Mitochondrial DNA phylogeny in Eastern and Western Slavs

To resolve the phylogeny of certain mitochondrial DNA (mtDNA) haplogroups in eastern Europe and estimate their evolutionary age, a total of 73 samples representing mitochondrial haplogroups U4, HV*, and R1 were selected for complete mitochondrial genome sequencing from a collection of about 2,000 control region sequences sampled in eastern (Russians, Belorussians, and Ukrainians) and western (Poles, Czechs, and Slovaks) Slavs. On the basis of whole-genome resolution, we fully characterized a number of haplogroups (HV3, HV4, U4a1, U4a2, U4a3, U4b, U4c, U4d, and R1a) that were previously described only partially. Our findings demonstrate that haplogroups HV3, HV4, and U4a1 could be traced back to the pre-Neolithic times ( approximately 12,000-19,000 years before present [YBP]) in eastern Europe. In addition, an ancient connection between the Caucasus/Europe and India has been revealed by analysis of haplogroup R1 diversity, with a split between the Indian and Caucasus/European R1a lineages occurring about 16,500 years ago. Meanwhile, some mtDNA subgroups detected in Slavs (such as U4a2a, U4a2*, HV3a, and R1a1) are definitely younger being dated between 6,400 and 8,200 YBP. However, robust age estimations appear to be problematic due to the high ratios of nonsynonymous to synonymous substitutions found in young mtDNA subclusters.

Mitochondrial DNA variability in Slovaks, with application to the Roma origin

To gain insight into the mitochondrial gene pool diversity of European populations, we studied mitochondrial DNA (mtDNA) variability in 207 subjects from western and eastern areas of Slovakia. Sequencing of two hypervariable segments, HVS I and HVS II, in combination with screening of coding region haplogroup-specific RFLP-markers, revealed that the majority of Slovak mtDNAs belong to the common West Eurasian mitochondrial haplogroups (HV, J, T, U, N1, W, and X). However, a few sub-Saharan African (L2a) mtDNAs were detected in a population from eastern part of Slovakia. In addition, about 3% of mtDNAs from eastern Slovakia encompass Roma-specific lineages. By means of complete mtDNA sequencing we demonstrate here that the Roma-specific M-lineages observed in gene pools of different Slavonic populations (Slovaks, Poles and Russians), belong to Indian-specific haplogroups M5a1 and M35. Moreover, we show that haplogroup J lineages found in gene pools of the Roma and some Slavonic populations (Czechs and Slovaks) belong to new subhaplogroup J1a, which is defined by coding region mutation at position 8460.

Severe limb necrosis: primary thrombotic microangiopathy or “seronegative” catastrophic antiphospholipid syndrome? A diagnostic dilemma

An episode of gastroenteritis triggered severe necrosis of all extremities in a previously asymptomatic male. Hepatic and renal involvement were also manifest, while the hematological picture was one of thrombotic microangiopathic hemolytic anemia. Antiphospholipid antibodies were negative. He responded well to a combination of plasma exchange, anticoagulation (heparin), parenteral steroids, and antibiotics, as well as vasodilators (prostacycline) and hyperbaric oxygen, but died because of a cerebral hemorrhage. The differential diagnosis included thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome, or seronegative catastrophic antiphospholipid (Asherson's) syndrome. The dangers of administering such a combination of therapies with anticoagulation, as well as vasodilatation (prostacycline) and hyperbaric oxygen, are highlighted by the case report and emphasized.

Hypofibrinogenaemia caused by a novel FGG missense mutation (W253C) in the gamma chain globular domain impairing fibrinogen secretion

BACKGROUND

Inherited disorders of fibrinogen are rare and affect either the quantity (hypofibrinogenaemia and afibrinogenaemia) or the quality of the circulating fibrinogen (dysfibrinogenaemia). Extensive allelic heterogeneity has been found for all three disorders: in congenital afibrinogenaemia >30 mutations, the majority in FGA, have been identified in homozygosity or in compound heterozygosity. Several mutations have also been identified in patients with hypofibrinogenaemia; many of these are heterozygous carriers of afibrinogenaemia null mutations.

OBJECTIVE

To report the case of a patient from Slovakia diagnosed with hypofibrinogenaemia characterised by fibrinogen concentrations of around 0.7 g/l.

RESULTS

The patient was found to be heterozygous for a novel missense mutation W253C (W227C in the mature protein) in the C-terminal globular domain of the fibrinogen gamma chain. Co-expression of the W253C FGG mutant cDNA (fibrinogen Bratislava) in combination with wild-type FGA and FGB cDNAs showed that fibrinogen molecules containing the mutant gamma chain can assemble intracellularly but are not secreted into the media, confirming the causative nature of the identified mutation.

CONCLUSIONS

Current analysis of fibrinogen Bratislava indicates that the domains important for the processes of hexamer assembly and hexamer secretion should not be considered as strictly restricted to one or other fibrinogen chain.

[Mesenteric venous thrombosis probably due to hereditary thrombophilia in an 18-year-old boy]

The authors describe the case-history of an 18-year-old patient with an extensive venous mesenteric thrombosis. The case proved fatal despite repeated surgery as a result of relapsing gangrene of the small intestine with diffuse stercoral peritonitis. Thrombosis of the mesenteric veins is a rare disease and accounts only for 4 to 10% of all acute intestinal episodes. The cause of the disease is either idiopathic but more frequently it is associated with various types of coagulopathy. In this context the authors discuss etiological factors, symptoms, diagnosis as well as possible treatment of acute mesenteric venous thrombosis.