BACKGROUND Genetic diversity of three polymorphic markers in the phenylalanine hydroxylase (PAH) gene region including PvuII (a), PAHSTR and MspI were investigated. METHODS Unrelated individuals (n=139) from the Iranian populations were genotyped using primers specific to PAH gene markers including PvuII(a), MspI and PAHSTR. The amplified products for PvuII(a), MspI were digested using the ap...

We introduce a stepwise approach for family-based designs for selecting a set of markers in a gene that are independently associated with the disease. The approach is based on testing the effect of a set of markers conditional on another set of markers. Several likelihood-based approaches have been proposed for special cases, but no model-free based tests have been proposed. We propose two type...

Psoriasis is a chronic skin disorder with multifactorial etiology. In a recent study, we reported results of a genome-wide scan on 46 French extended families presenting with plaque psoriasis. In addition to unambiguous linkage to the major susceptibility locus PSORS1 on Chromosome 6p21, we provided evidence for a susceptibility locus on Chromosome 20p13. To follow up this novel psoriasis susce...

BPD_28D (O2 dependency at 28 days of life) and BPD_36W (O2 dependency at 36 wks post-menstrual age) are diseases of prematurely born infants exposed to mechanical ventilation and/or oxygen supplementation. In order to determine whether genetic variants of surfactant proteins (SPs-A, B, C, and D) and SP-B-linked microsatellite markers are risk factors in BPD, we performed a family based associat...

MOTIVATION In recent years, there has been an increasing interest in using common single-nucleotide polymorphisms (SNPs) amassed in genome-wide association studies to investigate rare haplotype effects on complex diseases. Evidence has suggested that rare haplotypes may tag rare causal single-nucleotide variants, making SNP-based rare haplotype analysis not only cost effective, but also more va...

Missing data occur in genetic association studies for several reasons including missing family members and uncertain haplotype phase. Maximum likelihood is a commonly used approach to accommodate missing data, but it can be difficult to apply to family-based association studies, because of possible loss of robustness to confounding by population stratification. Here a novel likelihood for nucle...

Objective(s): Mutations in the UGT1A1 gene are responsible for hyperbilirubinemia syndromes including Crigler-Najjar type 1 and 2 and Gilbert syndrome. In view of the genetic heterogeneity and involvement of large numbers of the disease causing mutations, the application of polymorphic markers in the UGTA1 gene could be useful in molecular diagnosis of the disease. Materials and Methods: In the...

OBJECTIVE Autism spectrum disorders (ASDs) are a group of early childhood-onset neurodevelopmental disorders characterized by deficits in social interaction and language skills, and repetitive behaviors. Brain-derived neurotrophic factor (BDNF) plays a critical role in the differentiation of normal neuronal cells during embryonic and postnatal neuronal development through its neurotrophic effec...

BACKGROUND Endophenotypes reflect more proximal effects of genes than diagnostic categories, hence providing a more powerful strategy in searching for genes involved in complex psychiatric disorders. There is strong evidence suggesting the P3 amplitude of the event-related potential (ERP) as an endophenotype for the risk of alcoholism and other disinhibitory disorders. Recent studies demonstrat...

As genome-wide association studies (GWAS) are becoming more popular, two approaches, among others, could be considered in order to improve statistical power for identifying genes contributing subtle to moderate effects to human diseases. The first approach is to increase sample size, which could be achieved by combining both unrelated and familial subjects together. The second approach is to jo...