Normal and Abnormal Growth

Question 1

What is the middle line in a bell curve?

Answer 1

MEDIAN/ Mean/ 50th Centile

In an uneven chart the median may not = the mean

Question 2

What is standard deviation?

Answer 2

A measure of variability

Question 3

What is the Z score?

Answer 3

Number of SD from the mean

Question 4

Centiles on a growth chart are _____ of a SD apart?

Answer 4

2/3

Question 5

Describe growth velocity in childhood? What is this determined by?

Answer 5

Grow really fast for the 1st year then growth drops then get increase in growth velocity at pubertal growth spurt before decreasing again. Initial growth is determined by GH. Pubertal growth by age of puberty.

Infancy > nutrition and insulin
Childhood > GH thyroxine
Puberty > GH and sex steroids

Question 6

A child shows normal growth if….

Answer 6

their measurements are within normal range compared with children of their age and their rate of growth is within the normal range compared with children of their age

Question 7

A child who is growing normally is…

Answer 7

unlikely to have any major underlying problems

Question 8

When is a child described as being on a centile? When are they between?

Answer 8

If a point is exactly on the centile line or within 1/4 of a space on a centile line the child is described as being on ‘X’ centile. If not they should be described as between centile X and Y. A centile space is the distance between 2 centile lines.

Question 9

Falling off height centiles may suggest what?

Answer 9

An endocrine issue

Question 10

What does the adult height predictor do?

Answer 10

Allows you to predict adult height based on current height but with regression adjustment. 4/5 will have adult height +- 6 cm.

Question 11

What is the mid parental centile?

Answer 11

Average adult height centile to be expected for all children off these parents. Also incorporates regression. Comparing this to the child’s current height centile can help assess whether the child’s growth is proceeding as expected.

Question 12

Define precocious puberty? Is it more common in girls or guys?

Answer 12

Less than 8 in girls and 9 in boys

More common in girls

Question 13

What is first sign of puberty in boys and girls?

Answer 13

Boys= testicular volume more than 4 ml
Girls= breast budding (thelarche)

Question 14

When does menarche in girls usually occur?

Answer 14

2-3 yrs after onset of puberty

Question 15

Define delayed puberty? Is it more common in girls or guys?

Answer 15

No breast development by age 13 in girls or no increase in testicular volume by age 14 in boys. It is more common in boys.

Question 16

Describe peak height velocity in puberty in boys and girls? Why does this mean men are generally taller than women?

Answer 16

Peak height velocity in girls occurs B2-3 (av 12 yo) in girls but in boys G4-5 (av 14 yo). This is why men tend to be taller than women as they get to grow for longer before their final growth spurt.

Question 17

Tests you may do for a growth problem?

Answer 17

Bloods for gonadotrophin, growth factors, testosterone, estradiol, thyroid function, karyotype, any other suspected pathology
Bone scan- children with constitutional growth delay tend to have a younger “bone age” and enter puberty later, they grow until later age however so catch up. Familial short stature kids will in contrast not have delayed puberty just be shorter.
Dynamic Function tests
MRI brain, USS uterus.

Question 18

Describe 6 classifications of short stature?

Answer 18

• Genetic short stature- normal just shorter like parents
• Constitutional growth delay- delayed growth but do eventually catch up
• Dysmorphic syndrome- downs, achondroplasia
• Endocrine diseases- GH, thyroid
• Chronic diseases
• Psychosocial deprivation

Question 19

Describe congenital hypothyroidism

Answer 19

AKA cretinism- this causes growth retardation with short limbs, coarse dry skin, lack of hair and teeth, mental deficiency. Can be endemic (due to iodine deficiency) or sporadic (due to congenital hypoplasia or absence of the thyroid) deaf mutism is often present.

Question 20

Describe growth hormone deficiency

Answer 20

Congenital is due to abnormal genes in production or action of GH or in structure of the brain. Like an adult it can also be acquired due to a brain tumour.