Growth/ Endocrine

Question 1

Mechanism of T2DM

Answer 1

Insulin resistance followed by B cell failure

Question 2

Mechanism of T1DM

Answer 2

Autoimmune damage to pancreatic B cells, leading to insulin deficiency

Question 3

What are the markers to B cell destruction?

Answer 3

Islet cell antibodies Antibodies to glutamic acid decarboxylase

Question 4

S+S DM

Answer 4

Polydipsia Polyuria Weight loss

Question 5

S+S DKA

Answer 5

Vomiting Dehydration Abdo pain Hyperventilation due to acidosis (Kussmaul breathing) Hypovolaemic shock Drowsiness

Question 6

What glucose results would indicate DM?

Answer 6

Random BM >11.1 Fasting BM >7

Question 7

Types of insulin with onset of action, peak + duration, + when to give

Answer 7

Short acting human regular: 30-60 min action, peak 2-4 hours, 8hr duration, give 15-30 mins before meals Immediate acting: onset 1-2hrs, peak 4-12hrs

Question 8

What is a basal bolus regime?

Answer 8

3-4 times a day Short acting insulin (bolus) before meals + long acting insulin before bed (basal)

Question 9

S+S hypoglycaemia

Answer 9

Symptoms occur below 4 Hunger, abdo pain, sweatiness, fainting, seizures, irritability

Question 10

What is mild vs severe FTT?

Answer 10

Mild = fall across 2 centiles Severe = fall across 3 centiles

Question 11

What makes males genitalia?

Answer 11

Testis determining gene on Y chromosome (SRY) Production of testosterone produces male genitalia

Question 12

Reasons for ambiguous genitalia at birth

Answer 12

Excess androgens causing growth of female genitals = congenital adrenal hyperplasia Inadequate androgen production in males = inability to respond to androgens or inadequate synthesis from cholesterol

Question 13

How to determine sex

Answer 13

Karyotyping Adrenal + sex hormones measured USS of internal structures

Question 14

Pathology of congenital adrenal hyperplasia

Answer 14

Autosomal recessive disorder Common in consanginous couples Cortisol deficiency stimulates pituitary to produce ACTH, driving production of androgens

Question 15

Presentation of congenital adrenal hyperplasia

Answer 15

Virilisation of female genitals = clitoral hypertrophy, fusion of labia Enlarged penis + pigmented scrotum Salt-loosing adrenal crisis at 1-3 weeks (vomiting, ewight loss, floppiness) Precocious puberty

Question 16

Diagnosis of congenital adrenal hyperplasia

Answer 16

Made by finding raised precursor 17α-hydroxyprogesterone in blood In salt losers: Metabolic acidosis Hypoglycaemia

Question 17

Management of ambiguous genitalia

Answer 17

Corrective surgery Males in salt-losing crisis need saline, dextrose + hydrocortisone IV Long term glucocorticoids to suppress ACTH Mineralcorticoids if there is salt loss

Question 18

What is classed as precocious puberty?

Answer 18

Development of secondary sexual characteristics before 8 in females + 9 in males

Question 19

Causes of precocious puberty

Answer 19

Growth spurts Breast development (thelarche) Pubic hair devleopment (pubarche) Intracranial tumours, hydrocephalus, menigitis

Question 20

What is true vs pseudo precocious puberty?

Answer 20

True = gonadotrophin dependant - from premature activation of HPG axis Pseudo - from excess sex steroids

Question 21

Is precocious puberty common in males or females?

Answer 21

Common in females - likely to have enlarged uterus + polycystic ovaries Uncommon in males, usually has an organic cause

Question 22

How can examining testes in males help identify cause of precocious puberty?

Answer 22

Bilateral enlargement = gonadotrophin release, usually due to intracranial lesions Small testes = adrenal cause (tumour or hyperplasia) Unilateral enlarged testes = gonadal tumour

Question 23

What is the definition of delayed puberty?

Answer 23

Absence of pubertal development by 14 in girls + 15 in boys

Question 24

Causes of delayed puberty

Answer 24

Constitutional delay of growth

Low gonadotrophin secretion due to CF, asthma, Crohns, anorexia, HPG disorders

High gonadotrophin secretion (chromosomal abnormalities, steroid hormone deficiency, gonadal damage)

Question 25

Management of delayed puberty

Answer 25

Oral oxandrolone in young males, testosterone in older males Oestrodiol in females

Question 26

Normal thyroxine production in infants

Answer 26

Fetal thyroid produces reverse T3 (inactive) Surge in TSH after birth, causes raised T3 + T4 levels TSH declines to normal in first week

Question 27

What is juvenile hypothyroidism?

Answer 27

Commoner in females Growth failure accompanied by delayed bone age Goitre present

Question 28

Congenital hypothyroidism causes?

Answer 28

Absence of thyroid Small thyroid Maldescent of thyroid

Question 29

S+S of congenital hypothyroidism

Answer 29

Usually asymptomatic FTT, feeding problems, prolonged jaundice Constipation Umbilical hernia

Question 30

S+S of acquired hypothyroidism

Answer 30

Short stature Cold intolerance Dry skin Bradycardia Thin hair Goitre Constipation

Question 31

Management of hypothyroidism

Answer 31

Oral thyroxine

Question 32

What is phenylketonuria?

Answer 32

Type 1: autosomal recessive genetic disorder Deficiency of enzyme which converts phenylalanine to tyrosine High conc is neurotoxic Type 2: cases of hyperphenylalaninaemia Malignant PKU = deficiency in THB (enzyme co factor

Question 33

S+S phenylketonuria

Answer 33

Delayed development, poor growth, seizures

Develops at 6-12 months

Recurrent vomiting

Behavioural disturbances

Older children: hyperactive, rhythmic rocking, writhing movements

Question 34

Investigations for phenylketonuria

Answer 34

Guithre test

Question 35

Management of phenylketonuria

Answer 35

Low phenylalanine diet: no meat, cheese, poultry, egg, milk

Question 36

What are the causes of short stature?

Answer 36

Familial IUGR Constitutional delay Hypothyroidism Growth hormone deficiency Corticosteroid excess, Cushings Nutritional/ chronic illness Chromosomal disorders