A multifactorial likelihood model for MMR gene variant classification incorporating probabilities based on sequence bioinformatics and tumor characteristics: a report from the Colon Cancer Family Registry.

Mismatch repair (MMR) gene sequence variants of uncertain clinical significance are often identified in suspected Lynch syndrome families, and this constitutes a challenge for both researchers and clinicians. Multifactorial likelihood model approaches provide a quantitative measure of MMR variant pathogenicity, but first require input of likelihood ratios (LRs) for different MMR variation-associated characteristics from appropriate, well-characterized reference datasets. Microsatellite instability (MSI) and somatic BRAF tumor data for unselected colorectal cancer probands of known pathogenic variant status were used to derive LRs for tumor characteristics using the Colon Cancer Family Registry (CFR) resource.

Blimp1 regulates development of the posterior forelimb, caudal pharyngeal arches, heart and sensory vibrissae in mice.

The zinc-finger transcriptional repressor Blimp1 (Prdm1) controls gene expression patterns during differentiation of B lymphocytes and regulates epigenetic changes required for specification of primordial germ cells. Blimp1 is dynamically expressed at diverse tissue sites in the developing mouse embryo, but its functional role remains unknown because Blimp1 mutant embryos arrest at E10.5 due to placental insufficiency.

Regulation of the Atm promoter in vivo.

While ATM, the protein defective in the human genetic disorder ataxia-telangiectasia (A-T), is primarily activated as a preexisting protein by radiation, there is also evidence that expression of the protein can be regulated at the transcriptional level. Activation of the ATM promoter by ionizing radiation has been reported only in quiescent cells in culture. To investigate how the Atm promoter is regulated in vivo, we generated transgenic mice that express the luciferase reporter gene under the control of the murine Atm promoter.

Tyrosinase-Cre mice for tissue-specific gene ablation in neural crest and neuroepithelial-derived tissues.

This study describes the derivation of two new lines of transgenic mice that express Cre recombinase under the control of tyrosinase transcriptional elements. To determine the suitability of the Tyrosinase-Cre transgene for tissue-specific gene ablation studies, a fate map of Cre expression domains was determined using the Z/AP reporter strain. It was shown that Cre-expressing cells contribute to a wide array of neural crest and neuroepithelial-derived lineages.

Pex13 inactivation in the mouse disrupts peroxisome biogenesis and leads to a Zellweger syndrome phenotype.

Zellweger syndrome is the archetypical peroxisome biogenesis disorder and is characterized by defective import of proteins into the peroxisome, leading to peroxisomal metabolic dysfunction and widespread tissue pathology. In humans, mutations in the PEX13 gene, which encodes a peroxisomal membrane protein necessary for peroxisomal protein import, can lead to a Zellweger phenotype. To develop mouse models for this disorder, we have generated a targeted mouse with a loxP-modified Pex13 gene to enable conditional Cre recombinase-mediated inactivation of Pex13.