DIfferences in Sex Development

Question 1

Sex-determining region on the Y presesnce causes what? What if absent?

Answer 1

If it is present it is expressed in sertoli cells that surround and support spermatogenic cells of the testes and leads to the differentiation of Leydig cells which produce testosterone. IF absent, gonads become ovaries

Question 2

By default humans are what sex?

Answer 2

By default we develop as female unless inhibited by SRY.

Question 3

What do bipotential gonads mean?

Answer 3

Depending on the signaling, gonads can develop into male or female genitalia

Question 4

What is Turner syndrome and what causes it?

Answer 4

Monosomy, only 1 X chromosome the ovaries degenerate before birth causing sterility

Question 5

What are 5 characteristics of Turner syndrome?

Answer 5

Phenotypically male, webbed neck, short stature, normal IQ, impared social cognition

Question 6

What are 3 associated disorders with Turner syndrome?

Answer 6

Renal problems, hashimotos thyroiditis, cardiac problems

Question 7

What is Kleinfelter syndrome?

Answer 7

47 XXY - 1 barr body

Question 8

What are 5 characteristics of Klinefelter syndrome?

Answer 8

Phenotypically female, Slightly lower IQ, learning difficulties, antisocial, criminal behavior, sterility

Question 9

What is a 46 XY DSD? Genetalia?

Answer 9

They are phenotypically female or intersex but dont look male. Ambiguous or female genetalia, can only be confirmed by karyotype

Question 10

What are the 3 major categories of 46, XY DSD?

Answer 10

Gonadal dygenesis, impaired androgen synthesis, impared androgen sensitivity

Question 11

What is complete gonadal dysgenesis?

Answer 11

AKA Sawyer syndrome - Impaired development of leydig and/or sertoli cells. The appear female with a normal uterus and fallopian tube. Gonadal streak instead of developed ovaries

Question 12

Mutations on what genes can cause Complete Gonadal Dysgenesis?

Answer 12

Steroidogenic factor 1 (SF1) and SOX9 (SRY-box9)

Question 13

What is 46 XY Impaired hydrogen synthesis?

Answer 13

Genetic mutations effecting genes coding for enzymes that cause a reduction in sythesis of dihydrotestosterone

Question 14

What is androgen insensitivity syndrome?

Answer 14

Inability of target cells to respond to androgens such as DHT

Question 15

Where is the Androgen receptor and how is this disease inherited?

Answer 15

Its on the X chromosome and often x-linked recessive if the parent is not completely sterile

Question 16

What is partial androgen insensitivity syndrome?

Answer 16

Ambiguous genetalia with female or male identity

Question 17

What is complete androgen insensitivity syndrome?

Answer 17

Female genetalia, no uterus, female gender identity

Question 18

How do you define a 46 XX DSD?

Answer 18

Genoptypically female but pheontypically male. There is an excess of dihyrotestosterone (DHT)

Question 19

What are the major categories of 46 XX DSD?

Answer 19

Complete gonadal dysgenesis and androgen excess

Question 20

What is complete gonadal dygenesis for 46 XX DSD? Can it be passed on?

Answer 20

Male genetalia or ambiguous. Often male identity and seek treatment at puberty. Affected are sterile, cant pass it on

Question 21

What are the genetic mechanisms for 46 XX DSD complete gonadal dysgenesis? When is it usually noticed?

Answer 21

Translocation of the SRY (80%)- The fathers x chromosome is inherited and has SRY or SRY-negative (20%) _ duplication of SOX 9 and more likelt to cause ambiguous genetalia. Usually noticed at puberty due to lack of secondary sexual characteristics.

Question 22

How do you define a 46 XX DSD Fetal Androgen Excess: Congenital Adrenal Hyperplasia (CAH)? How is it inherited?

Answer 22

There are mutations on the genes coding for steroid metabolism. Recessive inheritance

Question 23

What deficiency can cause CAH?

Answer 23

21-Hydroxylase deficiency

Question 24

What is salt wasting classical CAH?

Answer 24

Mutations clock the production of corticoid hormones which shunt steroid precursors into androgen synthesis. Virtually no synthesis of 21-alpha hydroxylase

Question 25

What are symptoms of Adrenal Crisis (salt wasting CAH)

Answer 25

Hyponatremia, hyperkalemia, arrythmia, manifests in first month of life and is life threataning

Question 26

What is Simple Virilizing CAH?

Answer 26

Limited production of 21 -alpha hydroxxylase, enough that no salt wasting crisis occurs

Question 27

In Simple Virilizing CAH, what can elevated levels of androgens cause?

Answer 27

Hirsutism, oligomenorrhea, acne