Several congenital disorders may cause neutropenia. The recent advances in the field of molecular biology have facilitated our knowledge concerning pathophysiological mechanisms leading to these disorders. The molecular basis of disorders with defective myelopoiesis (severe congenital neutropenia and cyclic neutropenia) and disorders due to defective RNA processing (Shwachman Diamond syndrome and cartilage hair hypoplasia) are the two congenital neutropenia syndromes that are addressed in this review. Molecular defects defined by means of these disorders are very important for our understanding of the cause of the disorders as well as some unknown molecular mechanisms.

The aim of this review was to compile published data on factor V 1691 G-A alteration in a healthy Turkish population and also to stimulate the reporting of unpublished data, in order to create a map for factor V Leiden (FVL) in Turkey. From a total of 4276 healthy individuals from 26 different centers of Turkey, 345 FVL carriers (7.9%) were determined. FVL was strikingly high among newborns from two different centers (10.9%).

OBJECTIVE: Varicella is a common childhood infection and has a number of complications in the unvaccinated population. Perforin, found in natural killer cells, is important for the killing of virally infected cells. For this reason, the aim of this study was to determine natural killer cell count and activity, perforin expression, and Fas and soluble Fas ligand (sFas-L) levels in immunocompetent children with varicella infection and define any possible relations between the levels and varicella complications.
METHODS: Forty children were analyzed at diagnosis and on the 15th day of varicella infection. There was a significant difference in hemoglobin levels and leukocyte and platelet counts between days 0 and 15.
RESULTS: Thirteen (32%) patients were found to be lymphopenic. Natural killer cell count and activity were significantly higher on day 15 when compared to values at diagnosis. The Fas-mediated apoptotic pathway was found to be active in acute varicella infection because Fas and sFas-L levels at diagnosis were higher than values on day 15.
CONCLUSION: These findings suggest that the Fas and Fas-L apoptotic pathway is active during the acute phase of the viral infection and that it becomes inactive by day 15, paralleling the hematologic recovery.

Objective: The aim of this study was to determine the laboratory diagnosis and genetic origins of the hemoglobin (Hb) variants, Hb D-Los Angeles and Hb Beograd observed frequently in our region.
Material and Methods: Hb variants were investigated in one Hb D-Los Angeles and two Hb Beograd families. These families were unrelated with each other. For the determination of Hb variants, alkaline/acid electrophoresis, HPLC, DE-52 micro-column chromatography procedures were applied. Mutations were determined by non-radioactive fluorescence automated DNA sequencing. Beta globin gene cluster haplotypes were identified by RFLP analysis at seven loci known as ε-Hinc II, Gγ-Hind III, AΨβ-Hind III, 5’Ψβ-Hinc II, 3’Ψβ-Hinc II, β-Ava II ve 3’β-Hinf I.
Results: Three novel beta globin gene cluster haplotypes were identified as in relation with Hb D-Los Angeles [--+-+++], Hb Beograd [+----++ and -+-(+/-)(+/-)+(+/-)]. These haplotypes were reported for the first time in the world population
Conclusion: In this study we emphasize the importance of DNA seqeuncing and other laboratory procedures for the identification of Hb variants in premarital diagnosis. On the other hand we discuss also the genetic origins of these Hb variants.

Objective: The estimation of platelet count from blood smears is a daily routine laboratory test, which should be systematic each time the automated count is erroneous.
In our laboratory, we estimate the platelet count indirectly by using the automated red blood cell (RBC) and calculating the platelet count on the basis of the red cell: platelet ratio in a stained blood film. In this study, we attempted to verify the reliability of this technique. Material and Methods: One hundred ninety-one platelet counts were executed by two laboratory methods: an automated count using an impedance cell counter and then a manual method by reviewing microscopic blood smears. The number of platelets per 1000 erythrocytes was multiplied by the automated RBC (x106 cells/µl) to give an approximate manual count (x103 cells/µl). Two paired t-test was used for comparison of the two methods. Results: The regression analyses for the entire data set collected in our study with the two laboratory methods gave the following least squares equation by comparing the automated (y) to the manual method (x): y=0.8548x + 12.013
(r=0.908). The paired t-test showed no significant difference between the two methods (p>0.05) and the Intra-class Correlation Coefficient (ICC) was equal to 0.905.
The plot of the differences between the automated and manual values against their means according to Band and Altman design showed that the difference mean was 3.209 with a standard deviation SD=46.331. We noticed that 93% of the differences were within the agreement limits (mean±2SD), and that 77% of the differences were less than 20,000 platelets/µl. Conclusion: Estimating platelet count on the basis of the red cell: platelet ratio is a reliable technique and it should be proposed as a method of reference.

OBJECTIVE: In southeast Yemen, visceral leishmaniasis (VL) is endemic in Lahj and Abyan and also in Hagga and Sadah, the areas lacking adequate diagnostic facilities. This study describes the clinical and hematological features in 64 cases of childhood VL.
METHODS: All children below 12 years of age who were managed as inpatient cases from 1 January to 31 December 2005 were included in this study. The diagnosis of VL was established by demonstration of leishmania parasites in bone marrow aspiration. Demographic information, physical signs at presentation and results of complete blood count were recorded and bone marrow aspirations were done for LD bodies.
RESULTS: Mean age of the patients was 30 months, and there were 33 females and 31 males. Fever was seen in 100% of children with duration before diagnosis of 56 days. Splenomegaly was present in all cases and hepatomegaly in 84.4%, with mean enlargement of spleen and liver of 9.3 and 3.5 cm, respectively. Mean hemoglobin level, white blood cell and platelet counts were 6.6 g/dl, 3.58x109 /L and 71.7x109 /L, respectively. Absolute neutrophil count was <0.78x109 /L and mean reticulocyte count was 1.7%.
CONCLUSION: Fever, hepatosplenomegaly and pancytopenia were the most common clinical and hematological manifestations in Yemeni children with VL.

OBJECTIVE: Nanoparticles differ from the same material at larger scale in chemical and physical properties. The effect of nanoparticle on the blood cell still needs scientific verification.
METHODS: The direct effect of gold nanoparticles on lymphocyte was direct assessed by in vitro assay.
RESULTS: In this work, the author reported additional results from specific observation on lymphocyte exposure to gold nanoparticle.
CONCLUSION: This result confirms for direct intracellular penetration effect.

The combination of Marfan syndrome with lymphoma is extremely rare. This report describes a case of Marfan syndrome who presented with chest discomfort and was diagnosed to have an aortic aneurysm and an additional incidental mediastinal mass that on further investigation turned out to be a diffuse large B cell lymphoma. We have suggested a hypothesis which can explain the occurrence of lymphoma in Marfan syndrome.

Although rare, avascular necrosis of bone is a serious and incapacitating complication seen in children with acute lymphoblastic leukemia receiving high dose steroids. Here we present a 16 year-old girl who developed bilateral knee and right ankle avascular osteonecrosis one year after intensive chemotherapy for medium risk acute lymphoblastic leukemia. Indirect curettage of necrotic tissue and bone grafting were performed for both knees whereas conservative measures had been sufficient for the ankle. Early recognition of this condition is important in prevention of disabling sequela in skeletal system.