The prevalence of asthma among  Israeli Arab children from the triangle region:  Environmental and genetic susceptibility aspects.

 

Background:

The exposure to environmental risk factors might be an indication to an increase in asthma prevalence in the worldwide, over the past 50 years (1). However some individuals develop asthma symptoms, suggesting that individual genotypes determine sensitivity to environmental pollution exposure. During the previous decade, molecular epidemiological studies have provided new perspectives on studying environmental risks in pediatric populations, based on the growing understanding that children may be more susceptible to toxicants than adults (2-4). Recently, many studies have been undertaken in order to investigate the prevalence of asthma among various societies (5-6). Furthermore, many research works were carried out in order to determine the genetic susceptibility to asthma disorder (7-8).

The phenomenon of consanguineous marriages has been common in different societies worldwide since many decades (9-11). For hundreds of years consanguineous marriages were part of the Arabian culture. The prevalence of consanguineous marriages in the Arab world is considered to be much higher (35% - 55%) compared to that (~1%) in Western countries (12). Israeli Arab community is considered to have a high rate of consanguinity reaching to about 42% (13). Recently, a detailed study on the frequency and patterns of consanguineous marriages in four Israeli Arab villages in the northern triangle region over two separate periods of times was conducted. It revealed that there has been a change in the pattern of consanguinity in these selected villages (14). As it is a well known fact that consanguineous marriages increase significantly the genetic disorders, which resulting of increase the susceptibility to numerous infectious and chronic diseases including asthma.  Asthma may be occurring in high prevalence in the Israeli Arab community as it has a high rate of consanguinity (15). Despite the high prevalence of the asthma among children, there is a lack of studies performed on Arab population of Israel in terms of determining its prevalence and the genetic susceptibility to the disease.

Exposure to environmental pollution may be attributed to linkages with specific polymorphisms or with chromosomal regions that may be revealed (5-8). Inhaled environmental agents induce several biological responses in asthmatics; including the induction of adaptive and innate immunity that lead to acute and chronic forms of airway inflammation and airway remodeling. The airways morbidity may be evaluated by health questionnaire as well as spirometry in large epidemiological studies (16-19).

Nitric oxide (NO), which is produced in the exhalant from the respiratory tract where it plays important regulatory functions, can be detected (20). Serial measurement of exhaled nitric oxide (eNO) has been shown to be a good noninvasive marker of asthma control. In this proposed research work, we'll investigate whether the level of exhaled nitric oxide (eNO) provides a more sensitive measurement to assess adverse pulmonary effects of air pollution than conventional lung function indices. Furthermore, we'll study the impact of environmental pollutant exposure on eNO levels in asthmatic and non-asthmatic children.

 

 Objectives:

1. To determine the prevalence of asthma among children in selected Arab villages of the triangle region in Israel.

2. To assess the genetic inheritance manner of susceptibility to asthma among those children.

3. To identify risk factors (genetic related and environmental) for detrimental health outcomes.

4. To facilitate multilateral cooperation between environmental and public health stakeholders.

5. To use the knowledge on the genetic markers associated with the asthma susceptibility in genetic consultation practice for reducing the prevalence of the disease in the Arab populations in the region.