Endocrinal causes of short stature

Endocrinal causes of short stature

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1-GH deficiency:

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—            a)congenital: short stature,obesity,immature high pitched voice ,delayed skeletal maturation, higher incidence of hyperlipedemia,microphallus(if associated with decrease GnRH),hypoglycemia and seizures may occure,intellgence is normal.

ttt:exogenous hGH but some develop antibodies those are reported to benefit from IGF-1

b)acquired:onset in late childhood

—            causes:hypothalamic,pituitary tumors,empty sella syndrome, cranial irradiation as in ttt of tumors or leukemia.

—            c)laron's syndrome(GH resistance) receptor or postreceptor defect

—            GH is high

—            IGF-1 is low

—            Intellectual impairment

—            ttt:recombinant DNA derived IGF-1

—            Diagnosis of GH deficiency:

—            Inadequate rise of serum GH after provocative stimuli

—            as basal GH may be low in children

—            GH is released in episodic pulses

—           if GH is elevated above 10 μg/ml after test GH deficiency is eliminated.—            

Serum GH should rise after:

—            1)10 minutes of vigorous exercise

—            2)arginin infusion

—            3)levodopa or clonidine orally.

—            4)insulin induced hypoglycemia (0.1 unit /kg)after overnight fasting.

—            ttt:GH (somatotropin)is available.

—            GHRH in episodic doses—restores GH.

—            IGF-1 in laron’s Syndrome 

—            2)psychological dwarfism: functional hypopituitarism in ignored or emotionally deprived children.

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3) Hypothyroidism: growth rate and skeletal developmental delay: congenital hypothyroidism if untreated→mental retardation, screened by T4, TSH. In late onset type intelligence is normal.

—            4) Cushing syndrome: excess glucocorticoids in childhood →decrease growth even before other signs of Cushing.

—            Causes:

—            Bilateral adrenal hyperplasia ---due to increase ACTH

—            Iatrogenic

—            Adrenal adenoma,carcinoma.

—            Diagnosis:urinary cortisol,dexamethasone  suppression test ,CRH test ,MRI pituitary.

ttt:transsphenoidal microadenomectomy

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5) pseudohypoparathyroidism:increased PTH,decreased Ca and increased ph .

—            Child is short, round face, short 4^th  and 5^th metacarpals; it is due to receptor defect.

—            ttt: vit D, exogenous Ca and ph binding agents.

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6)Vit D metabolism disorders:

—            Rickets

—            Inadequate vit D

—            Decrease exposure to sunlight

—            Malabsorption

—            Renal and hepatic diseases

—            Anti convulsive therapy

—            Decreased Ca, decreased ph level, increased alkaline phophatase

—            Hereditary vit D def. Rickets:

—            Renal 25-OHD-1 hydroxylase(decrease)

—            Receptor defect

—            Renal tubular acidosis

—            ttt:vit D, ph replacement

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7) Diabetes mellitus: short stature in uncontrolled patients.IGF1 is low in uncontrolled pts.

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—            8) diabetes insipidus: there is poor caloric intake.