Growth Flashcards
List 3 growth factors important in fetal life
- Insulin
- Epidermal growth factor
- Fibroblast growth factor
List 4 endocrine factors important for postnatal growth
- Growth hormone and IGF1
- Thyroid hormone
- Sex steroids (pubertal growth spurt)
- Glucocorticoids
How does the upper:lower segment ratio change over time?
Obesity ______ growth hormone and _______ IGF1
Obesity decreases GH and increases IGF1
Mechanism: increased GH receptors
Growth charts are available for the following conditions:
- Achondroplasia
- Down syndrome
- Noonan syndrome
- Williams syndrome
- Turner syndrome
- Russell-Silver syndrome
The majority of SGA infants show good catch-up growth. About ______% have lifelong short stature
20%
List 3 endocrine sequelae of SGA after birth
- Premature adrenarche
- Precocious puberty/menarche
- Dyslipidemia
- Insulin resistance
- Obesity
- PCOS
List 5 clinical features of congenital growth hormone deficiency
- Short stature
- Cherubic/pudgy appearance
- Immature high-pitched voice
- Delay in skeletal maturation
- Hyperlipidemia (elevated total chol and LDL)
- Microphallus
- Hypoglycemia and seizures
- Breech presentation
- Normal intelligence
- Midline defects (ex. SOD)
______% of children do not have an adequate rise in GH when tested with one agent
10%
Therefore two methods are necessary to diagnose GHD
List 4 agents that may be used to test for GHD
- Arginine (0.5 g/kg IV)
- Clonidine (0.1 mg/m2 PO)
- Glucagon (applies to GH and ACHT, 30 mcg/kg)
- Oral levodopa
- Insulin (no longer used, applies to GH, ACTH and cortisol)
- GHRH
- Synthetic GHRP’s (GH releasing peptides)
What factors must one consider when interpreting IGF1? List 3
- Starvation lowers IGF1
- Patients with constitutional delay have low IGF1 for chronologic age but normal for skeletal age and will not benefit from GH therapy
- Patients with normal IGF1 may still benefit from GH therapy
List 5 complications og GH therapy
- Slipped capital femoral epiphyses (most common in hypothyroid)
- Pseudotumor cerebri
- Tendency toward diabetes in predisposed patients
- Gynecomastia
- Theoretical risk of promoting growth of pre-existing cancerous cells (usually wait 1 year after cancer treatment to start GH)
- Elevated LDL, low HDL
- Development of GH antibodies/cessation of growth
What conditions are approved by FDA for treatment with growth hormone?
- Turner syndrome
- Growth hormone deficiency
- Small for gestational age without catch-up growth
- Renal disease in childhood
- Noonan syndrome
- ?Prader Willi syndrome
- Idiopathic short stature (height below 2.25 SD for age, predicted to fall short of reaching normal adult height)
List 1 condition which can be treated with recombinant IGF-1
- Laron dwarfism (GH resistance)
List a differential diagnosis for genetic syndromes of tall stature
- Sotos syndrome (Cerebral gigantism, NSD1 gene)
- Marfan syndrome (FBN1 gene)
- Homocytinuria (CBS gene)
- Beckwith Wiedemann Syndrome (loss of maternal 11p15.5)
- XYY Syndrome
- Klinefelter
