Haplotype analysis of congenital nephrotic syndrome of the Finnish type in non-Finnish families

Congenital nephrotic syndrome of the Finnish type (CNF) has an estimated incidence of 1 in 8000 newborns in the genetically isolated population of Finland. Although the disease is most common in Finland, it occurs throughout the world in families without known Finnish origin. In the past, these authors recently localized the CNF gene to the chromosome 19q13.1 region and observed strong linkage disequilibrium to the genetic markers D19S610, D19S608, D198224, and D19S220 in Finnish families. In these Finnish families, four main CNF haplotype categories have been observed. In the study presented here, haplotype analysis was applied to several non-Finnish CNF families to determine whether the same genetic locus is involved in these families. The results of the haplotype analysis suggest linkage to the 19q13.1 chromosomal region. It was also observed that, in most cases, alleles typically found on CNF chromosomes of Finnish families are also found on CNF chromosomes of non- Finnish families from North America and Europe. In these families, the strongest association was found with marker D198608. These findings suggest that Finnish and many non-Finnish CNF cases share the same disease locus.