Question

Identifying associated markers/snps in a human schizophrenia GWAS would be very problematic if....

Question 4 options:

	a). There are 3 loci, each having specific “mutant” alleles, causing schizophrenia such that all 3 mutant alleles must be present in an individual to result in the phenotype under study.
	b). There are multiple independent combinations of alleles/genes and several of these combinations can each result in schizophrenia.
	c) Schizophrenia were quite common (e.g. frequency=10%) in the human population
	d). The specific alleles that are associated with the causative sequence changes for the phenotype are highly represented (>40% allele frequency) within the entire human population.
	e) -- a) and c)
	f) -- b) and d)

Answer 1

According to me it should be a and c.

Reason:

Different mutant forms of a single gene those are regulating the phenotypic character. So, it will be difficult to mark a wild type gene as they are so mutation proned. ALong with that, if the allele frequency is much higher it would be difficult to locate the wild type gene or more specifically wild type protein expressed by that gene.