DIfferences in Sex Development Flashcards
Sex-determining region on the Y presesnce causes what? What if absent?
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
By default humans are what sex?
By default we develop as female unless inhibited by SRY.
What do bipotential gonads mean?
Depending on the signaling, gonads can develop into male or female genitalia
What is Turner syndrome and what causes it?
Monosomy, only 1 X chromosome the ovaries degenerate before birth causing sterility
What are 5 characteristics of Turner syndrome?
Phenotypically male, webbed neck, short stature, normal IQ, impared social cognition
What are 3 associated disorders with Turner syndrome?
Renal problems, hashimotos thyroiditis, cardiac problems
What is Kleinfelter syndrome?
47 XXY - 1 barr body
What are 5 characteristics of Klinefelter syndrome?
Phenotypically female, Slightly lower IQ, learning difficulties, antisocial, criminal behavior, sterility
What is a 46 XY DSD? Genetalia?
They are phenotypically female or intersex but dont look male. Ambiguous or female genetalia, can only be confirmed by karyotype
What are the 3 major categories of 46, XY DSD?
Gonadal dygenesis, impaired androgen synthesis, impared androgen sensitivity
What is complete gonadal dysgenesis?
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
Mutations on what genes can cause Complete Gonadal Dysgenesis?
Steroidogenic factor 1 (SF1) and SOX9 (SRY-box9)
What is 46 XY Impaired hydrogen synthesis?
Genetic mutations effecting genes coding for enzymes that cause a reduction in sythesis of dihydrotestosterone
What is androgen insensitivity syndrome?
Inability of target cells to respond to androgens such as DHT
Where is the Androgen receptor and how is this disease inherited?
Its on the X chromosome and often x-linked recessive if the parent is not completely sterile
What is partial androgen insensitivity syndrome?
Ambiguous genetalia with female or male identity
What is complete androgen insensitivity syndrome?
Female genetalia, no uterus, female gender identity
How do you define a 46 XX DSD?
Genoptypically female but pheontypically male. There is an excess of dihyrotestosterone (DHT)
What are the major categories of 46 XX DSD?
Complete gonadal dysgenesis and androgen excess
What is complete gonadal dygenesis for 46 XX DSD? Can it be passed on?
Male genetalia or ambiguous. Often male identity and seek treatment at puberty. Affected are sterile, cant pass it on
What are the genetic mechanisms for 46 XX DSD complete gonadal dysgenesis? When is it usually noticed?
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.
How do you define a 46 XX DSD Fetal Androgen Excess: Congenital Adrenal Hyperplasia (CAH)? How is it inherited?
There are mutations on the genes coding for steroid metabolism. Recessive inheritance
What deficiency can cause CAH?
21-Hydroxylase deficiency
What is salt wasting classical CAH?
Mutations clock the production of corticoid hormones which shunt steroid precursors into androgen synthesis. Virtually no synthesis of 21-alpha hydroxylase
What are symptoms of Adrenal Crisis (salt wasting CAH)
Hyponatremia, hyperkalemia, arrythmia, manifests in first month of life and is life threataning
What is Simple Virilizing CAH?
Limited production of 21 -alpha hydroxxylase, enough that no salt wasting crisis occurs
In Simple Virilizing CAH, what can elevated levels of androgens cause?
Hirsutism, oligomenorrhea, acne
