Thousands of induced germline mutations affecting immune cells identified by automated meiotic mapping coupled with machine learning

Forward genetic studies use meiotic mapping to adduce evidence that a particular mutation, normally induced by a germline mutagen, is causative of a particular phenotype. Particularly in small pedigrees, cosegregation of multiple mutations, occasional unawareness of mutations, and paucity of homozygotes may lead to erroneous declarations of cause and effect. We sought to improve the identification of mutations causing immune phenotypes in mice by creating Candidate Explorer (CE), a machine-learning software program that integrates 67 features of genetic mapping data into a single numeric score, mathematically convertible to the probability of verification of any putative mutation-phenotype association. At this time, CE has evaluated putative mutation-phenotype associations arising from screening damaging mutations in ∼55% of mouse genes for effects on flow cytometry measurements of immune cells in the blood. CE has therefore identified more than half of genes within which mutations can be causative of flow cytometric phenovariation in Mus musculus The majority of these genes were not previously known to support immune function or homeostasis. Mouse geneticists will find CE data informative in identifying causative mutations within quantitative trait loci, while clinical geneticists may use CE to help connect causative variants with rare heritable diseases of immunity, even in the absence of linkage information. CE displays integrated mutation, phenotype, and linkage data, and is freely available for query online.

The effect of an antiserotonin agent pizotifen on platelet aggregability in migraine patients

In 19 patients who were suffering from frequent migraine attacks and were treated with pizotifen, spontaneous platelet aggregation (SPA) was measured prior to treatment and at the second, fourth and sixth month of treatment. A Migraine Headache Score (MHS) was employed for evaluation of the "activity" of migraine in the same periods. Spontaneous platelet aggregation was also measured in a control group of 40 migraine-free subjects. Prior to treatment the mean value of SPA in the group of migraine patients was four times higher than in the control group. In the 19 migraine patients the mean value of SPA in the second month of treatment showed a 48% reduction when compared with the mean value of SPA prior to treatment. Clear clinical improvement was observed during the treatment, and the average MHS in the second month of treatment showed a 77% reduction compared with the average MHS prior to treatment. The increased rate of SPA prior to treatment and the close correlation between the SPA rate and "activity" of migraine during the treatment suggest that increased platelet aggregability may play a significant role in the pathogenesis of migraine.

Migraine attacks and increased platelet aggregability induced by oral contraceptives

A case where common and complicated migraine attacks appeared during the course of oral contraception is reported. The attacks of complicated migraine also continued to appear after the contraceptives were stopped. Increased platelet aggregability was found at the time when the complicated migraine attacks were frequent and, therefore, treatment with dipyridamole and aspirin was given. At the time when a gradual reduction of the platelet aggregability was observed, a decrease in the frequency, and eventual disappearance of the complicated migraine attacks was simultaneously seen. Causal relationship between increased platelet aggregability and complicated migraine attacks is suggested.

Transient ischaemic attacks and increased platelet aggregability associated with oral contraceptives. Treatment with dipyridamole and aspirin

A 24-year old woman after using birth control pills for two months began to suffer from frequent migraine-like attacks, which turned eventually into typical transient ischaemic attacks (TIAs). A significant increase in spontaneous platelet aggregation was found, and combined treatment with dipridamole and aspirin was started. After two months of treatment spontaneous platelet aggregation rate fell to normal limits and TIAs disappeared. A causal relationship between increased platelet aggregability and TIAs is supposed.