Diabetes & defects in sulin metabolism Flashcards
What is the mode of inheritance of Leprechaunism (Donohue syndrome)?
Autosomal recessive
Clinical appearance of leprechaunism
Elfin facial apearance
Growth retardation
Abscence of subcutaneous fat
Decreased muscle mass
What causes leprechaunism?
Mutations in the gene for insulin receptor causing severe insulin resistance
Which insulin metabolism defect is acanthosis nigricans seen in?
Rabson Mendenhall syndrome
How does DKA occur?
When insulin is not present cells fail to recieve enough glucose so break down fatty acids
this leaves an excess of acetyl-CoA which is converted to ketone bodies
Accumulation of ketones leads to acidosis
High glucose excretion causes dehydration exacerbating acidosis
How is LADA diagnosed?
Presence of elevated levels of pancreatic autoantibodies in patients with ‘recently diagnosed’ diabetics who do not require insulin
What age does LADA typically present?
25 - 40 y/o
What causes MODY?
Defective glucose sensing in the pancreas and/or loss of insulin secretion (monogenic)
Mutations in what genes can cause MODY?
Glucokinase (GCK/MODY2)
Several transcription factors
When does MODY from a GCK defect tend to present compared to transciption factors?
GCK - birth
Transcription factors - adolescence
What is the pathogenesis of type 1 diabetes?
B cell failure + absolute insulin deficiency
What is the pathogenesisof type 2 diabetes?
Hyperinsulinaemia + insulin resistance receptor not as responsive to glucose
Clinical presentation of type 1 diabetes?
Young Usually lean Acute onset Polyuria Polydipsia Weight loss Ketouria +/- metabolic acidosis
Clinical presentation of type 2 diabetes?
Middle-aged/elderly Usually obese Insidious onet Ketonuria minimal or absent Evidence of microvascular disease (20%) `
Which pancreatic diseases can cause diabetes?
Chronic or recurrent pancreatitis
Haeochromatosis
Cystic fibrosis
