Sex Related Herederitery Disorders

Question 1

Hemophilia - what is the hereditary pattern?

Answer 1

XR

Question 2

What is the phenomena that describes the different kinds of hemophilia?
(Factor VIII, XI,IX)

Answer 2

Locus Heterogeneity - multiple genes mutation can each cause similar disorder

Question 3

Duchenne muscular dystrophy - Inheritance patteren ? Outcome?

Answer 3

XR

Death at early age from muscular failure in heart and lungs

Question 4

What is the carrier female phenotype for Duchenne muscular dystrophy?

Answer 4

Mosaic X pattern

Question 5

What are the milder form of the DMD? How does it occur?

DMD involves Frame-shift mutation

Answer 5

Becker Deletion - In-Frame mutation, the sequence missing is shorter
Can live to normal age with walking cane

Question 6

What is the possible therapy options in the future for DMD?

Answer 6

In-Vivo gene editing

Question 7

Adrenoleukodystrophy - What is the pattern of inheritance? Organelle damaged?

Answer 7

X-linked

Defective ABC transporter for Long fatty acids to the peroxisomes - no Beta-Oxidation.

Question 8

Ornithine transcarbamylase deficiency - inheritance? Outcome?

Answer 8

X-linked

Urea cycle enzyme deficiency

Question 9

Androgen Insensitivity syndrome - testosterone receptor mutation.
Inheritance? Phenotype?

Answer 9

X-linked

XY, Males with testicles in the abdomen and female appearance.

Question 10

Kallmann Syndrome - Inheritance? Outcome?

Answer 10

X-linked but also Autosomal Dominant and Autosomal Recessive!
GnRH releasing cells migration from olfactory bulb to hypothalamus - developmental sex problems in each gender.

Question 11

G6PD def. - Inheritance? Outcome? Advantage?

Answer 11

X-linked
Favism- broad bean, aspirin, sulfonamides causing hemolytic jaundice
Malaria resistance

Question 12

Hypophosphatemia - Vitamin D resistant rickets. Inheritance? Outcome?

Answer 12

X-linked, Dominant can effect female also
Phosphate-regulating neutral endopeptidase gene mutation causing deficit in bone mineralization or either kidney reabsorption of phosphate.

Question 13

Fragile X syndrome - Inheritance? Epigenetic modification? Phenotype?

Answer 13

X-linked, dominant so female can be effected as well.
Epigenetic modification - DNA methylation in CpG - blocking of transcription!
Altered neurotransmission causing mental retardation.

Question 14

Rett Syndrome - Inheritance? Phenotype?

Answer 14

XD
MECP2 gene recognizing Methylated CpG is mutated causing elevated amount of heterochromatin - progressive neurodegenerative disorder, eventual mental retardation.

Question 15

Baldness/ Androgenic Alopecia - Inheritance? Sex influence? Enzyme linked to it?

Answer 15

Autosomal Dominant in males but Recessive in females.

In theory associated with 5-alpha reductase that allows DHT, but Androgen receptor is more critical .

Question 16

Precocious Puberty- Inheritance?

Answer 16

Sex limiting cascade - Autosomal Dominant. Steroid hormones are influencing the development. LH receptor mutation.

Question 17

Homoplasmy and Heteroplasmy

Answer 17

Homoplasmy - MtDNA selection is restricting mutated ones from inheritance
Heteroplasmy - MtDNA selection is allowing mutated ones to be inherited

Question 18

Y-Linked inheritance example

Answer 18

SRY gene - Azoospermy is Y-linked but the mutation is always novel not inherited.

Question 19

In DMD what is the consequence of the deletion?

Answer 19

Frame shift Mutation

Question 20

In BMD what is the consequence of the deletion?

Answer 20

In Frame Mutation