The first genomewide interaction and locus-heterogeneity linkage scan in bipolar affective disorder: strong evidence of epistatic effects between loci on chromosomes 2q and 6q.

We present the first genomewide interaction and locus-heterogeneity linkage scan in bipolar affective disorder (BPAD), using a large linkage data set (52 families of European descent; 448 participants and 259 affected individuals). Our results provide the strongest interaction evidence between BPAD genes on chromosomes 2q22-q24 and 6q23-q24, which was observed symmetrically in both directions (nonparametric LOD [NPL] scores of 7.55 on 2q and 7.

Molecular genetics of retinitis pigmentosa in two Romani (Gypsy) families.

Purpose: To identify the disease-causing mutations in two large Bulgarian Romani (Gypsy) pedigrees: one with autosomal dominant retinitis pigmentosa (adRP) with partial penetrance and the other with severe X-linked RP (xlRP).

Methods: Detailed clinical investigations were undertaken and genomic DNA was extracted from blood samples. DNA was analyzed by PCR amplification with gene-specific primers and direct genomic sequencing.

Genomewide scan and fine-mapping linkage studies in four European samples with bipolar affective disorder suggest a new susceptibility locus on chromosome 1p35-p36 and provides further evidence of loci on chromosome 4q31 and 6q24.

We present the findings of a large linkage study of bipolar affective disorder (BPAD) that involved genomewide analysis of 52 families (448 genotyped individuals) of Spanish, Romany, and Bulgarian descent and further fine mapping of the 1p34-p36, 4q28-q31, and 6q15-q24 regions. An additional sample of 56 German families (280 individuals) was included for this fine-mapping step. The highest nonparametric linkage scores obtained in the fine mapping were 5.

Linkage analysis in bipolar pedigrees adds support for a susceptibility locus on 21q22.

Several studies provide suggestive evidence of a susceptibility locus for bipolar disorder at chromosome 21q22-23. In an attempt to replicate these findings, we have analyzed linkage to 11 polymorphic markers from this region in 18 Bulgarian pedigrees with affective disorder. Two-point linkage analysis under assumption of homogeneity and a dominant model with reduced penetrance produced modest positive values for some of the markers tested under a 'narrow' phenotype definition, including bipolar I and II, and schizoaffective disorder.

An investigation into sub-telomeric deletions of chromosome 22 and pervasive developmental disorders.

Deletions of the sub-telomeric region of chromosome 22 have been associated with mental retardation, developmental delay, and autistic behaviors. This study investigated sub-telomeric anomalies of chromosome 22 using fluorescent in situ hybridization (FISH) probes in 82 subjects diagnosed with autism and atypical autism. No microdeletions were detected in this group.