Nephritic Syndrome-Alport's Syndrome & Thin Babsement membrane

Question 1

What is Alport’s syndrome?

Answer 1

This disease is the result of mutations in the genes for one of the alpha chains of collagen type IV (the alpha5 chain)

Question 2

What is the result of the mutation in the alpha5 chain in collagen type IV?

Answer 2

Results in defective heterotrimer assembly and defective basement membranes.

Question 3

What other anatomical structures besides the kidney are defective in Alport’s syndrome?

Answer 3

Lens and cochlea

Question 4

What other symptoms would a patient with Alport’s present with?

Answer 4

Nerve deafness, and lens disorders

Question 5

How would the GBM appear on EM in Alport’s

Answer 5

The GBM would appear thin or attenuated or may show several alternating layers of lamina rara and lamina densa in a configuration describes as “BASKET WEAVE”

Question 6

What is the most common mode of inheritance in Alport’s?

Answer 6

X-Linked

Question 7

How else is Alport’s inherited?

Answer 7

AR

Question 8

What do carriers tend to have in Alport’s?

Answer 8

Persistent mild hematuria. Usually benign

Question 9

What is thin basement membrane disease?

Answer 9

A group od autosomal dominant diseases with defects in Alpha-3 or Alpha-4 of type IV collagen causeing reduction of the GBM to about half its normal thickness

Question 10

How do patients with Thin basement membrane disease present?

Answer 10

Persistent microscopic hematuria and a benign clinical course (unless homozygous or complicated by second glomerular disease)