Sex Development 5 Flashcards

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in the following disorders: Kleinfelter syndrome, Turner syndrome, mixed gonadal dysgenesis, 46, XY disorders of gonadal dysgenesis, 5-alpha reductase deficiency, and 21-hydroxylase deficiency.

1
Q

What are the major classifications in disorders of sex development (DSD)?

A
  • Sex chromosome DSD
  • 46, XY DSD
  • 46, XX DSD
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2
Q

What are the major diseases of sex chromosome DSD?

A
  • Kleinfelter Syndrome (47, XXY)
  • Turner Syndrome (45, XO)
  • Mixed Gonadal Dysgenesis (46, XY/45,XO)
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3
Q

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in Kleinfelter syndrome.

A
  • Chromosomal makeup
    • 47 XXY
  • Internal/External genitalia
    • male - testis
      • infancy - may be undescended
      • puberty - starts to increase in size and then fail to continue to grow at small size due to fibrosis
    • gynecomastia - increase in breast tumors
    • tall stature with longer lower legs
  • Abnormalities of genitalia
    • infertility, azoospermia
    • insulin resistance
    • language difficulties and behavioral problems
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4
Q

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in Turner syndrome.

A
  • Chromosomal makeup
    • 50-60%, X monosomy
    • 30% 45, X with mosaicism
    • 5% 46, C with Y chromosome material with structural abnormalities
  • Internal/External genitalia
    • female
  • Abnormalities of the genitalia
    • ovarian dysgenesis (streak gonads)
      • 10-30% have spontaneous pubertal development
      • 5-16% with spontaneous menses
      • 2-8% with spontaneous fertility
      • infertility treatment modalities available, but have significantly increased morbidity and mortality
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5
Q

What are some common physical findings of Turner Syndrome?

A
  • short stature
  • low hairline
  • shield-shaped thorax
  • widely spaced nipples
  • shortened metacarpal
  • small finger nails
  • brown spots (nevi)
  • constriction of aorta
  • elbow defomity
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6
Q

What are some common physiological findings of Turner Syndrome?

A
  • Lymphedema
  • Cardiac malformations
    • coarctation of the aorta
    • bicuspid valve
  • Renal abnormalities
    • horseshoe kidney
    • duplication of renal pelvis
  • Short stature
    • absent SHOX gene
  • Learning disabilities
    • math
    • spatial
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7
Q

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in mixed gonadal dysgenesis.

A
  • Chromosomal makeup
    • 45 XO
    • 46 XY
  • Internal/External genitalia
    • variable
    • leads to highly variable PE findings
  • Abnormalities in the genitalia
    • usually dysgenetic
    • increased risk of tumor formation
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8
Q

What are some common 46 XY DSD?**

A
  • Disorders of Gonadal Development
    • complete or partial gonadal dysgenesis
      • often due to transcription factor abnormalities
    • Ovotesticular DSD
      • ovotestis
      • ovary on one side and testis on another
      • ambiguous genitalia
  • Disorders of Androgen Synthesis or Action
    • LH receptor mutations
    • forms of congenital adrenal hyperplasia
    • complete or partial androgen insensitivity
    • 5-alpha reductase deficiency
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9
Q

What are the main features of complete androgen insensitivity syndrome?**

A
  • 46, XY
  • Mutation in androgen receptor (AR) gene
  • Characteristics
    • testes
    • female external genitalia
    • absence of mullerian duct derivatives
    • sparse sexual hair
    • spontaneous pubertal breast development
      • aromatization of androgens to estrogens
  • Presentation
    • inguinal/labial masses
    • amenorrhea
  • Raised female
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10
Q

What are the main features of partial androgen insensitivity syndrome?**

A
  • 46, XY
  • Mutation in androgen receptor, but still partially responsive to androgen
  • Presentation
    • infancy with ambiguous genitalia
  • Characteristics
    • testes
    • absent mullerian structures
    • wolffian ducts abnormal
    • undervirilized external genitalia
  • Puberty
    • enlargement of phallus
    • usually still small
  • Raise as male or female (?)
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11
Q

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in 5-alpha reductase deficiency.

A
  • Chromosomal makeup
    • 46, XY
  • Internal/External genitalia
    • impaired conversion of testosterone to DHT
    • undervirilization
      • testes
      • differentiation of wolffians tructures
      • absence of mullerian derived structures
      • small phallus
      • urogenital sinus with perineal hypospadias
      • blind vasinal pouch raise
  • Abnormalities of genitalia
    • at puberty, progressive virilization
      • muscular development
      • voice change
      • phallic enlargement
      • scanty facial hair
      • small prostate
      • low fertility
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12
Q

What are the major 46, XX DSD?

A
  • Disorders of gonadal development
    • testicular DSD
      • translocation of SRY onto X chromosome
      • gonads - normal testicles
      • male internal and external genitalia
    • ovotesticular DSD
    • Transcription factor abnormalities
  • Disorders of androgen synthesis
    • maternal virilizing tumors
    • congenital adrenal hyperplasia (CAH)
      • 21 hydroxylase deficiency
      • 11 hydroxylase deficiency
    • Placental aromatase deficiency
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13
Q

Describe the chromosomal makeup, external and internal genitalia, and abnormalities of the genitalia in 21 hydroxylase deficiency.

A
  • Chromosomal makeup
    • homozygous or compound heterozygous mutations
    • 46, XX
    • 46, XY
    • types
      • classical salt wasting (more common)
      • simple virilizing
  • Internal/External genitalia
    • ovaries
    • female internally
    • variable ambiguity externally
  • Abnormalities of the genitalia
    • classic form
      • presents in infancy
      • ambiguous genitalia and salt-wasting
      • replace cortisol and aldosterone
    • non-classic form
      • presents later in life
      • mild virilization
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