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Most tall children are normal, and their stature is linked to
genetic background and an optimal environment for growth. Tall stature
is concerning only if a child’s tallness is inappropriate
for parental height or when linear growth velocity accelerates inappropriately.
A number of endocrine and nonendocrine disorders cause excessive
linear growth during childhood and adolescence (Table
524-1). Endocrine causes of accelerated growth include growth
hormone (GH) excess or acromegaly; thyrotoxicosis; excess androgenic
hormones, as in congenital adrenal hyperplasia and virilizing tumors;
and sexual precocity. The latter disorders are readily apparent
on physical examination because of accompanying signs of androgen
excess or sexual maturation. Adolescents with hypogonadotropic hypogonadism
can also be tall and have a eunuchoid habitus. Other clinical entities
that can cause an increase in absolute height or accelerated height
velocity include obesity, Marfan syndrome, homocystinuria, total
lipodystrophy, neurofibromatosis, and chromosomal abnormalities
such as Klinefelter syndrome, and 48XXYY and 47XYY syndromes.
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When the prediction of adult height for a girl exceeds 183 cm
(6 feet), height is considered excessive by some families. Concern
about the final adult height of boys is rarely about overgrowth.
In general, tall children have tall parents, their body proportions
are normal, their height has been greater than the 97th percentile since
early childhood, and height velocity is within the normal range. Children
with constitutional tall stature may have augmented growth hormone
(GH) responses to some stimuli and increased levels of insulinlike
growth factor I (IGF-I).1,2
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Treatment of excessively tall girls is a therapeutic dilemma
for pediatricians and endocrinologists. Considerable data suggest
that high-dose estrogen therapy markedly restricts final height
to less than predicted. The vagaries of height prediction and the
ever-present risk of dangerous long-term side effects of hormonal therapy dictate
careful consideration of each patient’s clinical state,
self-image, and desire for treatment. The use of high-dose estrogen
in otherwise normal children must be weighed against the known (and
unknown) toxicity of such therapy,3-9 including
nausea, weight gain, edema, and hypertension. Other potential problems,
such as thromboembolism, cystic hyperplasia of the breast, endometrial
hyperplasia, and cancer, have not been definitively related to estrogen ...