Endocrine Flashcards
Prolactin inhibitory hormone
Dopamine
Most reliable vitamin D test
25-hydroxyvitamin D
adrenal insufficiency
ACTH elevated if primary cortisol def
Investigate with synacthen test
Adjusted na equation in DKA
Na + 0.3(glucose-5.5)
Serum osmolality equation
2xNa + glu
Leydig cells secrete
SRY gene develop leydig cells which secrete testosterone
Sertoli cells secrete
AMH
> 90% CAH from
21-hydroxylase def
High 17-hydroxyprogesterone
(70% aldosterone and cortisol def)
Hypothalamic hamartoma clinically
Precocious puberty
DI
Gelastic sz (laughing or crying)
McCune Albright clinically (triad and other)
Classic triad:
Precocious puberty (peripheral) endo gain of function
Polyostotic Fibrous dysplasia
Cafe au lait (rarely cross midline)
Other: – Phosphate wasting (hypophosphataemic rickets) – Growth hormone excess (gigantism) – Cushing's syndrome – Thyrotoxicosis – Cardiac arrhythmias – Cholestasis etc - Ovarian cysts secreting oestrogen
Mesomelia =
Shortening of the intermediate segment of limbs
Rhizomelia =
Shortening of proximal segment of limbs
Acromelia =
Shortening of distal segments of limbs
Two subgroups of skeletal dyplasias
Spinal changes dominant or minimal/absent (sitting height)
Multiple epiphysis like dysplasia and metsphyseal dysplasias are characterised by…
Pain and stiffness in joints as well as less pronounced growth failure
Madelung deformity is
Dinner fork deformity of wrist
Keri-Weill dyschondrosteosis is
Mesomelic limb shortening and madelung deformity
Haploinsufficiency of SHOx chromosome like cause of turners short stature
SHOX gene analysis (dated at pseudo-autosomal dominant region at terminal ends of both sex chromosomes)
XXY is taller or shorter or same height
Taller (SHOX dose effect)
Test for GH def
IGF1 and IGFBP3
Differential diagnosis of suprasellar SOL
Craniopharyngioma (calcified) Optic glioma Arachnoid cyst Astrocytoma Epidermis cyst Germinoma Pineocytoma Aneurysm
Complication post op of craniopharyngioma resection (benign)
Recurrence
Obesity (likely from hypothalamic damage)
Male infants testosterone <6m
Same magnitude as early puberty and low indicates hypogonadotrophic hypogonadism
What to replace first in septooptic dysplasia
Cortisol then thyroid to avoid addisonian like crisis
Bamforth-Lazarus syndrome presentation and defect
Homozygous mutation in TTF-2 gene locus
Congenital hypothyroid, poor tone, spiked hair, cleft
Treatment of neonatal graves
Lugol’s iodine, PTU carbimazole, beta block
Pendred’s syndrome clinically
SLC26A4 gene (pendrin mutation which transports iodine across membrane) AR Vestibular abnormalities, small goitre, learning difficulties
TSH on heelprick at lab measurement higher/lower..
Higher
Hypocalcaemia in digeorge from..
Parathyroid aphasia/hypoplasia
Albright’s hereditary osteodystrophy clinically
Osteomalacia cutis, poor linear growth, TSH resistance and pseudohypoparsthyroidism, cataracts, round face, flat nose, short neck, syndactyly, shortened 3-5 metacarpals, short fat
DDx rickets
Calcium def
Hereditary
X linked hypophosphatemic rickets
X-linked dominant disorder with substantial variable expression - loss of function mutation PHEX ( increased renal excretion Po4
Short
Delayed walking
Rickets
Delayed tooth eruption and increased decay
Causes of hyperpsrathyroidism in children
Primary: Sporadic from adenoma MEN 1, 2A McCune Albright Familial (jaw tumour syndrome)
Familial hypocalciuric hypercalcemia
Inactivsting mutation, AD, asymptomatic with low. Ca/cr clearance
First signs puberty in male and female
Male testicular vol > 3ml and female breast buds (oestrogen action)
Central precocious puberty diagnosis and Tx
Diagnosed with gnrh stimulation test and measure if LH and FSH rise to pubertal range (LH dominant cf FSH in thelarche) and then check MRI (other pit function)
Managed with GnRH agonist (leuprolide Lucrin)
CNS irradiation associated with…
GH def
Prepubertal testis indicates..
Peripheral cause of androgen (almost always adrenal (CAH, androgen secreting tumour, hcg secreting tumour, androgen secreting tumour)
Hypogonadotrophic hypogonadism causes
Genetic (KAL1, FGFR1, zgnHT, DAX1, tumours, post head trauma, CHARGE (60-80% defect in CdH7 gene), prader-Willi, kallman, Lawrence-moon-biedl
Chronic disorders
Galactosaemia (75-96%) defect GaLT (galactose-1-phosphate uridyltrsnsferase
Central precocious puberty treatment
Agent of choice Lucrin (depot leuprorelin acetate) an inhibitor of gonadotropin production - intramuscular injection (IM)
Second line Zoladex (goserelin acetate) slow subcutaneous injection
Most common cause for hypothyroidism and investigation of choice
The most common cause of acquired overt hypothyroidism in both children and adults is autoimmune thyroiditis (Hashimoto disease).
An elevated thyroid peroxidase (TPO)
antibody concentration would be most consistent with this diagnosis.
Thyroid gland missed on scintiscan when what is present
Blocking antibodies
Fertility in mcCune Albright syndrome
Normal
Precocious puberty Tx in MAS
Decrease / stop menses – Slow bone age advancement – Improve final height • Tamoxifen 20mg daily • J Pediatr 2003;143:60‐6 • Anastrazole (aromatase inhibitor) and anti‐androgen (spironolactone or flutamide) • JPEM 2002;15 Suppl 3:945‐8 • Ketaconazole • Fulvestrant 4mg/kg IM monthly • Pure estrogen receptor antagonist:
Induce puberty in panhypopit male
Testosterone
MODY types and presentations with genetics
1: Adolescent with gradual hyperglycaemia and beta cell failure - highly responsive to sulphonureas with FHX and no antibodies (HNF1A)
(3: HNF4A has similar presentation but transient neonatal diabetes with large gestational age)
2: GCK present with mild sustained hyperglycaemia non progressive and no secondary complications so no treatment
Can have renal cysts and liver affected
Which stress steroid is used
Hydrocortisone Omit desmopressin (to avoid low serum sodium as hydrocortisone has enough mineralocortical action)
3 x physiological
Turners percent which have puberty spontaneously
30%
Clitoromegaly is a sign of
Exposure to potent androgens
Can be from CAH (remember your case you saw - can have surgery on this to normalise)
Somogyi effect is
Recount hyperglycaemia
Child presents with dental issues and rickets, seizure and low ALP
What is genetic defect and treatment
Hypophosphatasia is caused by a genetic defect of tissue-nonspecific alkaline phosphatase (TNSALP), an enzyme that plays a role in bone mineralization
Treat with pyridoxine
Death DM1 likely due to
DKA
Posterior pituitary hormones
Oxytocin and vasopressin
DM1 sibling risk
5%
Child with DM, DI and optic atrophy
Wolfram syndrome
Schmidt syndrome
Hashimoto
DM
Addisons
Chronic candidiasis associated with what else
Type 1 autoimmune polyendocrine syndrome
Addisons
Hypoparathyroidism
Also thyroid
RarelyDM
(Type 2 all adrenal insufficiency and just endo)
MEN1 genetics and common clinical traits (3 Ps)
MEN1 encodes MENIN (tumour supressor)
AD
Most common: hyperparathyroid
Pituitary
Pancreas
Facial angiomata
MEN 2 genetics and presentation
Gain of function in RET Proto-oncogene
2a: thyroid, phaeo, parathyroid
2b: thyroid, phaeo, AND GI stuff [neuronal dysplasia intestines (like hirsprungs), mucosal and GI neuromas] and thick lips/marfanoid features
Carney complex
Risk endocrine tumours
Myxomas
Skin changes
SRY -> SOX9 -> differentiation of Sertoli cells which secretes?
Serology secrets AMH
Testosterone by leydig cells which needs 5 alpha reductase to make DHT (required for male looking gonads
Turners cause of short stature no ovaries (streak gonads) sexual infantilism?
Haploinsufficiency of the X chromosome
A two-year-old boy presents with an incidentally noted abdominal mass. He is found to have sparse
pubic hair. Investigation confirms he has a hepatoblastoma.
Virilization is most likely in children with ectopic production of:
A. alpha fetoprotein.
B. androstenedione.
C. human chorionic gonadotrophin
D. luteinizing hormone
E. testosterone.
C
Sick euthyroid T3/4 up or down
Down
Central precocious puberty definition
Defined as the onset of breast development before 8 years in girls and the onset
of testicular development (volume >4mL) before the age of 9 years in boys, as a
result of activation of the hypothalamic pituitary gonadal axis
adrenoleukodystrophy mutations in what gene
ABCD1
gene located on Xq28
Hypogonadotrophic hypogonadism 50% has no sense of smell what syndrome
Kallman
Autosomal recessive.
Prenatal and postnatal growth retardation.
Microcephaly, ptosis, anteverted nares, broad alveolar ridges,
syndactyly of the 2nd-3rd toes, severe mental retardation.
70% male.
Genital ambiguity or complete sex reversal.
Low cholesterol and elevated 7-dehydrocholesterol.
Smith-lemli-opitz
Mutations in Δ7-reductase gene on chromosome 11q12-q13.
Neonate with acanthosis nigricans and hyperglycaemia causes (3h
Type A insulin resistance syndrome
Leprechaunism
Rabsom-mendenhall syndrome
DM1 present when what percent of beta cells destroyed
80%
Unawareness of hypoglycaemia is predominantly due to failure of secretion of which one of the following hormones? A. Adrenaline. B. Cortisol. C. Glucagon. D. Growth hormone. E. Somatostatin
A
Adjusted sodium calculation
Na + 0.3(glu-5.5)
What is heavily protein bound
Testosterone
ADH controls?
H2O absorption CD
GH stimulated by
Sleep Exercise Protein Hypoglycaemia (Inhibited by insulin)
Hypoglycaemia awareness due to
Adrenaline
Overweight is BMI >?
85%
Males height growth in puberty is
29cm
Important feature in kleinfelters and mx
Infertility from azospermia
Testosterone and aromatise inhibitors
Can extract sperm and inject it though
MEN2 gene
RET
Endogenous cortisol secretion ?mg/m2/day
6-8
APS1 gene
AIRE
MEN2 gene
RET
What does adrenal cortex, medulla and reticularis make
Cortex is affected in CAH
Medulla makes adrenaline MAD
Reticularis makes androgens RANDY
Hormone responsible for dawn effect
GH
How does metformin work
Suppresses gluconeogenesis and increases insulin sensitivity
Newborn with spikey hair, cleft, congenital hypothyroid?
TTF-2 gene
Bamforth-Lazarus syndrome
