Genetic Analysis of Mingrelians Reveals Long-Term Continuity of Populations in Western Georgia (Caucasus)

To elucidate the population history of the Caucasus, we conducted a survey of genetic diversity in Samegrelo (Mingrelia), western Georgia. We collected DNA samples and genealogical information from 485 individuals residing in 30 different locations, the vast majority of whom being Mingrelian speaking. From these DNA samples, we generated mitochondrial DNA (mtDNA) control region sequences for all 485 participants (female and male), Y-short tandem repeat haplotypes for the 372 male participants, and analyzed all samples at nearly 590,000 autosomal single nucleotide polymorphisms (SNPs) plus around 33,000 on the sex chromosomes, with 27,000 SNP removed for missingness, using the GenoChip 2.0+ microarray. The resulting data were compared with those from populations from Anatolia, the Caucasus, the Near East, and Europe. Overall, Mingrelians exhibited considerable mtDNA haplogroup diversity, having high frequencies of common West Eurasian haplogroups (H, HV, I, J, K, N1, R1, R2, T, U, and W. X2) and low frequencies of East Eurasian haplogroups (A, C, D, F, and G). From a Y-chromosome standpoint, Mingrelians possessed a variety of haplogroups, including E1b1b, G2a, I2, J1, J2, L, Q, R1a, and R1b. Analysis of autosomal SNP data further revealed that Mingrelians are genetically homogeneous and cluster with other modern-day South Caucasus populations. When compared with ancient DNA samples from Bronze Age archaeological contexts in the broader region, these data indicate that the Mingrelian gene pool began taking its current form at least by this period, probably in conjunction with the formation of a distinct linguistic community.

Ancient DNA from Mesopotamia suggests distinct Pre-Pottery and Pottery Neolithic migrations into Anatolia

We present the first ancient DNA data from the Pre-Pottery Neolithic of Mesopotamia (Southeastern Turkey and Northern Iraq), Cyprus, and the Northwestern Zagros, along with the first data from Neolithic Armenia. We show that these and neighboring populations were formed through admixture of pre-Neolithic sources related to Anatolian, Caucasus, and Levantine hunter-gatherers, forming a Neolithic continuum of ancestry mirroring the geography of West Asia. By analyzing Pre-Pottery and Pottery Neolithic populations of Anatolia, we show that the former were derived from admixture between Mesopotamian-related and local Epipaleolithic-related sources, but the latter experienced additional Levantine-related gene flow, thus documenting at least two pulses of migration from the Fertile Crescent heartland to the early farmers of Anatolia.

The genetic history of the Southern Arc: A bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra-West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe.

A genetic probe into the ancient and medieval history of Southern Europe and West Asia

Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom's northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region.

Genetic diversity in Svaneti and its implications for the human settlement of the Highland Caucasus

OBJECTIVES

In this study, we characterized genetic diversity in the Svans from northwestern Georgia to better understand the phylogeography of their genetic lineages, determine whether genetic diversity in the highland South Caucasus has been shaped by language or geography, and assess whether Svan genetic diversity was structured by regional residence patterns.

MATERIALS AND METHODS

We analyzed mtDNA and Y-chromosome variation in 184 individuals from 13 village districts and townlets located throughout the region. For all individuals, we analyzed mtDNA diversity through control region sequencing, and, for males, we analyzed Y-chromosome diversity through SNP and STR genotyping. The resulting data were compared with those for populations from the Caucasus and Middle East.

RESULTS

We observed significant mtDNA heterogeneity in Svans, with haplogroups U1-U7, H, K, and W6 being common there. By contrast, ∼78% of Svan males belonged to haplogroup G2a, with the remainder falling into four other haplogroups (J2a1, I2, N, and R1a). While showing a distinct genetic profile, Svans also clustered with Caucasus populations speaking languages from different families, suggesting a deep common ancestry for all of them. The mtDNA data were not structured by geography or linguistic affiliation, whereas the NRY data were influenced only by geography.

DISCUSSION

These patterns of genetic variation confirm a complex set of geographic sources and settlement phases for the Caucasus highlands. Such patterns may also reflect social and cultural practices in the region. The high frequency and antiquity of Y-chromosome haplogroup G2a in this region further points to its emergence there.

Priapism in sickle-cell disease; incidence, risk factors and complications - an international multicentre study

OBJECTIVE

To define the incidence, risk factors and complications of priapism in a large population of patients with sickle-cell anaemia in five centres in the UK and Nigeria, as priapism is common among these patients, but the precise characteristics of the condition in this population are poorly documented.

PATIENTS AND METHODS

A questionnaire was developed and administered to patients with sickle-cell disease. Questions were designed to define the incidence, nature, precipitants, duration, treatment and complications of priapism. A distinction was made between acute (severe) priapism and the recurrent, 'stuttering' type.

RESULTS

The questionnaire was completed by 130 patients (mean age 25 years, sd 11, range 4-66) from the five centres; 102 (78%) were homozygous Hb SS genotype, 19 (15%) were Hb SC genotype and two (1.5%) were Hb Salpha-thalassaemia. Of the patients, 46 (35%) reported a history of priapism, and of these, 33 (72%) had a history of stuttering priapism, while 24 (52%) had had an acute episode of priapism. The mean age of onset of priapism was 15 years, with 75% of patients having the first episode before their 20th birthday. Sexual activity was the most frequent precipitating factor, with fever and/or dehydration being the next most common. Of the 46 patients, 10 (21%) with a history of priapism reported having erectile dysfunction. A similar proportion reported dissatisfaction with sexual intercourse, including a fear of engaging in sexual activity.

CONCLUSION

The incidence of priapism among patients with sickle-cell anaemia is high (35%). The implications of priapism for erectile and sexual function are significant and documented in this large series. The treatment of this condition in these patients remains unstandardised. This study highlights the need for an increased awareness of the problems associated with priapism among patients, families and medical professionals.

Sickle cell disease

SCD is a major health problem requiring lifelong multidisciplinary care to manage the wide range of medical and social consequences. A number of new approaches offer the potential to have an impact on the natural history of this disease.

The effects of neonatal screening for sickle cell disorders on lifetime treatment costs and early deaths avoided: a modelling approach

BACKGROUND

The aim of the study was to calculate the cost to the UK National Health Service of providing treatment services for patients with sickle cell disorders. The rates of differential morbidity and mortality, in the first 10 years of life, between screen-detected early diagnosed and clinically presenting late diagnosed cohorts of sickle cell disorder patients are also estimated.

METHOD

A cost model was developed, based on predictions of survival and the incidence of sickle cell disorder-related events. Direct data from the NHS are lacking, so data were incorporated from disparate sources. Patients with sickle cell disorders were divided into two categories: those with sickle cell anaemia and those with sickle HbC disease.

RESULTS

Differentiating between sickle cell anaemia and sickle HbC disorder patients, the results show that the undiscounted (discounted at 6 per cent) lifetime treatment costs range from pound sterling 92323 (pound sterling 24917) to pound sterling 185614 (pound sterling 53861). The number of early deaths avoided per 100 births, as a result of early diagnosis through screening, ranges from 0.57 to 1.25.

CONCLUSIONS

The resulting estimates may act as a guide to those involved in the planning of health care provision with regard to the resources required to treat sickle cell disorder patients. Such information may also be incorporated into the evaluation of both antenatal and neonatal screening programmes for sickle cell disorders.

A home blood transfusion programme for beta-thalassaemia patients

Although home transfusion programmes are relatively common in the USA (Anon, 1990, Home Care in the 1990s. Council on Scientific Affairs. Journal of the American Medical Association, 263, 1241-1244), this type of treatment has only recently been considered in Britain and, where it is in operation, is generally supervised by trained nursing staff or via a hospice. North Middlesex Hospital now has 3 years experience of a home transfusion programme operating for beta-thalassaemia major patients, in which relatives are trained and responsible for supervision of the red-cell transfusions at home. For families who request this service, and who are willing and able to undertake it responsibly, the scheme offers the advantages of improved patient comfort, reduced absences from education or employment and reduced hospital bed usage. Patients and their carers express improved satisfaction with the treatment delivered in this way.

Red cell deformability in oral contraceptive pill users with sickle cell anaemia

The use of the combined oral contraceptive pill (COCP) in women with sickle cell anaemia (SCA) is controversial, as contraceptive steroids are thought to adversely affect erythrocyte deformability. This observational study was performed to investigate whether hormonal contraception influenced erythrocyte deformability in women with SCA. 30 women with SCA using various contraceptive modalities: COCP (n = 10); progestogen only (PO) contraception (n = 10) and non-hormonal contraception (n = 10) were recruited. Erythrocyte deformability was assessed using the clogging rate (CR) and red cell transit time (RCTT). There was no statistical difference in the mean CR and RCTT between the three groups of women (one-way ANOVA). Current contraceptive steroids do not appear to impair red cell deformability in women with SCA.

High prevalence of low bone mass in thalassaemia major

Cooley's original description of beta-thalassaemia major included marked bone deformities as a characteristic feature. These were thought to be due to expansion of haemopoiesis attempting to compensate for the congenital anaemia. Regular blood transfusions from infancy prevents these skeletal problems. Nevertheless, symptoms due to bone disease frequently occur in adult patients. Osteoporosis has not previously been reported as a cause of severe morbidity in thalassaemia major. The present study shows a high prevalence of low bone mass among thalassaemia major patients and analyses the predisposing causes. Bone density scans were performed in 82 patients with transfusion-dependent beta thalassaemia. Factors known to be associated with low bone mass such as gender, endocrine disorders and lifestyle activities, together with factors specific to the thalassaemia and its management, were included in a series of univariate analyses to ascertain any significant associations. 42 (51%) of the patients had severely low bone mass and a further 37 (45%) had low bone mass. The three factors showing a statistically significant association with severely low bone mass were male sex, 24/38 (63%) males had severely low bone mass, compared with 18/44 (41%) females, the lack of spontaneous puberty, 22/32 (69%) who required therapeutic induction of pubertal development had severely low bone mass, compared with 19/47 (40%) with spontaneous puberty and diabetes, 8/10 (80%) diabetic patients had severely low bone mass, compared with 23/56 (41%) with normal glucose tolerance. There was no association between the bone mineral density measurements and the haematological characteristics or treatment details of these patients. Severely low and low bone mass are common findings in patients with beta-thalassaemia major despite optimal transfusion and iron chelation. The associated features suggest that the severely low bone mass is due to endocrine abnormalities, in contrast to the haematological causes of bone disease characteristically seen in untreated thalassaemics.

The effect of ovarian steroids on sickle cell deformability

Sickle cell disease (SCD) is an incurable debilitating disease affecting the Afro-Caribbean population. The combined oral contraceptive pill (COCP), an effective and popular method of contraception, is often denied to women with SCD for fear that the disease process may have a synergistic effect on the coagulation changes associated with contraceptive steroids. In this study red cell deformability was assessed in 10 women with SCD and 10 comparable women with normal AA haemoglobin. Neither group was on exogenous hormones. The red cells were taken in the follicular phase of the menstrual cycle when women have low endogenous levels of oestradiol and progesterone. The effect of the steroids contained in the COCP on red blood cells was simulated by incubation with therapeutic concentrations of oestradiol and progesterone. Red cell deformability is a measure of the ease with which erythrocytes flow through small capillaries and was assessed using the parameters red cell transit time (RCTT) and clogging rate (CR). Therapeutic concentrations of oestradiol and progesterone did not appear to influence red cell deformability in women with SCD or normal AA haemoglobin.

Pregnancy management and outcomes in women with thalassaemia major

The health background, management and outcomes of 25 pregnancies in 18 women with transfusion dependent beta thalassaemia are described with particular consideration of appropriate preconceptual guidance for such women. This is an observation study of women attending three collaborating London hospitals. Nine of the pregnancies required induction of ovulation. Two pregnancies were complicated by diabetes and three by hepatitis C. One patient was hepatitis B positive. Two pregnancies were in women with cardiac problems, one of whom died of cardiac failure nine months after delivery of a live child. Two of the pregnancies miscarried and three were terminated, with the others resulting in 21 live children (including one set of twins). 14 of the pregnancies were delivered by caesarean section. After pregnancy five women developed secondary amenorrhoea, two developed cardiac problems and two developed diabetes.

Combination therapy with interferon alpha and ribavirin for chronic hepatitis C virus infection in thalassaemic patients

Hepatitis C virus (HCV) infection is common in multi-transfused thalassaemic patients, and, in combination with transfusional iron overload, can result in progressive liver disease. Therapy with interferon-alpha causes a sustained loss of HCV in only 15-25% of patients, and there is as yet no established effective therapy for those who fail to respond. We have conducted a pilot study of combination anti-viral therapy for patients who failed to respond, or relapsed after an initial response to single-agent interferon-alpha. Patients were treated for 6 months with interferon-alpha 2b, given subcutaneously three mega units thrice weekly, together with ribavirin, orally 1 g daily. 11 patients were enrolled, their median age was 24.9 years. 8/10 evaluable patients had cirrhosis on biopsy, five were infected with HCV type 1 and all but one had initial HCV RNA titres > 10(6) genomes/ml. Five patients (45.5%) had a sustained virological response with loss of serum HCV RNA for > 6 months after finishing therapy. There was no clear association between response to therapy and age, histology, HCV genotype, or HCV RNA titre. Transfusion requirements were significantly increased during the treatment phase, probably due to ribavirin-induced haemolysis, and this necessitated intensification of iron chelation therapy. Serum ferritin levels decreased significantly in those who responded. These results suggest that combination therapy is potent in clearing HCV infection, and may provide effective second-line therapy for thalassaemic patients who have failed to respond to interferon-alpha monotherapy.

Incidence of endocrine complications and clinical disease severity related to genotype analysis and iron overload in patients with beta-thalassaemia

The incidence of endocrine dysfunction in relation to the detailed genotype of beta-thalassaemia is investigated in this study. In addition, the association of genotype to specific clinical features of beta-thalassaemia is examined, together with the relationship between serum ferritin levels and endocrine complications. Ninety-seven patients were included, all with transfusion dependent beta-thalassaemia. Patients were divided into 2 categories; group 1 consisted of patients with a beta0/beta0 genotype with or without a concomitant alpha-globin gene deletion as well as patients with beta0/beta+ or beta+/beta+ genotype and normal alpha-globin chain synthesis. Group 2 included patients with beta+/beta+ or beta+/beta0 genotype and one alpha-globin chain deletion and those with a moderate amount of beta-globin chain synthesis (beta++) and normal alpha-globin chain synthesis. The results showed that group 1 patients were more likely to have severe clinical disease (p=0.005). Sixty-four patients (66%) had at least 1 endocrine disorder and 39 (40%) had multiple endocrinopathies; the most common abnormality was hypogonadotrophic hypogonadism (HH). There was a significant association between patients with group 1 genotypes and the presence of HH and impaired glucose tolerance or diabetes. A positive correlation was demonstrated between serum ferritin concentrations and the presence of thyroid or parathyroid dysfunction.

Moderate reduction of beta-globin gene transcript by a novel mutation in the 5' untranslated region: a study of its interaction with other genotypes in two families

We have identified two individuals of Greek Cypriot origin with thalassemia intermedia. Molecular analysis has shown that each individual is a compound heterozygote for a previously described beta zero thalassemia allele and a novel mutation, C-->G in position +33, in the 5' untranslated region of the beta globin gene. In both families the beta +33 allele is associated with the same beta haplotype (-++- ) suggesting that it is likely to be of a single origin, beta-cDNAs from normal and mutant beta alleles were isolated from peripheral blood reticulocytes using the technique of reverse transcription-polymerase chain reaction. Because the beta +33 (C-->G) mutation creates a cutting site for the restriction enzyme NlalV, we could demonstrate by differential restriction analysis that the beta gene with +33 mutation showed 25% to 35% residual activity compared with normal. The additive effect of this moderate deficit in beta globin production with the beta zero thalassemia mutation would explain the clinical phenotypes observed in the two probands. In contrast, two siblings of one proband who were also compound heterozygotes for the same beta thalassemia mutations, as well as heterozygotes for a nondeletional alpha thalassemia variant, and two other compound heterozygotes for the beta +33 and a beta+ thalassemia allele were completely asymptomatic. Individuals heterozygous for the beta +33 C-G mutation alone are clinically and hematologically silent, with normal red blood cell indices and normal levels of hemoglobin (Hb) A2. A direct relationship between genotypic and phenotypic severity is clearly demonstrated in these cases with obvious implications for prenatal diagnosis.

Psychosocial and clinical burden of thalassaemia intermedia and its implications for prenatal diagnosis

Twenty eight patients with thalassaemia intermedia and their parents were interviewed using specifically designed questionnaires to evaluate psychosocial burden. Hospital notes were analysed for clinical burden. A wide variation was found for both patients and parents, ranging from virtually unaffected to severely affected. Normal sexual function and setting up a family were mentioned by patients and parents as being particularly important for quality of life. Over half (58%) of the patients had problems with sexual maturation and functioning, and continuous monitoring of all patients with thalassaemia intermedia by a paediatric endocrinologist is therefore strongly indicated. Most parents said, in light of their experiences, that they would opt for prenatal diagnosis and termination of affected pregnancies even if a genotype predicting the mild form of disorder were discovered.

Successful bone marrow transplant for Fanconi anaemia in transformation

We present a patient who was diagnosed as suffering from Fanconi anaemia at the age of 36 years. At the time of diagnosis his bone marrow showed features of pre-leukaemic transformation. He received an allogeneic bone marrow transplant (BMT) from his HLA-identical sibling. The post-transplant course was unremarkable with evidence of trilineage engraftment at day +32 and no acute or chronic GVHD. He is well with sustained engraftment and no haematological evidence of Fanconi anaemia 18 months post-transplant.

Low incidence of non-A, non-B post-transfusion hepatitis in London confirmed by hepatitis C virus serology

To see whether the introduction of screening tests for post-transfusion non-A, non-B hepatitis (NANBH) in the UK would be worth while, the incidence of such hepatitis was assessed among patients receiving blood during operations at five hospitals served by the North London Blood Transfusion Centre. 387 patients, who each received blood or blood components from an average of 3 donors were followed up prospectively and blood samples were taken every 2 weeks for 3 months and then each month for a further 3 months. 229 patients also provided a sample at 12 months. All available patient and donor samples were tested for alanine aminotransferase concentrations and for antibody to hepatitis C virus (anti-HCV) by ELISA. Repeatedly anti-HCV positive samples were submitted to supplementary HCV assays. 1 of the 387 patients showed biochemical evidence of acute post-transfusion NANBH after exclusion of non-viral causes. Anti-HCV developed in this patient and the seroconversion was confirmed by recombinant immunoblot assay and polymerase chain reaction. Serum from 1 of the 8 donors whose blood he received was positive for anti-HCV by all three methods. In another patient HCV seroconversion was shown by ELISA but alanine aminotransferase concentrations remained normal throughout follow-up. His samples and those of his 2 donors were negative for HCV by the polymerase chain reaction. A third patient showed rises in alanine aminotransferase compatible with post-transfusion NANBH, but serology and polymerase chain reaction assays for HCV were negative for her samples and those of her donors. Anti-HCV reactivity likely to be false positive (negative by both confirmatory tests and no adverse effects in recipients) was seen in 6 of 1283 donors. This study, despite its being carried out in the part of the UK with the highest frequency of infectious markers in blood donations, has shown a very low incidence of post-transfusion NANBH.

An evaluation of the Coulter VCS differential counter

An evaluation of the Coulter VCS (volume, conductivity, light scatter) automated differential counter demonstrated satisfactory correlations with manual 800-cell differential counts for neutrophils, lymphocytes, monocytes and eosinophils. For the detection of abnormal cells, 12.2% of samples gave false-negative results on the VCS, and 13.4% gave false-positive results. However, only 0.8% of the false-negatives would be expected to be picked up by a standard 100-cell manual differential count. Carry-over accorded to manufacturer's specifications and throughput was 60 samples/h. Reference normal ranges have been established and the instrument's precision and performance with leucopenic and neonatal blood samples assessed.

Detection of important abnormalities of the differential count using the Coulter STKR blood counter

An assessment of the three part differential provided by the Coulter STKR blood counter showed good correlation when compared with an 800 cell manual differential. Satisfactory flagging of eosinophilia, basophilia, and the presence of immature cells was found. The use of variables derived from the STKR in conjunction with interpretive reporting and user-defined flagging enabled this department to reduce considerably the numbers of films requiring manual differential counts.

Clinical management of severe sickle cell disease

Patients affected by sickle cell disease encounter varied and often severe clinical problems directly related to their condition and are at greater risk than the general population from particular infections, thrombosis and certain surgical pathologies. The current clinical management policies for the severe acute problems arising in these patients, and measures undertaken to prevent these where possible, are discussed.

Shoshin beriberi: an underdiagnosed condition?

Shoshin beriberi, a fulminant form of heart failure due to thiamine deficiency has a different presentation to the classical form of beriberi heart failure. It is characterized by a cold periphery, low blood pressure, renal shutdown and a severe metabolic acidosis. The true incidence is unknown. Two patients were seen within a few months in a general hospital and in both dietary deficiency of thiamine was a major factor.

Exchange transfusion and quinine concentrations in falciparum malaria

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