الفهرس 
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Abstract
Children with Down syndrome may be at increased risk of becoming overweight or obese due to physiological factors, including hypothyroidism, decreased basal metabolic rate and poor mastication or behavioral factors such as dietary patterns and low levels of physical activity.
Polymorphisms of the glucocorticoid receptor may influence the sensitivity to glucocorticoids by altering GR expression. Bcl1 is a common polymorphism of the GR gene with two allelic variant that may be related to many metabolic disorders including obesity.
The purpose of this study was to investigate the relationship between Bcl1 polymorphism and obesity in Down Syndrome children as well as non-DS obese children.
We conducted this study on 300 children, they classified into 4 groups as follow:
group 1 (Down-obese): 80 children with Down syndrome with obesity according to increased body mass index, (BMI ≥ 95th percentile for age and sex on DS BMI growth chart).
group 2 (Down-non obese):70 children with Down syndrome with normal body mass index, (BMI=5-85th percentile for age and sex on DS BMI growth charts).
group 3 (Normal-obese): 80 (non-DS) children with obesity according to increase body mass index, (BMI ≥ 95th percentile for age and sex on BMI regular growth chart).
group 4 (Normal-non obese): 70 (non-DS) children with normal body mass index, (BMI=5-85th percentile for age on BMI regular growth chart.
Summary
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All children were subjected to the following after informed consent:
1. Detailed history taking.
2. Family history and pedigree.
3. Full clinical examination.
4. Anthropometric measurements: including head circumference, weight, height and body mass index and all data was plotted on growth charts for Down and normal children.
5. Laboratory investigation: Complete blood count, TSH and freeT4 as indicated.
6. Genetic study: Genotyping of Bcl1 gene polymorphism in all studied children by Real Time PCR technique at Central Laboratory of Faculty of Medicine, Menoufia university hospital.
The Results of this study demonstrated:
Genotype and allelic distribution showed a significant increase in frequency of mutant homozygous CC genotype among down- obese group compared to other groups.
However heterozygous GC genotype was significantly higher among non-obese groups compared to obese groups.
The presence of CC genotype is associated with significantly higher BMI mean values compared to other genotypes in both male and female children.
Comparing Bcl1 gene frequency between down and non-down groups there is high significant increase in frequency of mutant homozygous CC genotype and heterozygous GC genotype among down children compared to non-down children.
Summary
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A significant increase in birth weight in obese children compared to non-obese children.
Higher frequency of endocrinal disturbances include hypothyroidism and diabetes mellitus among Down groups compared to normal groups.
We can conclude that:
High birth weight infant more susceptible to become obese child.
Bcl1 variant of NR3C1 gene may be not associated with obesity susceptibility in Egyptian children, although significant increase of CC genotype in Down obese which need further studies with larger sample size to confirm this conclusion.
The result also revealed a higher tendency of mutant C allele and C allele containing genotypes (CC & GC) to occur more frequently in Down children, which may be relevant with pathophysiology of DS.
Finally, we recommend that: Further large studies needed to verify the probable relation between Bcl1 polymorphism and obesity in Down syndrome individuals. More genes needed to be studied with involvement of lipid and hormonal studies to clarify more risks and causes of obesity, hence, help in prevention of obesity.
Timely monitoring and early recognition of medical problems that can affect weight in Down syndrome children with appropriate early intervention to decrease the overall morbidity and result in better outcomes.