Gene therapy for mtDNA-related diseases
One potential therapeutic method for treating mitochondrial diseases relies on the expression of mitochondrial genes in the nucleus. Here, Ellouze et al. use this method to generate a rat model of Leber Hereditary Optic Neuropathy (LHON). Subsequent treatment with the wild-type gene successfully rescues the disease phenotype and prevents further damage.

Methods to analyze rare variants
The current technologies in use for the identification of genetic variants associated with complex diseases focus on the concept that common variants are responsible for a small but significant risk effect. An alternative, but nonexclusive, hypothesis is that multiple rare variants are responsible for a gene"s association with a phenotype. Here, Li and Leal present techniques to identify association variants in the presence of high allelic heterogeneity.

Adaptive Evolution of the UGT2B17 CNV
To assess whether the presence of a region of CNV is due to selection versus genetic drift, Xue et al. decide to evaluate a specific CNV containing UGT2B17 using the techniques already established to detect signatures of selection at SNPs. The authors perform a number of neutrality tests, and their results suggest that the region underwent unique selective events in each of the different populations studied.

DYRK1A dosage perturbs REST levels
By examining a number of mouse Down Syndrome (DS) model cell lines, Canzonetta et al. report that the dose of DYRK1A is responsible for modulations of REST transcript levels. This relationship between DYRK1A and the REST pathway may be a crucial mechanism through which trisomy 21 causes a number of DS neuronal features.

X-linked dominant protoporphyria
Erythropoietic protoporphyria (EPP) is characterized by life-long photosensitivity and is most often caused by mutations in FECH, the gene encoding the terminal enzyme of heme biosynthesis. However, a significant number of EPP families do not carry mutations in FECH. Whatley et al. study a subgroup of these FECH-mutation-negative families who each have an unusually high level of erythrocyte protoporhyrin in its zinc chelate form, and identify deletions in ALAS2.