Clinical trial NCT00339521: Genetic Susceptibility to Childhood Respiratory IIlness in Mexico City
Official title: Genetic Susceptibility to Childhood Respiratory Illness in Mexico City
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Asthma
Keywords: Asthma
Mexico
Triads
Polymorphism
Genetic Predisposition
Lead sponsor: National Institutes of Health Clinical Center (CC)
Sponsor class: NIH
First posted: 2006-06-21
Enrollment: 2362
Sex: ALL
Minimum age (years): 4
Maximum age (years): 17
Standard ages: CHILD
Accepts healthy volunteers: no
Observational model: FAMILY_BASED
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Asthmatic children registered at the allergy clinic of the Pediatric Hospital Frederico Gomez in Mexico City and their biological parents.

Brief summary: We propose to add a collection of genetic material to a clinical trial of anti-oxidant supplementation for the amelioration of asthma in 7-12 year olds being conducted at a public pediatric hospital in Mexico City. The anti-oxidant study has been approved by the Institutional Review Board of the National Institute of Public Health in Mexico City and is scheduled to begin in September 1998. The purpose of this add-on study is to examine genetic polymorphisms that may be related to asthma. Asthma cases will be compared with their parents as controls. In partaicular, we will save the buffy coat from the blood collection being done on the asthmatic child for measurements of plasma micronutrients in the anti-oxidant trial for extraction of DNA. This part of the sample would otherwise be discarded. In addition, we will enroll the parents of the asthmatic child as controls for the child. From the parents, either a 10 ml blood sample or if they prefer, a sample of buccal cells will be collected. Although our current plan is to compare the asthmatic child to the parents using statistical methods based on the "transmission disequilibrium test" because research into various family designs for candidate gene studies is rapidly evolving and various sibling control sample strategies have been discussed, we would also like to collect a genetic sample on as many of the child's siblings as possible with priority given to those closest in age. This will enhance the future usefulness of the samples. We anticipate enrolling approximately 200 families....

Detailed description: We propose to add a collection of genetic material to a clinical trial of anti-oxidant supplementation for the amelioration of asthma in 7-12 year olds being conducted at a public pediatric hospital in Mexico City. The anti-oxidant study has been approved by the Institutional Review Board of the National Institute of Public Health in Mexico City and is scheduled to begin in September 1998. The purpose of this add-on study is to examine genetic polymorphisms that may be related to asthma. Asthma cases will be compared with their parents as controls. In particular, we will save the buffy coat from the blood collection being done on the asthmatic child for measurements of plasma micronutrients in the anti-oxidant trial for extraction of DNA. This part of the sample would otherwise be discarded. In addition, we will enroll the parents of the asthmatic child as controls for the child. From the parents, either a 10 ml blood sample or if they prefer, a sample of buccal cells will be collected. Although our current plan is to compare the asthmatic child to the parents using statistical methods based on the "transmission disequilibrium test" because research into various family designs for candidate gene studies is rapidly evolving and various sibling control sample strategies have been discussed, we would also like to collect a genetic sample on as many of the child's siblings as possible with priority given to those closest in age. This will enhance the future usefulness of the samples. We anticipate enrolling approximately 200 families.

Eligibility criteria: * INCLUSION CRITERIA:

Moderate to severe asthma, ages 7-12 and residing within 5 km of a particular ambient air pollution monitoring station.

Primary outcomes:
measure: To create a resource to examine genetic susceptibility to asthma in Mexico City.
timeFrame: End of Study
Secondary outcomes:
Other outcomes:
Locations:
city: Mexico City
country: Mexico
facility: Hospital Infantil de Mexico Federico Gomez
Study officials:
affiliation: National Institute of Environmental Health Sciences (NIEHS)
name: Stephanie London, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Sandford A, Weir T, Pare P. The genetics of asthma. Am J Respir Crit Care Med. 1996 Jun;153(6 Pt 1):1749-65. doi: 10.1164/ajrccm.153.6.8665031.
citation: Hopes E, McDougall C, Christie G, Dewar J, Wheatley A, Hall IP, Helms PJ. Association of glutamine 27 polymorphism of beta 2 adrenoceptor with reported childhood asthma: population based study. BMJ. 1998 Feb 28;316(7132):664. doi: 10.1136/bmj.316.7132.664. No abstract available.
citation: Slutsky AS, Zamel N. Genetics of asthma: the University of Toronto Program. University of Toronto Genetics of Asthma Research Group. Am J Respir Crit Care Med. 1997 Oct;156(4 Pt 2):S130-2. doi: 10.1164/ajrccm.156.4.12tac-10.