Congenital nephrotic syndrome, Finnish type (CNF or NPHS1), is an autosomal recessive disease characterized by massive proteinuria and development of nephrotic syndrome shortly after birth. The disease is most common in Finland, but many patients have been identified in other populations. The disease is caused by mutations in the gene for nephrin which is a key component of the glomerual ultrafilter, the podocyte slit diaphragm. A total of 30 mutations have been reported in the nephrin gene in patients with congenital nephrotic syndrome worldwide. In the Finnish population, two main mutations have been found. These two nonsense mutations account for over 94% of all mutations in Finland. Most mutations found in non-Finnish patients are missense mutations, but they include also nonsense and splice site mutations, as well as deletions and insertions. This mutation update summarizes the nature of all previously reported nephrin mutations and, additionally, describes 20 novel mutations recently identified in our laboratory.

The mu1 opioid receptor gene, OPRM1, has long been a high-priority candidate for human genetic studies of addiction. Because of its potential functional significance, the non-synonymous variant rs1799971 (A118G, Asn40Asp) in OPRM1 has been extensively studied, yet its role in addiction has remained unclear, with conflicting association findings. To resolve the question of what effect, if any, rs1799971 has on substance dependence risk, we conducted collaborative meta-analyses of 25 datasets with over 28,000 European-ancestry subjects. We investigated non-specific risk for “general” substance dependence, comparing cases dependent on any substance to controls who were non-dependent on all assessed substances. We also examined five specific substance dependence diagnoses: DSM-IV alcohol, opioid, cannabis, and cocaine dependence, and nicotine dependence defined by the proxy of heavy/light smoking (cigarettes-per-day > 20 versus ≤ 10). The G allele showed a modest protective effect on general substance dependence (OR = 0.90, 95% C.I. [0.83–0.97], p-value = 0.0095, N = 16,908). We observed similar effects for each individual substance, although these were not statistically significant, likely because of reduced sample sizes. We conclude that rs1799971 contributes to mechanisms of addiction liability that are shared across different addictive substances. This project highlights the benefits of examining addictive behaviors collectively and the power of collaborative data sharing and meta-analyses.

Abstract. Nephrin, an essential component of the glomerular ultrafilter, the slit diaphragm, has also been found to be expressed in the central nervous system and pancreas. This study examined the regulation of the nephrin gene by analyzing the expression of different length nephrin promoter-lacZ reporter constructs in transgenic mice. An upstream segment between Ϫ4 kb and Ϫ4 bp was shown to be sufficient for driving expression in all three tissues. Surprisingly, a 5.7-kb construct lacking the transcription initiation site and the immediate upstream region of the gene could drive expression in the central nervous system. This led to the identification of a novel, alternatively used exon 1B located 1871 bp upstream of the ATG codon of the previously known first exon, now termed exon 1A. The existence and functionality of exon 1B was verified in nephrin knockout mice in which exon 1A is deleted. Deletion of exon 1B and its immediate surrounding sequence, introduced in the 4-kb promoter-lacZ reporter construct, abolished the expression of the transgene in pancreas and spinal cord but not in kidney and brain in transgenic mice. Analysis of five promoter-reporter gene constructs showed that regulatory elements driving expression encoded by exon 1A in kidney and brain are localized in the region between Ϫ4 kb and 2.1 kb.

The adiponectin promoter polymorphism rs266729 is associated with gestational diabetes. The minor G allele appears to confer protection against pregnancy-related diabetes mellitus. This effect is probably due to the influence of the variant on the adiponectin transcription regulation during gestation.