الفهرس 
DOWN SYNDROMEOnly 14 pages are availabe for public view
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Abstract
I
nterestingly, neonates with DS are at a high risk of developing a hematologic disorder referred to as transient abnormal myelopoiesis (TAM).
In about 60% of cases, TAM resolves spontaneously within the first 3 months of life. An estimated 20% to 30% of babies with TAM subsequently develop ML-DS (Myeloid Leukemia in DS). Thus, TAM is an important clinical problem.
Acquired mutations in exon 2 of the hematopoietic transcription factor GATA-1 mapped at Xp11.23 are consistently present in the affected cells of children with TAM and ML-DS.
The study included consequent 79 neonates with Down syndrome based on clinical examination and confirmed by karyotype from the outpatient Genetics Clinic, Children’s Hospital-Ain Shams University. Patients age from 1 day to 90 days.
Demographic data were recorded including name, age, sex, order of birth, consanguinity. Full history was taken with stress on symptoms of TAM as history of bleeding, jaundice, bruises and pallor. Thorough clinical examination with special stress on anthropometric measurements {weight (kg)-height (cm)} were recorded, features of pancytopenia: pallor, purpura, ecchymosis, bleeding per orifices and recurrent infections, full abdominal examination with stress on each abdominal organ size, surface, border, and consistency.
Complete blood count (CBC) was done using Beckman Coulter-Gen. system 2, USA and manual white blood cell differential count including blast cells count after staining with Leishman stain and values were compared to age related reference ranges.
DS patients were divided into three groups according to blast cells count:
group A (4 patients): DS neonates with blasts >10%
group B (11 patients): DS neonates with blasts 1-10%
group C (64 patients): DS neonates with 0% blasts
Fifteen patients only were subjected to sequencing of exon2 of GATA1 gene including all patients of group A and eleven randomly selected cases from the two other groups B and C.
Those 15 patients were divided into two groups according to results of GATA1 mutation analysis results:
Mutation positive group: 4 patients
Mutation negative group: 11 patients
We found that 19 % of DS neonates (15 of 78) had blasts on blood smears (range 1%-60%). Of these 15 patients subjected to sequencing of exon 2 of GATA1 gene, only 4cases (26%) had GATA1 mutations all 4 had blasts >10%. We found highly significant difference present regarding splenomegaly between DS neonates with GATA1 mutations (25% of cases) and DS neonates without GATA1 mutations (0% of cases) (p=0.035).
We also found a significant higher total leukocytes count in DS neonates with blasts >10% compared to patients with blasts <10% (p value =0.028). A significant lower MCV was found in DS neonates with TAM compared to DS neonates without TAM (p value=0.003).