Dinucleotide repeat polymorphism in the proteolipoprotein (PLP) gene

We report a dinucleotide polymorphism in the first intron of the proteolipid protein (PLP) gene with a heterozygosity frequency of 0.69 useful for molecular analysis of families with X-linked neurologic disorders characterized by dysmyelination of the central nervous system, Pelizaeus-Merzbacher Disease (PMD) and X-linked Spastic Paraplegia (SPG2).     

Dinucleotide repeat polymorphism in the human ceruloplasmin gene

We have identified a GT dinucleotide repeat polymorphism in intron 14 of the human ceruloplasmin gene. Observed heterozygosity for the polymorphism is 0.84.     

Ethnic variations of a retinoblastoma susceptibility gene (RB1) polymorphism in eight Asian populations

An A → G single nucleotide polymorphism (SNP) at nucleotide 153,104 in the retinoblastoma susceptibility locus (RB1) at 13q14 was previously reported to be present only in Asians. In this study, we determined the distribution of this SNP in normal Southeast Asian populations (Chinese, Malay, Javanese, Thai, Filipino), in South Asian populations (Bangladeshi, Pakistani Pushtun and Indian) and in Chinese retinoblastoma cases and control subjects. TheRB1 SNP was present in all populations at an overall frequency of ≤0.18. Heterozygosity was higher in the Southeast Asian groups (0.14–0.34) than in the South Asian groups (Bangladeshi and Indian) (0.04–0.06). Significant differences in allele frequencies were found between the two population groups. Interestingly, our Pakistani population comprised of ethnic Pushtuns from northwest Pakistan was significantly different from the neighbouring Bangladeshi and Indian populations. No significant difference was found between Chinese case patients and control subjects. ThisRB1 SNP appears to be an ethnic variant prevalent in Southeast Asian populations and may be useful for studyingRB1 inheritance by pedigree analysis.