A complex selection signature at the human AVPR1B gene

<p>Abstract</p> <p>Background</p> <p>The vasopressin receptor type 1b (<it>AVPR1B</it>) is mainly expressed by pituitary corticotropes and it mediates the stimulatory effects of AVP on ACTH release; common <it>AVPR1B </it>haplotypes have been involved in mood and anxiety disorders in humans, while rodents lacking a functional receptor gene display behavioral defects and altered stress responses.</p> <p>Results</p> <p>Here we have analyzed the two exons of the gene and the data we present suggest that <it>AVPR1B </it>has been subjected to natural selection in humans. In particular, analysis of exon 2 strongly suggests the action of balancing selection in African populations and Europeans: the region displays high nucleotide diversity, an excess of intermediate-frequency alleles, a higher level of within-species diversity compared to interspecific divergence and a genealogy with common haplotypes separated by deep branches. This relatively unambiguous situation coexists with unusual features across exon 1, raising the possibility that a nonsynonymous variant (Gly191Arg) in this region has been subjected to directional selection.</p> <p>Conclusion</p> <p>Although the underlying selective pressure(s) remains to be identified, we consider this to be among the first documented examples of a gene involved in mood disorders and subjected to natural selection in humans; this observation might add support to the long-debated idea that depression/low mood might have played an adaptive role during human evolution.</p

Diagnostic Strategies and Algorithms for Investigating Cancer Predisposition Syndromes in Children Presenting with Malignancy

In the past recent years, the expanding use of next-generation sequencing has led to the discovery of new cancer predisposition syndromes (CPSs), which are now known to be responsible for up to 10% of childhood cancers. As knowledge in the field is in constant evolution, except for a few &ldquo;classic&rdquo; CPSs, there is no consensus about when and how to perform germline genetic diagnostic studies in cancer-bearing children. Several clinical screening tools have been proposed to help identify the patients who carry higher risk, with heterogeneous strategies and results. After introducing the main clinical and molecular features of several CPSs predisposing to solid and hematological malignancies, we compare the available clinical evidence on CPS prevalence in pediatric cancer patients and on the most used decision-support tools in identifying the patients who could benefit from genetic counseling and/or direct genetic testing. This analysis highlighted that a personalized stepwise approach employing clinical screening tools followed by sequencing in high-risk patients might be a reasonable and cost-effective strategy in the care of children with cancer

Progressive Encephalomyelitis with Rigidity and Myoclonus Associated With Anti-GlyR Antibodies and Hodgkin’s Lymphoma: A Case Report

IntroductionA 60-year-old man presented with a 6-month history of low back pain and progressive rigidity of the trunk and lower limbs, followed by pruritus, dysphonia, hyperhydrosis, and urinary retention. Brain and spinal imaging were normal. EMG showed involuntary motor unit hyperactivity. Onconeural, antiglutamic acid decarboxylase (anti-GAD), voltage-gated potassium channel, and dipeptidyl peptidase-like protein 6 (DPPX) autoantibodies were negative. CSF was negative. Symptoms were partially responsive to baclofen, gabapentin, and clonazepam, but he eventually developed severe dysphagia. Antiglycine receptor (anti-GlyR) antibodies turned out positive on both serum and CSF. A plasmapheresis cycle was completed with good clinical response. A PET scan highlighted an isolated metabolically active axillary lymphnode that turned out to be a classic type Hodgkin lymphoma (HL), in the absence of bone marrow infiltration nor B symptoms. Polychemotherapy with ABVD protocol was completed with good clinical response and at 1-year follow-up the neurological examination is normal.BackgroundProgressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare and severe neurological syndrome characterized by muscular rigidity and spasms as well as brain stem and autonomic dysfunction. It can be associated with anti-GAD, GlyR, and DPPX antibodies. All of these autoantibodies may be variably associated with malignant tumors and their response to immunotherapy, as well as to tumor removal, is not easily predictable.ConclusionProgressive encephalomyelitis with rigidity and myoclonus has already been described in association with HL, but this is the first case report of a HL manifesting as anti-GlyR antibodies related PERM. Our report highlights the importance of malignancy screening in autoimmune syndromes of suspected paraneoplastic origin