Endocrinology Flashcards
21 hydroxylase deficiency
Increased 17oh progesterone, virilized female, aldosterone deficiency salt wasting. Treat with glucocorticoids and mineralocorticoud a
11 hydroxylase deficiency
Elevated deoxycorrisol and deoxycorricosterone. Virilization of female. Elevate doc causes sodium retention. Treat with glucocorticoid
What should you order to work up short stature?
IGF1, Bone Age, karyotype in females, CMP, ESR, CBC, TSH
Cushings disease
ACTH secreting anterior pituitary tumor
What is the relationship between seratonin and cortisol
Seratonin stimulates the release of CRH
Relationship of dopamine and prolactin
Prolactin is under tonic hypothalamic inhibition by dopamine sent down the pituitary stalk. Anti-DA drugs cause increased prolactin
Relationship of TRH and prolactin
Both increased by anti DA drugs. Prolactin is also increased in hypothyroidism
Hall-Pallister Syndrome
Absence of the pituitary gland and associated with hypothalamic hamartoblastoma, polydactyly, nail dysplasia, bifid epiglottis, imporferate anus, heart, lung, kidney abnormalities.
Rieger Syndrome
Deficiency of anterior pit hormones, coloboma, glaucoma, kidney, GI, umbilical anomalies.
Septic optic dysplasia
abnormailtiy of the optic nerve, agenesis or hypoplasia of the septum pellucidum or corpus collusom, often hypothalamic insufficiency. 2/2 abnormality in transcription factor HESX1
What is a solitary maxillary central incisor a sign of?
High likelihood of GH deficiency
Laron syndrome
Normal amount of GH, but defective GH receptors. Low levels of IGF -1. Treat with IGF -1
Constitutional growth delay
A variant of normal growth. Normal growth during the first 4-12 months of life, but then growth rate slows to the height and weight are less than the 3rd percentile. By 2-3 years of age, growth resumes at >5cm/year. GH studies normal, bone age is delayed and mirrors height age instead of chronologic age. Kids usually reach normal adult height, may have delayed puberty.
How is genetic short stature different from constitutional growth delay?
Has normal bone age for chronologic age, as opposed to delayed bone age seen in constitional growth delay.
What three factors differentiate genetic short stature, constitutional growth delay and GH deficiency?
family history, growth velocity, bone age.
Signs of hormone deficiency
decrease in growth velocity, delayed bone age, maybe fam history
What are side offects of GH treatment?
SCFE, psuedotumor cerebri, transient carbohydrate intolerance, transient hypothyroidism, scoliosis
Mid -parental hieght calculation
for boys = {mom hieght + dad height + 13 cm} / 2
For girls = {mom height + dad height - 13cm} /2
What studies should you order if you suspect DI?
serum osm, UA and urine osm. ADH level. Can do a water deprivation test, or DDAVP test
Treatment of central DI
DDAVP, intranasally or orally
Treatment of nephrogenic DI
Low sodium diet to reduce obligatory water loss from kidney. Thiazides reduce urine output, indomethacin.
Abnormal causes of tall stature
Marfan, homecysteinuria, Klinefelter
Marfan genetics and eye findings
AD, upward subluxation of lens
Homocystinuria
Intellectual disability, marfanoid habitus, downward subluxation of lens
Sotos syndrome
Born above the 90th percentile and then grow rapidly in the 1st year of life to >97th percentile until age 4-5 then returns to normal. Puberty normal or a little early. Patients have big hands and feet, clumsy and un coordinated. May have intellecutal disability. GH levels are normal. Long narrow face, pointed chin.
Most common anterior pit tumor in adolescents
prolactinoma
Treatment for prolactinoma
bromocriptine (DA agonist). or surgery
Beckwith Wiedemann syndrome
Excess IGF -2 2/2 lack of demthylation at 11p15. Fetal overgrowth syndrome (including pancreas). Macroglossia, HSM, excess insulin. Increased risk of hepatoblastoma, WT
Screening needed in patients with Beckwith Weidemann
Abdominal US q3mo until 8 yrs, afp q6 weeks until age 6
What is the first sign of puberty?
breast development and increased testes size
What hormone controls closure of epiphyseal plates?
Estrogen
Average length of time from initial sign of pubery to menarche?
2-2.5 years
When does peak height velocity occurs?
breast stage 2-3, always precedes menarche
How much more growth do females have after menarche?
about 3 more inches
At what Tanner stage does menarche occur
Tanner stage 4
normal male puberty
ages 9-14
normal female puberty
ages 8-13
Precocious puberty ages
< 9 males
Most common brain lesion that causes true precocious puberty
hypothalamic hamartoma - contains ectopic neural tissue that contains GNRH secretory neurons and functions as a GNRH pulse generator
Treatment of gonadotropin dependent precocious puberty
leurpolide - a GnRH analog that interrupts the pulsatile nature
Mccune Albright Syndrome
mutation in cAMP formation therefore any receptors that have cAMP dependent mech are affected. Therefore TSH, FSH, LH, ACTH affected. Get oversecretion of hormones. Cafe au lait spots and fibrous dysplasia of skeletal system.
Definition of premature thelarche
isolated breast development in first 2 years of life. growth, bone maturation and genitals are normal
Definition of premature adrenarche
isolated pubic hair or other androgen effects before 8 in girls before 9 in boys.
what percent of boys with enlarged testes have a brain tumor?
25-75%. Premature isolated testelarche does not exist! This is precocious puberty
Pubertal gynecomastia occurs during which tanner stages?
2-4
When do boys with gynecomastia need further workup?
When occurs in atypical tanner stage (1 or 5). atypical age 16, abnormal pubertal progression, patients with macrogyneco, patients requesting surgery
What ingestions can cause premature thelarche and psuedopuberty?
estrogen creams, OCPS, excessive soy, tea tree oil, lavender
What causes increased TBG thus increased total T4?
estrogens, pregnancy, tamoxifen, narcotics, biliary cirrhosis, hepatitis
What causes decreased TBG thus low total T4
androgens, glucocorticoids, nephrotic syndrome
What drugs blcok peripheral conversion of T4 to T3?
propranolol, glucocorticoids, PTU, amiodarone
Does a thyroglossal duct cyst move with swallowing?
Yes
Most common cause of congenital hypothyroidism
thyroid dysgenesis
Relationship of hypothyroidism and jaundice
low Thyroxine causes slowed conjugation of bilirubin
signs and symptoms of congenital hypothyroidism
enlarged posterior fontanelle, delayed dentition, large tongue, myxedema, devo delay
What percent of patients with DM1 have thyroid disease?
10-15%
What antibodies are found in hashimotos?
Antithyroglobulin, Antithyroperoxidase
Drug treatment of choice for hyperthyroidism in peds
MTX over PTU (risk of hepatotox and death)
What percent of thyroid nodules in peds are malignant?
25% Much less in adults
MEN 2a
Medullary thyroid cancer, pheochromocytoma, hyperparathyroid
MEN 2b
Medullary thyroid cancer, pheochromocytoma, and marfanoid habitus and digestive neurofibromas
Most common cause of pediatric thyroid cancer?
Follicular carcinoma
What is the first step of workup in find a thyroid nodule?
Check TSH, if suppressed do thyroid uptake scane to look for HOT nodule, if elevated or normal do an ultrasound to confirm the presence
What is the best tumor marker to follow for thyroid cancer?
Thyroglobulin
Actions of PTH
causes release of bone calcium stores, decreases renal excretion of calcium, but increases Phos excretion, increases activity of hydroxlase that converts vitamin D
Actions of 1,25-OH D3
Increases Ca and PO4 absorption from gut, Increases Ca resorption from bone and increases Ca and Phos reabsorption from kidneys
High ca and high pos are due to
high vitamin d levels
High ca and low phos are due to
high PTH levels
Low Ca and Low phos are due to
Low vitamin D levels
Low Ca and high phos are due to
low PTH levels
What does calcitonin do?
Slows down osteoclasts which causes decreased bone resorption and increases renal calcium clearance. DECREASES calcium
Effect of glucocorticoids on bone
help maintain osteoblasts function, but large amounts decrease the bonematrix and cause calciuria
Effect of estrogen on bone
decreases bone resorption and increases osteoblastic activity
APS1
Autoimmune hypoparathyroidism, Addison disease and chronic mucocut candidiasis. AR. MAy also have hair loss, vitiligo, hepatitis
APS 2
type 1 DM, thyroid disease, Addisons
What endo disorder is associated with basal ganglia calcification
hypoparathyroidism
Psuedohypoparathyroidism
resistance to PTH; multiple forms exist.
What are radiologic signs of rickets?
irregular calcification, cupping of metaphysis, fraying and widening of growth plate, diffuse osteomalacia
What is hypophosphatemic rickets
Renal disorder, X linked. causes over active FGF 23 which causes phosphate wasting. Extremely low serum phos, high urine phos, elevated alk phos and normal PTH, normal vita D
MEN 1
pituitary, parathyroid and pancreatic hyperplasia or neoplasia
3 zones of adrenal cortex
Glomerulosa (mineralocorticoids), fasciculata (cortisol), reticularis (androgens)
What is the best test to diagnose someone with Cushing’s disease
24 hour urine cortisol
Adrenoleukodystrophy genetic pattern
X linked
Adrenoleukodystrophy underlying issue
high levels of very long chain fatty acids - peroxisome defect
Clinical presentation of Adrenoleukodystrophy
Degenerative neurologic disorder that begins in childhood or adolescense, progresses to severe dementia, loss of vision, hearing, speech, gait
What is the most common form of CAH?
21 hydroxylase deficiency. Elevated 17- hydroxyprogesterone
Characteristics of 21 hydroxylase CAH
Most infants are virilized and salt losers (25% do not waste salt). will have fast post-natal growth and precocious puberty.
Elevated metabolite in 11B hydroxylase deficiency
11-deoxycortisol
Clinical signs of 11B hydroxylase deficiency
No salt wasting, instead have hypertension because one of the metabolites Deoxycorticosterone has mineralocorticoid activity . Virilized.
Clinical signs of 3B hydroxysteroid
Lack cortisol, aldosterone and testosterone, but have increase DHEA. Salt wasting but mild virilization, boys with hypospadias, shortly after birth get axillary and pubic hair.
Treatment of CAH
hydrocortisone to treat adrenal insufficency and prevent excessive production of androgens. If have salt wasting give florinef and salt.
Most common cause of Cushing’s syndrome in infants
Adrenocortical tumor
How does cushing syndrome affect growth?
Obesity with poor height velocity.
When are cortisol levels the highest?
8am, decrease by 50% by 8pm
When do you check cortisol when screening for adrenal insuff vs Cushings?
For insuff want to check AM cortisol, but for cushings, no diurnal pattern thus can check mid day.
What do you test to diagnose a pheo?
Urinary VMA and metanephrines
When removing pheochromocytoma, what must be given
alpha and beta blockers, lots of fluids.
What are genetics of noonan syndrome?
AD. Variable expression. Mapped to chromosome 12q
Heart defect of noonan syndrome
Pulmonic stenosis
Clinical manifestations of noonan syndrome
Short stature, neck webbing, pectins excavatum, hypertelorism, downward slanting palpebral fissures, intellectual disability in 25%, hearing loss
Karyotype of Klinefelter syndrome
47XXY
Clinical signs of Klinefelter syndrome
Intellectual disability, psych issues , small testes, gynecomastia, long legs, increased brca risk
Genetics of kallman syndrome
X linked
Clinical features of kallman syndrome
Anosmia and hypogonadotrophic hypogonadism
What tanner stage should boys be at if they have gynecomastia ?
Tanner 2-4. If tanner 1 or 5 need for eval
Incidence of Turner syndrome
1/2000 live births. Risk does not increase with maternal age. 3% of conceptions are x0 but 99% of these spontaneously abort
What r turners kidney findings?
Pelvic kidney, horseshoe kidney, double collecting sys, one kidney
Diagnostic criteria of PCOS
2 of following : 1. Irregular anovulatory cycles 2. Signs of hyperandrogenism chemical or physical 3. Poly cystic ovaries
Side Effect of danazol on fetus
Ambiguous genitalia
What is Denys drash syndrome?
Occurs in 46xy associated with nephropathy, ambiguous genitalia (formed mullerian ducts), WT
5 a reductase deficiency
Decreased production of DHT which is necessary for development of male external genitalia. Infants present wih small penis, bifid scrotum, blind vaginal pouch Usually characterized as female at birth and penis enlarges at puberty
Androgen insensitivity syndrome
46xy, x linked , have testes and high/normal testosterone, but have defect in androgen receptor. Can be completely female appearing but with blind vaginal pouch
Somogyi Effect
hypoglycemic episodes that may manifest as late nocturnal or early morning sweating, night terror and headaches 2/2 hypoglycemia followed by hyperglycemia
After how many years of Type 1 DM do you start screening retinopathy and nephropathy?
5 years
What is MODY?
AD type of diabetes, onset 9-25 years. Respond to sulfonureas
At what age do you need to work up primary amenorrhea?
Age 15. If havent had period by age 15 need to work it up.
At what osmolality does thirst kick in?
295mOsm/L
What abnormalities is an ectopic posterior pituitary associated with?
Usually seen as an ectopic bright spot at the base of the third ventricle. Anterior pit problems because infundibulum often does not migrate appropriately. Can have isolated GH def or panhypopit
What is cerebral salt wasting and how does it differ from SIADH?
due to hypersecretion of atrial natriuretic peptide. Seen in patients with CNS disorders. Hyponatremic, hypovolemic, very high urine sodium >150, high urine output, low ADH (In contrast SIADH is euvolemic, slightly high urine sodium >40, low urine output, high ADH)
Treatment of cerebral salt wasting
IV fluid replacement and salt replacement
Men 2a
hyperPTH, medullary thyroid CA, pheo
Men 2b
medullary thyroid CA, pheo, marfanoid, mucosal neuromas
What is the Carney complex?
an AD disease with blue nevi, cardiac and skin myxomas, sexual precocity, primary pigmented adrenocortical disease. Associated with thyroid and pituitary tumors
Liddle syndrome
AD disorder with hypertension and hypokalemia. Renin and aldo are low
Laurence-Moon-Biedl/Bardet-Beiedl syndrome
Retinitis pigmentosa, obesity, intellectual disability, polydactlyl, genital hypoplasia, hypogonadism
Effect of ketoconazole
directly inhibits testosterone synthesis. Can cause gynecomastia
In a girl >16yo with primary amenorrhea, which is the most helpful study?
karyotype
Perrault syndrome
XX gonadal dysgenesis with SNHL
What infectious disease causes increased risk of type 1 DM in kids?
congenital rubella
Somogyi vs dawn effect
Both have early morning hyperglycemia, but Somogyi effect is characterized by late nocturnal/early morning hypoglycemia, followed by hyperglycemia, glucosuria, ketosuria, ketosis - thought 2/2 too much insulin thus need to reduce the dose. Important to distinguish from Dawn effect - elevated glucose bc insulin is wearing off. Increase insulin.
When do you start screening in DM 1?
5 years after diagnosis - microalbumin, optho (>age 10), lipids (>age10), celiac, thyroid
how is prenatal screening for CAH performed?
molecular genetic testing of fetal cells, not amniotic levels of 17 OH progesterone
Which genetic condition is associated with hypercalcemia
Williams syndrome
what can cause delayed eruption of teeth?
vitamin d deficiency
Tell me about vitamin D resistant rickets
Type 1 - cannot produce 1,25 - OH vita D. Type 2 - resistant to 1,25 OH vita D. Both are AR
How is hypophosphatemic rickets inherited?
X linked DOMINANT
Which CAH has virilization of both XX and XY?
3B HSD - DHEA builds up which is too weak to fully virilize males, but strong enough to virilize females
The risk of a solitary thyroid nodule in a child is malignant is approximately:
33%
What do you treat persistent hyperinsulinemic hypoglycemia of infancy with?
diazoxide, octreotide a distant second
