Growth and Puberty Disorders Flashcards
differentiate between short stature and growth failure
Short stature = height >2SD below the mean for age and gender or >2SD below mid-parental height
Growth failure = abnormally slow growth velocity or crossing 2 percentile lines on the growth chart
What is the relationship betwen short stature and growth failure?
** Short stature and growth failure frequently but not always occur together.
For example, a healthy child of short parents will typically have short stature but not growth failure: He/she will grow at a normal growth velocity towards a lower genetic potential.
Conversely, a child of very tall parents can have growth failure but still be taller than the cut-off for short stature of the general population.
which growth chart pattern is below?
short stature
Which growth chart pattern is below?
failure to thrive
Which growth chart pattern is below?
constitutional growth delay
Which growth chart pattern is below?
hypothyroidism
Which growth chart pattern is below?
growth hormone deficiency
Calculate the mid-parental height (i.e. genetic growth potential) of a pediatric patient
For a girl: average of mom’s height and (dad’s height -5”)
For a boy: average of (mom’s height +5”) and dad’s height
Describe growth charts findings in a child with “failure to thrive”
deceleration of weight gain to <3% (-2SD)
or
crossing 2 major percentile lines in the first 3 years of life
describe growth charts features for a child with “constitutional growth delay”
Fall off the growth curve, (weight first, but height following shortly thereafter.)
Fall off at 2-3 years of life and then normal growth velocity following a percentile shorter than their genetic potential.
Bone age is younger than actual age
describe a growth chart pattern that would make you suspicious for an underlying endocrine disorder
Child’s height fell off the growth curve between 6-8y but her **weight % stayed the same until 8-9y. **
describe lab values found in primary hypothyroidism
low T4, resulting in high TSH
describe lab findings in central hypothyroidism
because the defect is at the level of the brain, what other hormones deficiencies might you expect to occur in thse patients?
what serious condition must you look for in these kids?
low T4 and an inappropriately low or normal TSH
central hypothyroidism often occurs concurrently with growth hormone deficiency and possibly other pituitary hormone deficiencies
brain tumor
Describe a typical growth chart pattern of a child with growth hormone deficiency
What might you expect this child to look like (and why)?
Height fell off precipitously between 3-9m with weight following a bit later. (height then weight drop off→ think endocrine)
Might expect child to be to thin, but lack of lean muscle mass gives growth hormone deficiency kids a “chubby” appearance
Describe physical findings in a child with Turner’s syndrome
The MC manifestation of all Turner syndrome patients is short stature.
They have an increased carrying angle of their arms, and due to lymphedema in utero, will have extra skin on their neck known as “webbed” neck. They may have small or retracted chins.
Due to their lack of 2 normal X chromosomes (they are XO), almost all will have ovarian failure with resulting delayed puberty
understand the clinical significance of delayed bone age in a pediatric patient who is being evaluated for a growth disorder
Growth charts are designed for the general population, which expects that a male will have a growth spurt around age 13-14y, and females at 11-12y, therefore a Constitutional Growth Delay kid will appear to fall further off the curve at that age. Their delayed skeletal maturation correlates with delayed puberty for these patients. Their delay in puberty allows them catch-up growth due to the delay in growth plate closure.
Describe a primary care W/U for a patient with growth concerns
- PLOT height and weight on all kids! (You will almost never be able to spot a poorly growing kid with just your eyes.) →Recheck height and weight if you see something odd
- Bone age (left hand and wrist) for kids 3yo+
- Screening labs:
- Metabolic panels and u/a→renal disorders.
- CBC → underlying chronic disease
- chromosomal analysis for girls→Turner syndrome
- thyroid panel
- possibly IGF-1 or IGFBP-3 (screening tests for GH deficiency)
- stim test only done in endocrinology
- inflammatory bowel disease→ a history and ESR are helpful
- celiac→ TTG and IgA are needed
describe physical changes assoc with adrenarche
pubic & axillary hair, body odor and acne in both sexes
penile enlargement in males (androgens from testes)
describe physiology assoc with gonadarche
At the onset of puberty, the hypothalamus begins to secrete GnRH in a pulsatile fashion (first at night)→ stimulates the anterior pituitary to produce luteinizing hormone (LH) and follicle stimulating hormone (FSH)→ stimulate the ovaries in girls to produce estrogen and the testes in boys to produce testosterone.
Where does estrogen come from in females? males?
How does it affect our bones?
The ovaries produce estrogen for females, and males produce estrogen by converting testosterone (made in testes) to estrogen via aromatase.
The advancement of bone age (and eventual closure of growth plates)** is due to estrogen in both sexes**.
timing of female breast development (gonadarche)
timing of menarche in girls
Female sex characteristics before what ages would be considered precocious puberty?
<7y (hispanic/AA)
<8 y (caucasian)
understand timing of male gonadarche
at what age would a boy be considered to have precocious peberty?
first is testicular growth (stimulated by FSH & LH) at ~12yo,
followed shortly by pubic hair (adrenarche),
penile enlargement ~13yo (adrenarche)
and peak height velocity (~14yo)
\*\*\*in boys \<9y is precocious puberty
describe pubic hair tanner staging
I Preadolescent no sexual hair
II Sparse, pigmented, long, straight, mainly along labia and at base of penis
III Darker, coarser, curlier
IV Adult, but decreased distribution
V Adult in quantity and type with spread to medial thighs
Describe female tanner staging for breast development
I Preadolescent
II Breast budding
III Continued Enlargement
IV Areola and papilla form secondary mound
V Mature female breasts
Describe male genitalia tanner staging
I Preadolescent
II Enlargement, change in texture
III Growth in length and circumference
IV Further development of glans penis, darkening of scrotal skin
V Adult genitalia
Define delayed puberty
(ages and physical findings)
no pubertal signs by 13 y in girls and 14y in boys
or
a lack of progression with no menarche 4 years after puberty onset in girls or incomplete genital growth in males 5 years after puberty onset.
What are some congenital, acquired & reversible causes of hypogonadotropic hypogonadism?
(AKA central hypogonadism, when the HPG axis is not working due to low GnRH or LH/FSH)
- Temporary: Constitutional growth delay
- Genetic syndromes: Prader-Willi syndrome, Kallman syndrome
- Pituitary or hypothalamic tumors, cranial irradiation or infection
- Functional: anorexia or malnutrition, excessive exercise, hyperprolactinemia and hypothyroidism.
**The central hypogonadism is reversible when the underlying condition is treated.
Hx and PE findings with Prader-Willi syndrome:
infancy→weak muscle tone (hypotonia), feeding difficulties, poor growth, and delayed development
childhood→insatiable appetite, which leads to chronic overeating (hyperphagia) and obesity
**mild to moderate intellectual impairment and learning disabilities, behavioral problems (temper outbursts, stubbornness, and compulsive behavior such as picking at the skin), sleep abnormalities
PE: narrow forehead, almond-shaped eyes, and a triangular mouth; short stature; and small hands and feet, underdeveloped genitals.
**Puberty is delayed/incomplete, and most are infertile
Hx and PE findings specific to Kallman syndrome
Kallmann syndrome is a condition characterized by delayed or absent puberty **(hypogonadotropic hypogonadism) **and an impaired sense of smell
Hx and PE findings distinguishing Turner syndrome from other causes of hypogonadotropic hypogonadism
FEMALES. short stature, which becomes evident by about age 5
webbed neck, a low hairline at the back of the neck, puffiness or swelling (lymphedema) of the hands and feet, skeletal abnormalities, or kidney problems.
One third to one half of individuals with Turner syndrome are born with coarctation of the aorta or abnormalities of the aortic valve .
normal intelligence
Hx and PE findings that distinguish Klinefelters syndrome (XXY) from other genetic causes of hypogonadotropic hypogonadism:
A shortage of testosterone →delayed or incomplete puberty, gynecomastia, reduced facial and body hair, infertility.
Some affected individuals also have genital differences including undescended testes (cryptorchidism), the opening of the urethra on the underside of the penis (hypospadias), or micropenis.
adults→ taller than their peers
Children → learning disabilities and delayed speech and language development. They tend to be quiet, sensitive, and unassertive
Design an evaluation for delayed puberty
- History: cranial irradiation, chemotherapy/other radiation, family hx of genetic disorders, exercise/nutrition/eating disorders, previous concerns about growth, sense of smell
- Height and growth rate: puberty onset in girls typically results in a linear growth spurt, as does mid-late puberty in males
- Bone age: Delayed puberty will result in a delayed bone age
- Labs: gonadotropins, testosterone, estradiol (may consider TSH, T4, prolactin, CBC, ESR, BMP)
- if the GnRH generator (hypothalamus) is functioning, the FSH & LH will be up…….FSH & LH will be low if the defect is at the level of the hypothalamus
- Rule out hypothyroidism and prolactinemia as a cause of hypogonadotropic hypogonadism
- Karyotype: If FSH & LH are elevated, indicating the is functioning, then get a karotype to look for sex chromosome defects
Describe characteristics of incomplete precocious puberty
=NOT associated with growth acceleration or bone age advancement, but f/u q 4months
- premature thelarche
- premature adrenarce
premature thelarche→ onset of breast development without other pubertal changes (breast development progresses very slowly or waxes and wanes in size)
- before 2yo is d/t greater ovarian hormone production
- older than 2yo is d/t periodic fluctuations in the HPG axis with temporary FSH secretion
- can get bone age/ estrodiol level if over 3yo
Premature adrenarche →pubic and/or axillary hair, with no evidence of gonardarche,
- boys <9y
- white girls <8y
- AA/Latina girls <7y
what is the relative risk of CNS abnormality in male and females with precocious puberty?
In girls, the chance of brain tumor is 5%, in boys 50%.
List some of the relatively benign causes of peripheral precocious puberty in females:
ovarian cysts
exogenous estrogens (lavender products and tea tree oil)
