Scientific background:

Summary: Nephrin forms the slit diaphragm between podocytes' foot processes. Mutations of the gene cause an autosomal recessive disease, the congenital steroid resistant nephrotic syndrome of the Finnish type.

Molecule: Nephrin consists of 3 domains. Intracellular and transmembrane domains are only short. The 35nm-long extracellular domain contains a proximal fibronectin type III-like motif and 8 distal IgG-like motifs. Extracellular protein chains from adjacent foot processes are stretched out towards each other, interact in the middle, and form the slits, so important to the filtering function of the glomeruli.
   With a tyrosine residue phosphorylated by tyrosine kinases (Src, Fyn), the intracellular domain plays an important role in signal transduction.

Methodology:

	clinical test	Method		Genomic sequencing of the entire coding region
		Turn-around time		25 working days
		Effort		medium
		Specimen		DNA
		Quality assessment		Internal quality control only
	All known and new missense, nonsense and splice mutations can be detected.
	clinical test	Method		Carrier testing
		Turn-around time		5 working days
		Effort		little
		Specimen		DNA
		Quality assessment		Internal quality control only
	The test is only specific about the mutation already known in this kindred.
	research test	Method		Gene dosage measurements
		Turn-around time		25 working days
		Effort		25 working days
		Specimen		DNA
		Quality assessment		Internal quality control only
	Of the gene rearrangements, this method is useful to detect large deletions or duplications.

Literature: