Growth

Question 1

What is the fastest period of growth in a human?

Answer 1

Foetal; 30% of eventual height

Question 2

What factors determine foetal growth?

Answer 2

Maternal size, placental nutrition supply, IGF-2, HPL, insulin

Question 3

What factors determine infantile growth?

Answer 3

Adequate nutrition! Also both parental heights, good health, normal thyroid function. Accounts for 15% of height

Question 4

What factors determine childhood growth?

Answer 4

Pituitary growth hormone which produces IGF-1. Also nutrition, thyroid hormone, vit D. Profound unhappiness reduces GH secretion

Question 5

What factors pubertal growth?

Answer 5

Testosterone and oestradiol increase GH secretion; they also fuse epiphyseal growth plates so early release can lead to early fusion and short stature. Accounts for 15% of final height

Question 6

What is the statistical distance between bands on a growth reference chart?

Answer 6

Two thirds of a standard deviation

Question 7

Which centiles are significant for height?

Answer 7

0.4th and 99.6th if mid-parental height is normal. Also any if markedly discrepant from weight lines. Also serial measurements crossing growth centile lines after 1yr

Question 8

What are the causes of growth hormone deficiency?

Answer 8

Isolated defect or due to pan-hypopituitarism. Abnormal pituitary in congenital mid-facial defects, craniopharyngioma, hypothalamic tumour or head injury/meningitis/cranial irradiation. Look for abnormal visual fields

Question 9

What is Laron syndrome?

Answer 9

Defective growth hormone receptors result in insensitivity. High GF but low IGF-1. Extreme short stature. Treated with recombinant IGF-1

Question 10

What are the causes of Cushing syndrome?

Answer 10

Normally iatrogenic (try alternate day therapies), may be due to pituitary or adrenal pathology

Question 11

What are notable common illnesses which present with short stature?

Answer 11

Coeliac disease, Crohn’s, chronic renal failure

Question 12

Which chromosomal disorders commonly present with short stature?

Answer 12

Down’s, Turner’s, Noonan’s, Russell-Silver’s

Question 13

Which gene on the X chromosome can lead to severe short stature?

Answer 13

SHOX. Thought to account for short stature in Turner’s and tall stature in Klinefelter’s

Question 14

What are the indications for subcutaneous growth hormone?

Answer 14

Severe deficiency, Turner syndrome, Prader-Willi, chronic renal failure, SHOX deficiency and IUGR

Question 15

What causes disproportionate short stature?

Answer 15

Legs>back is skeletal dysplasia; storage disorders cause back>legs

Question 16

What causes tall stature?

Answer 16

Parental height, obesity (though final height is normal due to hastened epiphyseal fusion), hyperthyroidism, excess androgens, excess GH, congenital adrenal hyperplasia, Marfan’s homocystinuria, Klinefelter’s

Question 17

What is Beckwith syndrome?

Answer 17

Overgrowth disorder. Associated with macroglossia, macrosomia, abdominal wall defects, neonatal hypoglycaemia, hemihypertrophy and cancer development. Caused by rampant IGF-1

Question 18

What are the causes of microcephaly?

Answer 18

Familial, autosomal recessive condition (assoc w/developmental delay), congenital infection, after an insult to the developing brain (assoc w/cerebral palsy and seizures)

Question 19

What are the causes of macrocephaly?

Answer 19

Tall stature/familial, raised ICP, hyrdocephalus, subdural haematoma, tumour, neurofibromatosis, Sotos, CNS storage disorders