Disorders of Sexual Development

Question 1

The stimulation of growth and genital tubercle and induces fusion of urethral fold and labioscrotal swelling; inhibit growth of vessicovaginal septum preventing the development of vagina is done by what hormone?

Answer 1

DHT

Question 2

What upregulates SOX9 expression?

Answer 2

SRY expression in sertoli cells

Question 3

Mutation in SOX9 can ead to what disease characterisitc of bent limbs?

Answer 3

Campomedial dysplasia

Question 4

What is campomelia dysplasia caused by and what are some characterisitcs?

Answer 4

Chracterized by bowing of long bones, shortened long bones, skeletal dysplaisa, hypoplastic scapulae, narrowed iliac bones, chest hypoplasia - respiratory distress, sex reversal due to gonadal dysgenesis in 46, XY,

Question 5

Regression of mullerian duct needs what gene?

Answer 5

SOX 9 which acts on sertoli call to make AMH

Question 6

intermediate mesoderm requires what factors to form the genital ridge?

Answer 6

Wt1 and SF1

Question 7

Sertoli cells require what factors to produce AMH?

Answer 7

SF1 + SOX9 + WT1 + AMH gene

Question 8

Leydig cells require what gene factor to produce testosterone?

Answer 8

SF1

Question 9

A mutation or deletion of DAX1 results in congenital _

Answer 9

adrenal hypoplasia and hypogonadotripic hypogonadism and testicular development occurs

Question 10

How are genes in the PAR inherited?

Answer 10

inherited in an autosmal fashion. They’re located at the termini of Y chromosomes.

Question 11

Intersex is a possibility in an infant with what two clinical chracteristics in male?

Answer 11

hypospadias

undescended testis

Question 12

In smith-lemli-opitz-syndrome what enzyme is deficient?

Answer 12

7-DHC

Question 13

what are some characterisitics of smith-lemli-opitz syndrome

Answer 13

growth retardation, microcephaly, moderate to severe mental retardation, and multiple major and minor malformations, distinct facial features, cleft palate, cardiac defects, underdevelopped external genitalia in males, postaxial polydactyly, and 2-3 syndactyly of the toes.

Question 14

What are some causes of testosterone synthesis defects?

Answer 14

• impaired Leydig cell differentation
  -enzyme defects in testosterone synthesis
  -defects in adrenal and testicular steroidogenesis
  -STAR deficiency
  -P450 scc deficiency
• 3-beta hydrosteroid dehydrogenase deficiency
  -17a hydroxylase deficiency
  17-b hydroxysteroid dehydrogenase deficiency

Question 15

Defects in what enzymes or their receptors can lead to male with 46, XY, DSD/

Answer 15

17beta HSD

5a-reductase. they’re male with female external genitalia.

Question 16

in 5-a reductase deficiency, females have (normal or abnormal) genitalia; and menarche is (delayed, early, or absent).

Answer 16

normal genitalia and menarche is delayed

Question 17

what are some characteristics of viriization in pregnant female?

Answer 17

• acne
  -low pitch voice
  -clitoral hypertorphy
  child- ambiguous genitalia

Question 18

A type of hypogonadism, 17, XXY but can have other variants like XXXY, XXXXY, XXYY and XXY/mosaics; usually from maternal nondisjunction.

Answer 18

Klinefelter syndrome

Question 19

what are some clinical findings of klinefelter syndrome?

Answer 19

Normal at birth and childhood. Puberty is delayed. As gonadotroins increase, seminiferous tubules do not enlarge; undergo fibrosis and hyalinzaiton leading to small firm testes. they can also have obliterated seminiferous tubules leading to azoospermia. Also presents with small penis, and gynecomastia (High E:T ratio) (functionally abnormal Leydig cells. usually have high levels of FSH and LH postpuberty.

Question 20

What are some clinical presentations of turner syndrome?

Answer 20

• Gonadal dysgenesis
• short stature
• webbed neck (cystic hygroma)
• coarctation of aorta
• high arched palate
• shield-like chest with widely spaced nipples
• short metatarsals
• renal abnormalities
• cubitus valgus
• edema of ahnds and feet
• micrognathia
• lack of ovarian development –> decreased sex steroids
• increased LH/FSH
• decreased estrogen
• increased incidence of diabetes, inflammatory bowel disease, and autoimmune disease

Question 21

What is noonan syndrome?

Answer 21

Male Turner - syndrome

• autosomal dominant
• mutation in PTPN11 gene (about half of cases)
• KRAS-more severe form
• RAF-1 heart problems (hypertrophic cardiomyopathy)

Question 22

What are some clinical characteristics of noonan syndrome?

Answer 22

• delayed puberty
• down-slanting or wide-set eyes
• hearing loss
• low set or abnormally shaped ears
• mild mental retardation (only in about 25% of cases)
• sagging eyelids (ptosis)
• short stature
• small penis
• undescended testicles
• usually chest shape (usually a sunken chest called pectus exacvatum
• webbed and short appear-neck
• fertility problems but fertile