PAEDS 203 - Puberty and Adolescence

Question 1

What is consonance (in puberty)?

Answer 1

Smooth ordered progression of changes that happen throughout puberty in a somewhat uniform way

Question 2

What does non-consonance in puberty suggest?

Answer 2

Over-activity of the sex hormones peripherally and usually present with virilizartion

Question 3

What age does puberty occur in males and females?

Answer 3

males 10-11

females 8-9

Question 4

How does puberty start?

Answer 4

Pulsatile release of GnRH which stimulates LH and FSH secretion from the anterior pituitary

Question 5

What actions does LH have in the male and female?

Answer 5

Male: acts on Leydig cells to stimulate testosterone production
Female: acts on Theca cells to stimulate androgen production

Question 6

What actions does FSH have in the male and female?

Answer 6

Male: stimulates Sertoli cells in the seminiferous tubules to produce mature spermatozoa
Female: stimulates follicular development and aromatase activity by acting on granulosa cells (therefore oestrogen production)

Question 7

What are the main consequences of testosterone in male puberty?

Answer 7

Development of male secondary sexual characteristics : axilliary and pubic hair, enlargement of external genitalia, deepening voice, sebum secretion, muscle growth, libid and spermatogenesis

Question 8

What are the main consequences of oestrogen in female puberty?

Answer 8

Breast and nipple development, vaginal and vulval growth, pubic hair, growth and maturation of uterus and fallopian tubes

Question 9

What is the order of consonance for puberty in girls?

Answer 9

breast development, pubic hair, growth spurt, axillary hair

Question 10

What is the order of consonance for puberty in boys?

Answer 10

Testicular/scrotal growth, pubic hair, growth spurt, increase in penis size, voice change, facial/axillary hair

Question 11

How much do girls and boys grow approximately in puberty? What accounts for boys being taller than girls?

Answer 11

Boys 28cm Girls 25cm

Boys have an extra two years of growth as a child before puberty

Question 12

What finishes bone growth?

Answer 12

Oestrogen causing fusion of epiphyseal plates

Question 13

What defines delayed puberty?

Answer 13

Complete absence of physical signs of puberty after age 13 in girls and age 14 in boys

Question 14

What are the two divisions that causes of delayed puberty can be split into?

Answer 14

Primary gonadal failure = hypergonadotrophic (high FSH and LH) and central failure = hypogonadotrophic (low FSH and LH)

Question 15

What are some of the causes of primary gonadal failure ?

Answer 15

Turners syndrome
Klinefelters syndrome
Androgen insensitivity syndrome
5 alpha reductase deficiency
Pelvic radiotherapy or chemotherapy

Question 16

Describe Turners syndrome?

Answer 16

Often first manifestation in short stature and primary ammenorhoea - infertility or subfertility
Results from an XO chromosome but can have moasicism
Associated with diabetes, congenital heart defects, neck webbing and renal malformations

Question 17

Describe Klinefelters syndrome?

Answer 17

XXY chromosomes and also have varying degrees of severity due to different mosaicisms.
Many men go undiagnosed until present with infertility later in life. In childhood there may be unusual rapid growth and failure of sexual maturation
Small firm tests and gynaecomastia
Treat with testosterone treatment during puberty

Question 18

Describe androgen insensitivity syndrome

Answer 18

X linked recessive condition leading to failure of normal masculinization of the external genitalia in genetically male patient. Insufficient post receptor response after androgen stimulation. Can be complete or partial leading to a spectrum of presentations: infertility, gynaecomastia, vagina and clitoris or just clitomegaly or hypospadias

Question 19

Describe 5 alpha reductase deficiency

Answer 19

AR sex limited condition
Inability to convert testosterone to DHT
therefore may be more with ambiguous genitalia and cryptorchidism

Question 20

What are some of the causes of central failure in delayed puberty?

Answer 20

Constitutional
Anorexia
Excessive excersize
Hypothyroidoism
Intracranial tumour
Isolated GH or GnRH deficiency

Question 21

Define precocious puberty

Answer 21

Onset of secondary sexual characteristics in less than 8 in girls and less than 9 in boys

Question 22

How do you manage precocious puberty?

Answer 22

Check bone age and pelvic structures (usually advanced by +2years)
MRI the pituitary
Treat with GnRH analogue until puberty should begin at about 11/12

Question 23

What are the two divisions of classifying precocious puberty?

Answer 23

True central - gonadotrophin dependant

Peripheral - gonadotrophin independant

Question 24

What are some of the causes of true central precocious puberty?

Answer 24

Most commonly idiopathic (more common in obese children and females)
Tumours
hydrocephalus
chronic inflammatory disease
Trauma, abuse or adoption

Question 25

What tests distinguish between central, gonadotrophin dependant puberty and peripheral, gonadotrophin-independant puberty?

Answer 25

In central: LH and FSH and oestrogen are detectable and there is a positive response to the LHRH test
In peripheral: undetectable LH and FSH, with no LHRH response but detectable sex hormones

Question 26

What are some of the causes of precocious puberty?

Answer 26

Ovarian cysts, 
cushings syndrome
, adrenal tumours, 
congenital adrenal hyperplasia
McCune albright syndrome
Testotoxicosis

Question 27

What is premature thelarche?

Answer 27

Early breast development but no other precocious features

Question 28

What is exaggerated adrenarche?

Answer 28

Early pubic hair, body odour, mild acne but no other precocious features due to early adrenarche

Question 29

Describe congenital adrenal hyperplasia

Answer 29

Group of AR disorders that involve an enzyme deficiency in the synthesis of cortisol and/or aldosterone
Clinical phenotype depends on enzyme deficiency and severity but females present with: virilisation, milder: early puberty
Males present normally but severe: salt wasting and failure to thrive, milder - early puberty
Treat symptoms and llong term glucocorticoid

Question 30

Describe the presentation of McCune Albright Syndrome

Answer 30

Cafe au lait patches unilaterally, bone changes due to polyostotic fibrous dysplasia and often early puberty and hyperthyroidism (endocrine abnormalities)

Question 31

Describe testotoxicosis

Answer 31

Actvating mutation of LHreceptor gene therefore increased sex steroids produced and decreased LH

Question 32

What do bipotential gonads contain?

Answer 32

Both mullerian and wolffian ducts

Question 33

What stimulates differentiation into male gonads?

Answer 33

Presence of SRY gene

Question 34

What does the SRY protein stimulate?

Answer 34

Sertoli cells - produce AMH

Leydig cells - produce testosterone

Question 35

What is the action of AMH?

Answer 35

Stimulates a wave of apoptosis causes the mullerian duct to regress and the wolffian duct to form the urinary tract and internal male genital structures

Question 36

What causes external male genital formation?

Answer 36

DHT - converted in penile skin from testosterone via 5 alpha reductase

Question 37

What happens in the absence of the SRY gene?

Answer 37

Mullerian ducts form uterine tubes, uterus and upper third of vagina and the lack of androgens allows the vagina, labia and clitoris to form

Question 38

What is the mullerian duct also known as?

Answer 38

The paramesonephric duct

Question 39

What is the wolffian duct also known as?

Answer 39

The mesonephric duct