Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Repro > Disorders Of Sexual Development > Flashcards

Disorders Of Sexual Development Flashcards

1
Q

At week 5, medioventral border of urogenital ridge thickens to become __

A

Gonadal ridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

At week 6, primordial germ cells are incorporated into __

A

Primary sex cords

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When is sex indistinguishable in the fetus?

A

before week 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When does development begin in male vs female?

A

Male: testis organization begins in weeks 6 and 7
Female: begins week 12
External genitalia of both sexes identical up to about week 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does DHT do for male development?

A

Stimulates growth of genital tubercle and induces fusion of urethral folds and labioscrotal swellings
Inhibits growth of vesicovaginal septum preventing development of vagina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the SRY gene

A

One exon
GC-rich in 5’ region
2 zinc-finger rich recognition sites for Sp1
Has HMG motif (conserved protein sequence that participates in transcription, replication, recombination, and repair. Induces conformational change for other factors to bind and direct transportation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens if there are HMG octamer mutations in SRY gene?

A

No binding to DNA
No male differentiation
46 XY female

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe steroidogenic factor 1

A

Required for SRY expression
Gonads and adrenal development require SF1
Required for sexual determination, sexual differentiation, steroidogenesis, and lipid metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is required for SRY expression, gonad and adrenal development, sexual determination, sexual differentiation, steroidogenesis, and lipid metabolism?

A

Steroidogenic factor 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What upregulates SOX9 expression?

A

SRY expression in Sertoli cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does SRY expression in Sertoli cells upregulate?

A

SOX9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does a mutation in SOX9 lead to?

A

Camptomelia dysplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Camptomelia dysplasia results from a mutation in what gene?

A

SOX9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the clinical manifestations of campomelia dysplasia

A 
Bowing of long bones
Shortened long bones
Skeletal dysplasia (hypoplastic scapulae, narrowed iliac bones, chest hypoplasia with respiratory distress)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What disorder is characterized by bowing of long bones, shortened long bones, hypoplastic scapulae, narrowed iliac bones, chest hypoplasia with respiratory distress?

A

Campomelia dysplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe mechanism behind campomelia dysplasia

A

Associated with sex reversal due to gonadal dysgenesis in 46 XY
No SOX9 -> Mullerian ducts do not degenerate so ovary develpment occurs
AMH diffuses from Sertoli cells to paired Mullerian duct primordia
AMH attaches to receptors (serine-threonine protein kinases - single transmembrane domain)
Apoptosis occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is associated with sex reversal due to gonadal dysgenesis in and persistence of Mullerian ducts in 46 XY?

A

Campomelia dysplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe DAX1 gene (dosage sensitive sex reversal - adrenal sensitive sex reversal on X chromosome)

A

DAX1 is normally down-regulated by SRY in developing testes but not in ovary
DAX1 blocks AMH upregulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does mutation or deletion of DAX1 result in?

A

Congenital adrenal hypoplasia and hypogonadotropic hypogonadism
Duplication in males -> 46 XY females
Duplication in females -> no effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What mutations can cause sex reversal?

A

SRY mutations: 46 XY females; 46 XX males with SRY translocated to X
SOX9 mutations
DAX1 duplication

21
Q

Describe hypospadias

A

Abnormality of anterior urethral development in which urethral opening is ectopically located on ventrum of penis proximal to tip of glans penis.
May have associated ventral shortening and curvature (chordee)

22
Q

What is the Smith-Lemli-Opitz syndrome?

A

Congenital multiple anomaly syndrome caused by an abnormality in cholesterol metabolism resulting from deficiency of enzyme 7-dehydrocholesterol (7-DHC) reductase

23
Q

What is the congenital multiple anomaly syndrome caused by deficiency in 7-dehydrochlesterol (7-DHC) reductase?

A

Smith-Lemli-Opitz syndrome

24
Q

Describe the characteristics and malformations of Smith-Lemli-Opitz syndrome

A

Prenatal and postnatal growth retardation, microcephaly, moderate to severe mental retardation
Distinctive facial features, cleft palate, cardiac defects, underdeveloped external genitalia in males, postaxial polydactyly, and 2-3 syndactyly of toes

25
Q

What syndrome is characterized by prenatal and postnatal growth retardation, microcephaly, moderate to severe mental retardation, cleft palate, cardiac defects, underdeveloped external male genitalia, postaxial polydactyly, and 2-3 syndactyly of toes? What is the defect?

A

Smith-Lemli-Opitz syndrome

7-dehydrocholesterol reductase

26
Q

What are causes of testosterone synthesis defects?

A

Impaired Leydig cell differentiation
Enzyme defects in testosterone synthesis
Defects in adrenal and testicular steroidogenesis
STAR deficiency
P450scc deficiency
3beta hydroxysteroid dehydrogenase deficiency
17alpha hydroxylase deficiency
17beta hydroxysteroid dehydrogenase deficiency

27
Q

What is a cause of testosterone metabolism defects?

A

5alpha reductase deficiency

28
Q

Describe androgen insensitivity syndrome (defect in androgen action)

A 
XY sex chromosomes
Female body shape
Enlarged breasts with juvenile nipples
Absent or scanty axillary or pubic hair
Female external genitalia with small labia
Blind-ending vagina
Absent or rudimentary internal genitalia
Cryptorchisdism
Normal male testosterone levels
Testes produce androgens and estrogen
Eleveated FSH, LH, hCG
No male pattern baldness
29
Q

What syndrome is characterized by XY, normal male testosterone levels, elevated FSH, LH, hCG, female body shape, enlarged breasts with juvenile nipples, absent or scanty axillary or pubic hair, female external genitalia with small labia, blind-ending vagina, cryptorchidism?

A

Androgen insensitivity syndrome

30
Q

What causes persistence of Mullerian ducts syndrome?

A

Defect in AMH synthesis

Defect in AMH receptor

31
Q

What causes congenital non-genetic 46 XY DSD?

A

Maternal intake of endocrine disuptors:

BPA, phthalates, parabens, PBDE, PCB, dioxin, pesticides/herbicides, heavy metals

32
Q

Describe ovotesticular DSD

A

Both ovarian and testicular tissue in one or both gonads
Internal and external differentiation is variable (often ambiguous, cryptochidism common, hypospadias common)
Ovotestis is the most common gonad found

33
Q

Describe 17beta-hydroxysteroid dehydrogenase deficiency

A

46 XY with female external genitalia
Testes and Wolffian derivatives
At puberty - virilization
Deepening voice, clitoral enlargement, hirsutism, male muscularity, breast development

34
Q

What disorder is characterized by 46 XY with female external genitalia, testes and Wolffian derivatives, and virilization at puberty (clitoral enlargement, hirsutism, male muscularity, breast development)?

A

17beta-hydroxysteroid dehydrogenase deficiency

35
Q

Describe 5alpha reductase deficiency?

A

Deficient conversion of testosterone to DHT, so deficient DHT binding to androgen receptor
External genitalia appear female at birth
Testes extra-abdominal, usually inguinal
Hypospaid microphallus
Blind vaginal pouch
Normal blood testosterone but elevated T:DHT ratio

36
Q

What disorder is characterized by deficient conversion of testosterone to DHT, normal blood testosterone but elevated T:DHT ratio, external genitalia that appears female at birth, extra-abdominal testes, hypospadic microphallus, and blind vaginal pouch?

A

5alpha reductase deficiency

37
Q

What happens with excess androgen?

A

Masculinize external genitalia during female development
Prematurely virilize external genitalia of affected male
Virilize woman during pregnancy of affected child

38
Q

What occurs with virilization in pregnant female?

A

Acne
Low pitch voice
Clitoral hypertrophy
Child -> ambiguous genitalia

39
Q

Describe Klinefelter syndrome

A

47 XXY
Puberty may be delayed
Seminiferous tubules do not enlarge, instead undergo fibrosis and hyalinization -> small, firm testes
Obliterated seminiferous tubules -> azoospermia
Functionally abnormal Leydig cells -> secrete estradiol and increase LH
Testosterone decreased
High E:T ratio responsible for feminization and gynecomastia
FSH also high
Abnormal skeletal proportions: LS>US
Mental retardation
Dissocial behavior
Increased risk for autoimmune disorders (diabetes)

40
Q

What is characterized by small and firm testes, obliterated seminiferous tubules, abnormal Leydig cells, high LH and FSH, high E:T ratio, gynecomastia, abnormal skeletal proportions, retardation, dissocial behavior, and increased risk for autoimmune disorders?

A

Klinefelter syndrome

41
Q

Describe Turner syndrome

A 
45X
Normal intelligence
Gonadal dysgenesis
Short stature
Webbed neck
Coarctation of aorta
High arched palate
Shield-like chest with widely spaced nipples
Short metatarsals
Renal abnormalities 
Cubitus valgus
Edema of hands and feet 
Micrognathia
42
Q

What syndrome is characterized by 45X, normal intelligence, gonadal dysgenesis, short stature, webbed neck, coarctation of aorta, high arched palate, shield-like chest with widely spaced nipples, short metatarsals, renal abnormalities, cubitus valgus, edema of hands and feet, and micrognathia?

A

Turner syndrome

43
Q

Describe the hormones of Turner syndrome

A

Lack of ovarian development leads to deficient secretion of sex steroids
Elevated LH/FSH
Decreased estrogen

44
Q

Describe Noonan syndrome

A 
"Male Turner" syndrome
Autosomal dominant
Mutations in PTPN11 gene
KRAS - more severe form
RAF1 - heart problems (hypertrophic cardiomyopathy)
45
Q

What syndrome is caused by mutations in PTPN11 gene, and KRAS or RAF1?

A

Noonan syndrome

46
Q

What are the characteristics of Noonan syndrome?

A 
Delayed puberty
Down-slanting or wide-set eyes
Hearing loss
Low-set or abnormally shaped ears
Mild mental retardation
Pulmonary stenosis
Short stature
Sagging eyelids (ptosis)
Small penis
Undescended testicles
Unusual chest shape (sunken chest called pectus excavatum)
Webbed and short-appearing neck
Fertility problems but fertile
47
Q

What syndrome has the characteristics of sagging eyelids (ptosis), short stature, webbed and short-appearing nect, pectus excavatum, small penis, undescended testes, delayed puberty, down-slanting eyes, hearing loss, low-set ears, mild mental retardation, pulmonary stenosis?

A

Noonan syndrome

48
Q

At week 4, primordial germ cells are recognizable in yolk sac wall, go through mitosis and migrate through ___

A

Dorsal mesentery of hindgut

Repro (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions