction etc

Example of Multifactorial Inheritance;
Males more impacted, need less risk genes to show