Abstract
Purpose: :
The retinas of patients with AMD contain deposits known as drusen. These deposits contain lipids and proteins which accumulate in the layer called Bruch’s membrane. Drusen components provide a list of candidate genes for the genetic analysis of this degenerative eye disease. One such constituent is an acute phase protein called serum amyloid P component (APCS), whose gene is located at 1q21. We propose to investigate whether the coding region of this two exon gene contains any polymorphisms which may confer a predisposition to AMD.
Methods: :
200 AMD patients and 200 controls from a UK cohort were analysed by two different mutation scanning techniques. The APCS gene was investigated by amplifying 6 PCR fragments prior to analysis by both single stranded conformational polymorphism (SSCP) and high resolution melt (HRM) analysis. All fragments displaying a mobility shift by either screening method were DNA sequenced in order to discern the mutation involved, and allowed comparison between the two analyses.
Results: :
Initial results reveal two previously described mutations within the APCS gene in this cohort. A non-synonymous polymorphism within exon 1 (P4S), and a synonymous polymorphism (V144V) in exon 2, both of which are class 1 single nucleotide polymorphisms (SNPs) with a change in melting temperature (Tm) greater than 0.5°C.
Conclusions: :
The two analytical methods employed detected both of the polymorphisms described. Further studies are underway to establish which mutation scanning method proves to be the most sensitive, reliable and cost effective.
Keywords: age-related macular degeneration • mutations • drusen