Endocrinology Flashcards
MEN1
Pituitary, Pancreatic Islet Cell, Parathyroid
Mutation in the MEN1 Tumour surpressor Gene
MEN2A
Medullary Thyriod Ca (C cells), Parathyroid and Pheochromocytoma.
RET mutation(rearranged during transfection)
Autosomal Dominant Inheritance
MEN2B
Medullary Thyroid Ca, Pheochromocytoma in association with a marfanoid habitus, mucosal neuromas, and intestinal autonomic ganglion dysfunction leading to megacolon
Von Hippel-Lindau (VHL)
Mutation is associated with renal cell Ca, pheochromocytoma, retinal angioma and haemangioblastoma.
Action of FGF23
- FGF23 acts on the proximal renal tubule to inhibit renal tubular sodium-phosphate transporter (NPT2a) which reduces Phosphate resorption.
- Inhibits 1-alpha-reductase in the kidney, which reduced 1-25 Vit D
Stimulus for FGF23 production by Osteocytes
High Phosphate
Most Common Type of MODY
MODY 3
- Autosomal DOMINANT
- due to mutation of HNF-1 gene
- Very sensitive to sulfonylurea
Hormones the STIMULATE apatite
Only 3:
- Ghrelin
- Neuropeptide Y
- Agouty-related peptide
The remainer all INHIBIT food intake
Type 1 Amiodorone Induced Thyrotoxicosis
Idoine load leads to excess prodution.
- Usually in peope with Graves disease or thyroid nodules.
- Treat with thionamide
Type 2 Amiodarone Induced Thyrotoxicosis
Thyroiditis
- Stop amiodarone
- Treat with Glucocorticoid
Effects of Pregnancy on Thyroid Function:
- increased thyroxine binding globulin caused by oestrogen.
- Increase T3/T4 levels by 40-50% to compensate.
- BHCG stimulates TSH receptor, and therefore TSH is often suppressed during first trimester.
- Hypothyroidism increases risk of poor foetal outcome.
- Therefore:
- Pregnant women need to increase levothyroxine levels by 30%
- Treat subclinical hypothyroidism TSH >2.5
- In at risk patients (TPO positive, history of thyroid problems), measure TSH regularly during pregnancy.
