In the child were being diluted out in making direct comparisons of the affected versus unaffected children relative to the evidence for association when comparing the mothers. Unusual patterns of inheritance were also observed when comparing genotype-wise associations in children versus mothers suggesting that there may be a direct effect of mother’s genotype, or that there may be parent-of-origin effects, i.e. that for the child it is the origin of, and not just the combination of, alleles that is important in determining disease risk. Using a Lomitapide Mesylate log-linear method previously designed to evaluate maternal genotype and/or parent-of-origin effects in case-parent trios. The isoform without exon 10 has not been previously reported. Since there is no expressed sequence tag cDNA or RNA evidence for this spliced Benzethonium Chloride variant reported in the ENSEMBL genome database, we 
cannot be certain that this transcript is translated into a functional protein. For the known functional exon 10-containing isoform at ABCA4 we found that 4 of the 5 EBV lines that were heterozygous for genomic DNA showed monoallelic expression in cDNA for the exon 10 rs3112831 SNP. This mono-allelic expression was observed independently in multiple RNA extractions from each of which multiple cDNA preparations were made from these EBV cell lines, demonstrating that this was not due to chance events in amplification of the cDNA. Examining parental genotypes in the EBV cell bank, we determined that the paternally-derived allele is silenced for the exon10-containing isoform of ABCA4. However, given the small sample of polyclonal EBV cell lines examined we cannot state definitively that it is always the paternally-derived allele that is silenced. Hence, this could represent random choice autosomal monoallelic expression, which has recently been shown to be more common in the genome than was previously supposed. This could also account for the apparent polymorphic nature of the silencing, since a majority of genes showing random choice autosomal monoallelic expression display biallelic expression in some clonal cell lines. Since all the EBV cell lines employed here were polyclonal, imprinting currently provides the more likely explanation for the monoallelic expression we observed. We also demonstrated monoallelic expression for a SNP in exon 7 in cDNA specifically amplified for the IIB short form of COL2A1.