• Illustrative pattern of normal growth
• Illustrative pattern of abnormal growth
• The differential growth and maturation of the various organs and tissues in our bodies
• The basic conceptual framework of multipotent turned differentiated cells
• The principles governing the balance between control of cell division, survival and death
• Regenerative / reparative power

• Varies with age

1. Birth: more water (% BW) than in adults
2. Important in drug pharmcokinetics
3. Important in premies

• Different nutritional requirement dependant on age
• Cell size and number
• Lean body mass
• Adipose tissue

SLIDE: Different growth patterns of selected organs

1. Ear length and width
2. Eye (palpebral fissure length), interpillary, inner/ outer canthal distance)
3. Nasal height, philtrum
4. Chest circumference, internipple distance

SLIDE: Ears above eye levels; Hands and fingernail measurements

• Physical measurements for growth - different ways to report on the audited states of out body
• Ht is a mathematical sum of the head, spine and LL

1. Achondroplasia: primarily affect limbs
2. Thalassaemia; iron toxicity; need chelation, which can damage spine and growth plate -> brachyspondyly (shortened trunk/ spine)
3. Therefore, may know someone is short, but need details - which part of their body is shorter?

• Various charts for standard body measurements

1. Standard deviation score (SDS)
2. Wt and ht "age"
3. Body mass index (BMI) - wt (kg) / ht (m) squared
4. Ponderal index - weight (g) / ht (cm) cubed: nutritional status in newborns
5. Mid-parental ht (MPH)

• Integrate genetic component of ht
• Male = (sum of parental heights + 13cm) / 2 +/- 7.5 cm
• Female = (sum of parental heights - 13cm) / 2 +/- 7.5 cm

1. Bone age - skeletal maturation index

• Triphasic human growth

1. Growth vel highest in 1st 2 yr: not GH dependent; even with congenital GH deficiency, ht may be normal in this period
2. Fall in childhood period
3. Upsurge in adolescence: sex steroid, insulin important

• Infant-childhood-puberty (ICP) model

SLIDE: Length and weight - female (0-3y); Stature and weight - female (2-18y)

• Ethic difference exists, but getting smaller
• Turner syndrome: mean adult ht similar across all ethnic groups
• Therefore, certain control resides on certain genes

SLIDE: Oscillation of growth velocity - a normal phenomenon

SLIDE: Variation in growth velocity throughout growth

SLIDE: Variation in growth velocity throughout growth

SLIDE: Differential temp of sexual maturation

• Birth weight is regained by the 10-14th day
• Average weight gain/ day:

1. 0-6m = 20g
2. 6-12m = 15g

• BW doubles at 4m, triples at 12m, quadruples at 24m
• During a second year, average wt gain/ mth = 0.25 kg
• After age 2 years, average annual growth until adolescence = 2.3 kg

• Supine length is on average 1 cm more than that of standing ht in first 2 years
• By end of first year, birth length increases by 50%
• Birth length doubles by 4 years, triples by 13 yr
• Average ht gain during second year = 12 cm
• After age 2 yr, average annual growth until adolescence >= 5 cm

• Average head growth/ week

1. 0-2m = 0.5cm
2. 2-6m = 0.25cm

• Average total head growth from

1. 0-3m = 5cm
2. 3-6m = 4cm
3. 6-9m = 2cm
4. 9-12m = 1cm

• Skeletal maturation
• Bone age
• Dental age

SLIDE: X-ray bone age

SLIDE: Proportion of adult height attained at any given bone age

• Eg. Girl with bone age of 13 yr, only 5% more to go
• Eg. Boy with bone age of 13 yr, about 10% more to achieve
• Can project potential outcome of Pt's - decide whether to treat (eg. GH)
• Delay puberty: LHRH analogue - allow bone growth for longer time

SLIDE: Development of dentition - primary (deciduous teeth)

 SLIDE: Development of dentition - secondary (permanent teeth)

1. Genetic factors
2. Sex: males are taller
3. Early life event - programming: during foetal life (eg. Intrauterine growth retardation - can remain short for ever 20-25% small for gestation age) - related to metabolic like DM, HT

• Early or late puberty: precocious or delayed puberty
• Genetic mutations causing pathological obesity
• Genetic mutations causing skeletal dysplasias
• Genetic mutation affecting the regulation systems (endocrine and paracrine)

• Genes regulating structural development of the hypothalamo-pituitary-end organ axis
• Differentiation of primitive cells into specialised hormone secreting cells

1. GHRH, somatotrophin, LHRH, TRH (hypothalamus)
2. GH, LH, FSH, TSH (pituitary)

• Bold: most important for linear growth
• Pit-1 (GH, prolactin & TSH), PROP-1 (GH, prolactin, TSH & ACTH) and Kalig (LHRH)

SLIDE: The regulators of pituitary development

 OVERVIEW OF PITUITARY TRANSCRIPTION FACTOR DEFECTS

• Genes involved in the physiological regulation of the secretions of these hormones
• Genes directly encoding these hormone
• Genes involved in the response to these hormones/ growth signals

• Genes regulating the structural development of the skeleton

1. Chondrocytes
2. Osteoblasts
3. Osteoclasts
4. Collagen
5. Bone matrix

• Genes affecting the regulation of calcium and phosphate metabolism: eg. Sex-linked hyperphosphaturic rickets
• Genes regulating the balance in the osteoblast and osteoclast functions: imbalance in re-modelling

• Nutrition - ethnic differences
• Seasonal variation in growth: doesn't usually affect growth
• Disease
• Psychological disturbance: deprivation, stress
• Socio-economic factors
• Secular trend: generations getting taller

• Low BW
• Dysmorphic syndromes
• Negative energy balance

• Inadequate supply of energy

1. Poor intake (anorexia) - primary (neuro deficit - cannot chew or swallow) or secondary
2. Malnutrition - global or micronutrients
3. Malabsoprtion - general or selective (coeliac disease)

• Increased consumption / loss of energy

1. Chronic respiratory distress/ heart failure
2. Thyrotoxicosis
3. DM
4. Usually reversible and transient

• Mostly exogenous (positive energy balance assoc. with over-eating) and associated with normal/ tall stature (increased nutrition promotes insulin secretion)
• Pathological - more usually associated with short stature and other abnormal clinical features (reasons other than over-eating; genetic + endocrine) - eg. Prader-Willis syndrome)

• Constitutional delay of growth and puberty
• Malnutritions
• Achrondroplasia
• Turner
• GHD

SLIDE: transient deceleration due to asthma with topical steroids -> growth follows a line (if deviate from track with deceleration, will tend to go back on track with acceleration)

Growth is somehow programmed and transient deviation from the set trajectory may be followed by readjustment back to the preset pattern

This is more prominent for growth in the early years. Similar for weight

SLIDE: Catch up growth

8yo girl: chronic asthma treated with inhalation steroid

 SLIDE: Skeletal dysplasias - comparative curves - disease-specific growth charts

SLIDE: Achondroplasia (male) - height and head circumference

SLIDE: Noonan syndrome - stature (males) - don't deviate from norm as much as achondroplasia

SLIDE: Noonan syndrome - stature (females)

SLIDE: GH deficiency - treated with GH. YWH. Hereditary isolated GH deficiency. 1st 2 years not so GH-dependant, therefore growth suffered more in 3-4th year

• Dysmorphic syndromes - Soto, Weaver, Marfan
• Familial tall stature
• Obesity in early life (< 2yo)
• XS GH
• XS sex steroids

• Familial
• Transient: eg. Excess sex steroid (early growth then premature closure) - eg. Congenital Adrenal Hyperplasia, gonadotropin independent precocious puberty, brain tumour

 SLIDE: Marfan - stature and wt

SLIDE: Marfan - upper:lower segment ratios. Lower ratio: limbs are relatively long, trunk relatively short. Can be due to hypogonadism in Kleinfelters because spinal growth in puberty is very prominent

SLIDE: XS growth. 7yo Mongolian girl. Hypothalamic haematoma and true precocious puberty. At age 6, height was like average 9 yo, bone age at 12 yo - eventually she would be short (bone age already so advanced)

The series of changes through which cells, tissues or organs achieve their mature functional states

Definition: American Association of Mental Retardation

• Significantly sub-average intellectual functioning existing concurrently with deficit in adaptive behaviour and manifest during the development period
• Adaptive behaviours = the effectiveness with which the individual meets the standard of personal independence and social responsibility expected of his age and cultural group

• Age of onset < 18yo
• Significantly sub-average abilities in intellectual function
• Limitation in two or more of the following adaptive skill areas

1. Communication
2. Self care
3. Home living
4. Social skills
5. Community use
6. Self direction
7. Health and safety
8. Functional academics
9. Leisure and work

• Speech problems
• Delayed development
• Suspected hearing loss: picked up by MCH (Maternal & Child Health Clinic), parents
• Children and risk for developmental problems: small for gestation, premie (come to paediatrician for regular f'up)
• Behaviour problems
• School failures
• Physical impairment
• MR
• Visual impairment

• Developmental problems
• Motor impairment
• Visual impairment
• Hearing impairment
• Mental retardation
• Psychological difficulties
• Social problems

• Gross motor: Upright posture
• Fine motor: Flexible fingers (hand-eye co-ordination)
• Language abilities
• Complex social systems

• Motor
• Adaptive: visual-motor / visual-spatial
• Language
• Personal-social

• Define the disability - present or absent
• Define the progress: static or progressively deteriorating
• Identify underlying reasons for the problem - reversible / irreversible
• Learn the right clinical tools for performing the assessment
• Learn about the limits of these tools
• Refer when appropriate

• Parental concerns about delayed development
• Suspected MR
• Lack of language in the absence of deafness
• Patient acts as if deaf or blind
• Behavioural disturbance: eg. At school
• Excessive irritability or lethargy in infancy
• Feeding dysfunction or poor sucking

• Microcephaly
• Dysmorphic physical features
• Delay in disappearance of primitive reflexes
• Hyperactive or hypoactive foetus
• Abnormal foetal presentation
• Excessive irritability or lethargy in infancy

• Good Hx - take advantage of asking for discriminatory features - need background info (known developmental milestones)
• Good discriminatory features - measurable; limited variations - always document
• Focus on functionally important dimensions - integration into life

• Chin up 1m
• Head up 4m
• Roll (prone to supine) 5m
• Sit along 8m
• Pull to stand 9m
• Cruise 10m
• Walk along 13m
• Stairs 20m
• Stairs (alt feet) 30m
• Tricycle 36m
• 2 wheeler 36m

• Unfisting 3m
• Reach and grasp 5m
• Transfer 6m
• Handedness 24m

• Fingers 10m
• Spoon 15m
• Fork 21m
• Independent feed 36m

• Cooperate 12m
• Pull off socks 15m
• Unbutton 30m
• Button 48m
• Shoe tying 60m

• Social smile 6-8w
• Recognise mother 3m
• Laugh 4m
• Gesture games 9m
• Understand 'no' 9m
• One-step command 12m
• Two-step command 24m

• Coo 3m
• Babble 6m
• Da-da (inapp) 8m
• Da-da (app) 10m
• 1^st word 11m
• 2^nd word 12m
• 2-6 words 15m
• 2-word phrases 21m
• 2-word sentences 24m
• 3-word sentences 36m
• Echolalia 9-30m (stereotyped repetition of another person's words or phrases)
• 4 colours 48m

• Loss of primitive reflexes - prerequisite for purposeful controlled movements to develop
• The development of a body schema or image through interpretation of proprioceptive, vestibular, tactile and visual information
• The development of postural control which depends on the reflex adjustment of tone in a large number of muscles in response to visual and proprioceptive feedback
• An increasing ability to interpret the visual information in the environment in order to judge, for example, distance, depth trajectory, and wt correctly
• Postural control develops in a cephalocaudal direction - head control, sitting, standing, walking, running
• In parallel with the advancing postural control the child is able to acquire increasingly accurate manipulative skills

• Scribbles 1y
• Copies vertical line 2y
• Copies circle 2.5y
• Copies + draws circle 3.5y
• Draws square 4.5w
• Draws triangle 5-6y

• Determinants
• Neuromuscular - co-ordinate respiration with precise and rapidly executed movements of the articulators (lips, tongue, teeth, pharyngeal walls and vocal cords)
• Structural - cleft lip and palate; severe malocclusion, tongue posture and tongue thrusting habits
• Disorders
• Articulation defects
• Stuttering or developmental dysfluency - genetic and anxiety-provoking
• Voice disorders - anatomic abnormalities or URI

• Determinants
• Auditory - intact hearing is vital
• Intellectual
• Environment - environmental stresses must be extreme to interfere with language development
• Disorders
• Vocabulary defects
• Grammatic and syntactic deficits
• Pragmatic deficits

• 3m - no response or inconsistent response to sound or voice
• 9m - no response to his or her name
• 12m - stopped babbling or did not babble yet
• 15m - does not understand the words no and bye-bye
• 18m - no words other than mama and dada
• 2y - no 2-word phrases
• After 2y - still jargons or echoes excessively
• 2.5y - no simple sentences
• 3y - speech in intelligible to family
• 3.5y - speech not intelligible to strangers

• Social reaction to others
• Skills such as feeding, elimination, dressing

SLIDE: Denver developmental screening testing in achrondroplasia

 RECEPTIVE LANGUAGE SKILLS - 50^th PERCENTILE

• 12m - understands where is mother
• 18m - points to one body part
• 18m - follows two-step commands 2 times out of 3
• 2y - knows 6 parts
• 2-2.5y - understands concept of one
• 2.5 - points to spoon, ball, cup by use
• 3y - recognises day and night
• 2.5 - knows 3 out of 4 prepositions
• 4 - recognises colours
• 4-4.5 - understands concept of three
• 4.5-5 - identifies right and left on self

12m - knows 2-3 single words

18m - uses 2-word sentences

2y - refers to self by name

2.2.5 - uses plurals, I

2-2.5 - converses in sentences

2.5-3 - gives full names

3-3.5 - comprehends old, tired, hungry

3-3.5 - can draw opposite analogies 2/3 of the time

4 - comprehends senses

4.5-5 - defines words correctly 6/9 of the time