Growth Abnormalities Flashcards
Most notable time for physical growth & ↑ in complexity of function
0-5 Years Old
Brain grows to 2/3 of the adult brain size
by age _____
2½–3 years
Identifying disturbances in development
during these early years is critical because time sensitive interventions may be instituted to address developmental issues
Ages 2-5
Concerns with 2000 growth charts
2000 growth charts use NHANES data (1960’s-1990s) which compares current childs weight status to a time before the current obesity epidemic
CDC growth charts
- 16 charts (8 for boys, 8 for girls): Ability to plot head circumference, height, weight, BMI and (in some cases) compare these to one another
A child’s growth & height potential is determined largely by _____
genetic factors
Most children achieve an adult height within ____ of
the midparental height
8 cm
* Target (midparental) height of a child =
* Mean parental height + 6.5 cm for boys
* Mean parental height – 6.5 cm for girls
Bone Age
- Radiograph of the left hand & wrist
- Atlas of Skeletal Maturity, Greulich & Pyle
- Delayed or advanced bone age is NOT diagnostic
of any specific disease - Skeletal maturation determines remaining
growth potential - Allows prediction of adult height
Normal vs. Pathologic Short Stature
Normal: Familial short stature, constitutional growth delay
Pathologic: Growth hormone deficiency,
Intrauterine growth restriction, Short stature associated w/ syndromes, Achondroplasia
Familial Short Stature growth
- Normal birth weight & length in the first 2 years of life
- Linear growth velocity decreases as they near their genetically determined percentile
- Once the target percentile is reached, Resumes normal linear growth parallel to the growth curve, Usually 2 to 3 years old
______ are consistent with chronologic age
Skeletal maturation & timing of puberty
Constitutional Growth Delay
● Growth pattern similar to those with familial short stature EXCEPT
* Children follow a growth percentile that is below what is expected
based on parental heights
* Delay in skeletal maturation & the onset of puberty
● Growth continues beyond the time the average child stops growing
* Final height is appropriate for target height
We usually refer to these patients as being “late bloomers”
Constitutional Growth Delay
Growth Hormone Deficiency
Anterior Pituitary Gland → Human Growth Hormone (GH)
* Secretion stimulated by Growth Hormone Releasing Hormone (GHRH)
* Secretion inhibited by somatostatin
* GH is secreted in a pulsatile pattern (testing is problematic)
Growth hormone deficiency (GHD) is characterized by _____
decreased growth
velocity and delayed skeletal maturation in the absence of other explanations
____ is the MOST COMMON deficiency state
Idiopathic GHD
Infants with GHD typically have ____
normal birth weight w/ slightly reduced
length
Common 1st step evaluating for GHD
Serum concentrations of IGF-1 reasonably correlate to GH secretion & action in an adequately nourished child
Physical Exam Findings of GHD
- Hypoglycemia: Often associated with pituitary deficiencies
- Microphallus: Newborn males with gonadotropin & GH deficiency
- Many GH deficient children have excess truncal adiposity
- Isolated GHD & hypopituitarism may be unrecognized until late in infancy or childhood
Imaging that should be done to patients with GHD
All patients diagnosed with GHD should have an MRI of the hypothalamus and
pituitary gland to evaluate for a tumor prior to starting therapy
Growth Hormone Deficiency Treatment
- Subcutaneous Recombinant GH
- SQ daily injection
Expensive
Who is GH deficiency treatment indicated for
- Chronic renal failure
- Girls with Turner syndrome
- Prader-Willi syndrome
- Noonan’s syndrome
- Children born small for gestational (SGA) who fail to demonstrate catch-up growth by age 4
- Children with idiopathic short stature: Final height ~5–7 cm taller in this population
SGA infants
- Birth weight and/or length <3rd
percentile - Includes constitutionally small
infants & infants with IUGR
If mild SGA/IUGR and no fetal abnormalities, may exhibit catch-up growth during the _____
first 3 years
Small for Gestational Age/Intrauterine Growth Restriction causes
- Poor maternal environment
- Intrinsic fetal abnormalities
- Congenital infections
- Fetal malnutrition
In contrast to children with constitutional growth delay, SGA/IUGR have _____
skeletal maturation that corresponds to chronologic age or is only mildly delayed.
Short stature is associated with many syndromes, including:
- Turner Syndrome
- Prader-Willi Syndrome
- Down Syndrome
Any girl with unexplained short stature for family → _____
Chromosomal evaluation (turner syndrome)
Most common form of inherited disproportionate short stature
Achondroplasia (Dwarfism)
* Autosomal dominant
Etiology of Achondroplasia (Dwarfism)
- Autosomal dominant: 80% of cases result from new mutations.
- Pathogenic variants in the fibroblast
growth factor receptor 3 (FGFR3)
gene - Mutation disrupts chondrocyte
proliferation & differentiation,
disrupting growth plate structure
Clinical presentation Achondroplasia (Dwarfism)
- Disproportionate short stature
- Short limbs w/ redundant skin folds
- Macrocephaly
- Normal-sized trunk
- Limited elbow extension
- Genu varum
- Large head with frontal bossing (rounded prominence)
- Midface hypoplasia
- Trident configuration of hands
- Thoracolumbar gibbus (kyphosis) in infancy
- Exaggerated lumbar lordosis
Diagnosis of Achondroplasia (Dwarfism)
- Prenatal ultrasound: fetus with short stature & limb foreshortening, Macrocephaly
- Imaging: X-ray & baseline MRI or CT of brain
- Genetic testing: Fibroblast growth factor receptor-3 (FGFR3) gene mutations confirm diagnosis
Achondroplasia (Dwarfism) complications
- Speech development problems
- Teeth crowding
- Sleep Apnea
- Pneumonia
Psychosocial Short Stature
(Psychosocial Dwarfism)
- Growth impairment associated with
emotional deprivation - Under-nutrition probably plays a
role as well
Is GH therapy used in Psychosocial Short Stature?
- GH secretion in children with
psychosocial short stature is
diminished - GH therapy is usually not
beneficial
How can psychosocial short stature be improved?
A change in the psychological
environment at home improves:
* growth
* GH secretion
* personality
* eating behaviors
Growth Hormone Excess
*Excessive GH secretion is rare & generally associated with a
functioning pituitary adenoma
*GH excess leads to gigantism → if the epiphyses are open (before puberty)
*GH excess leads to acromegaly → if the epiphyses are closed (After puberty)
Precocious Puberty
Tall stature for age or rapid growth
*Typically associated with early signs of puberty & advanced bone age
*Patients can be tall for age, but they do not achieve a taller final
height than would be genetically & phenotypically expected
History workup for growth
- The upper limit of acceptable height in both sexes has increased over time
- Concerns about excessive growth in girls are less frequent than in the past
- History of chronic illness
- Medications
- Birth weight & height, pattern of growth since birth
- Family history & family growth patterns, growth curves
Physical exam for assessing growth
- Height, weight, head circumference
- Pubertal (Tanner) stage, & assessment of skeletal maturation allow estimation
of final adult height - Dysmorphic features, body segment proportion, & psychological health.
- Child with poor weight gain as the primary disturbance, a nutritional
assessment is indicated.
