W8 - Puberty

Question 1

what is the definition of puberty

Answer 1

the physiological, morphological, and behavioural changes as the gonads switch from infantile to adult forms.

Question 2

what is the definition of the first period a girl has

Answer 2

Menarche

Question 3

what is the definitive sign of puberty in boys

Answer 3

first ejaculation - often nocturnal

Question 4

what 2 hormones are increased at the start of the puberty pathway

Answer 4

FSH and LH

Question 5

what tests would you do to investigate puberty

Answer 5

Pubertal Staging

FSH, LH, Testosterone, Oestradiol, Prolactin, thyroid function, karyotype, Androstenedione, DHEAS

GnRH Test

Bone Age X-ray (dominant hand & wrist)

Pelvic Ultrasound (girls)

Question 6

how much later do boys experience their growth spurt

Answer 6

2 years later than girls

Question 7

what determines the timing of puberty in children

Answer 7

genetics
nutrition
environment

Question 8

what percentage of body fat is needed for menses

Answer 8

17

Question 9

what percentage body fat is needed for ovulation

Answer 9

22

Question 10

what environments cause an earlier puberty

Answer 10

urban area
close to the equator
lower altitude

Question 11

what do ovarian oestrogens for in girls

Answer 11

regulate the growth of breast and female genitalia

Question 12

what do ovarian and adrenal androgens for in girls

Answer 12

control pubic and axillary hair

Question 13

what do testicular androgens do in boys

Answer 13

External genitalia and pubic hair growth
enlargement of larynx and laryngeal muscles - voice deepening

Question 14

what features are first to occur in puberty in boys

Answer 14

testicular enlargement and pubic hair growth

Question 15

when does growth of penis and heigh start

Answer 15

12 months after first start of puberty

Question 16

what is the average age of menarche

Answer 16

13yrs
earlier in ethnic minorities

Question 17

does early puberty result in longer puberty

Answer 17

no
early start, early stop

Question 18

does a late start to puberty mean a late end to puberty

Answer 18

no
more limb growth - are not as tall as expected

Question 19

what is the pathway for FSH and LH release (HPA axis)

Answer 19

Question 20

who and why do some people go into puberty early

Answer 20

Usually girls
Usually idiopathic
CNS lesion may be present

Question 21

what is the aetiology of premature thelarche

Answer 21

isolated breast development
typically very young girls age 1-4y.
Non-progressive, with no growth spurt.
Remits spontaneously.

Question 22

what is the aetiology of Premature Pubarche (Adrenarche)

Answer 22

isolated pubic hair development. Usually girls around 5-7y.

Question 23

what is the aetiology of Isolated Premature Menarche

Answer 23

early onset of periods, despite no, or minimal pubertal development
Exclude hypothyroidism

Question 24

what is the aetiology of Isolated Adolescent Gynaecomastia

Answer 24

common in early to mid-puberty in boys, particularly if obese

Question 25

what is the main cause of central precocious puberty in girls

Answer 25

idiopathic 95%

Question 26

what is central precocious puberty

Answer 26

Congruent breast and pubic hair development Puberty earlier in obese children Associated growth spurt (if short, exclude hypothyroidism) Mood swings Final height may be impaired Pelvic Ultrasound very helpful

Question 27

what would you use the GnRH (LHRH) Test for

Answer 27

to differentiate between true precocious puberty and precocious pseudo-puberty

Question 28

what is the most common cause of central precocious puberty in boys

Answer 28

CNS lesion ALWAYS pathological

Question 29

what is central precocious puberty in boys

Answer 29

Congruent penis and pubic hair development Testicular volumes increased Sexualised behaviour Associated growth spurt Mood swings Final height may be impaired

Question 30

what are some differential causes of true central precocious puberty (GnRH dependent)

Answer 30

Idiopathic precocious puberty CNS tumors Optic glioma associated with NF1 Hypothalamic astrocytoma CNS disorders Developmental abnormalities, hypothalamic harmartoma Encephalitis, Brain abscess Hydrocephalus, Myelomeningocele, Arachnoid cyst Vascular lesion Cranial irradiation Secondary central precocious puberty Psychosocial, i.e. adoption from abroad

Question 31

what are some differential causes of pseudo-precocious puberty (GnRH independent)

Answer 31

Increased androgen secretion Gonadotropin secreting tumours McCune-Albright syndrome Ovarian cyst Oestrogen secreting neoplasm (Hypothyroidism) Iatrogenic or exogenous sex hormones

Question 32

what are some causes of autonomous pseudo-precocious puberty (GnRH independent)

Answer 32

McCune-Albright Syndrome Hormone-Secreting Tumours Autonomous testosterone production (Testotoxicosis) Congenital Adrenal Hyperplasia (boys)

Question 33

what hormone changes would you see in pseudo-precocious puberty (GnRH independent)

Answer 33

High oestradiol or testosterone, with suppressed gonadotrophins.

Question 34

what is McCune-Albright Syndrome

Answer 34

precocious puberty, large irregular café-au-lait polyostotic fibrous dysplasia

Question 35

what kinds of tumours can cause pseudo puberty

Answer 35

Gonadal tumours Adrenal tumours Embryonal tumours Rarely, hCG or TSH secreting tumours

Question 36

what is congenital adrenal hyperplasia

Answer 36

Inborn error of cortisol +/- aldosterone synthesis >95% 21a-hydroxylase deficiency Large amounts of adrenal androgens and testosterone secreted, producing virilisation, but with small testes

Question 37

what is the treatment for congenital adrenal hyperplasia

Answer 37

hydrocortisone replacement

Question 38

what is the treatment for central precocious puberty

Answer 38

GnRH analogues

Question 39

what is the treatment for Gonadotrophin independent precocious puberty

Answer 39

Treat underlying cause Anti-androgens/androgen receptor blockers/aromatase inhibitors

Question 40

what are some common causes of delayed puberty

Answer 40

Constitutional delay in growth & adolescence Illness/malnutrition Failure of Hypothalamus/pituitary Gonadal failure

Question 41

what is the common signs and symptoms of consitutional delay

Answer 41

Often familial Much more common in males (M:F 5:1) Associated short stature Spontaneous puberty will occur Relative disproportion Reduced final height

Question 42

what illnesses can result in delayed puberty

Answer 42

Cystic fibrosis Crohn’s disease Juvenile arthritis Steroid therapy Hypothalamic amenorrhoea - Anorexia Nervosa - Athletes/gymnasts - Due to leptin deficiency

Question 43

what is Hypogonadotrophic Hypogonadism

Answer 43

Hypothalamic GnRH deficiency with Anosmia Kallman’s Syndrome

Question 44

what are the characteristic features of kallmans syndrome

Answer 44

Normal stature Eunuchoid habitus Long limbs Female body shape

Question 45

what sex disturbance would be present in Prader Willi syndrome

Answer 45

Hypogonadotrophic Hypogonadism

Question 46

what are the characteristic features of prader-willi syndrome

Answer 46

Disordered hypothalamic function Short stature Voracious appetite Learning difficulties Characteristic appearance Loss of paternal 15q11

Question 47

what would you see in Pituitary Gonadotrophin deficiency

Answer 47

Hypogonadotrophic Hypogonadism Short stature and other features of hypopituitarism if associated with pituitary pathology May be isolated

Question 48

what sex hormone disfunction is caused in kleinfelters syndrome

Answer 48

Gonadal Failure (47 XXY)

Question 49

what are the features of kleinfelters syndrome

Answer 49

Often mild developmental delay/autistic features Small, hard testes Gynaecomastia (breast ca) Elevated FSH, LH, low testosterone

Question 50

what are the features of turners syndrome

Answer 50

Gonadal failure Characteristic appearance Short stature Cardiac, renal anomalies, glue ear Elevated FSH, LH, low oestradiol