Methods: A total of 282 (137 VLBW and 145 NBW) infant-caregivers were approached during the time of their scheduled follow-up visit (8, 18, or 36 months corrected/chronological age) for genetic specimen collection. The caregivers were predominantly (94%) biological mothers. The Oragene® DNA (DNA Genotek, Inc. Ottawa, Canada) saliva kit was utilized for specimen collection. Caregiver and infant, unstimulated saliva specimens were collected using the manufacturer’s collection vial or sponges respectively. DNA was extracted from saliva samples according to the Oragene extraction protocol and DNA concentration levels were recorded for the subjects. Statistical analysis compared the mean DNA concentration levels between VLBW and NBW groups.
Results: A total of 264 infants/caregivers (VLBW: 126, NBW: 138) agreed to participate in genetic collection and 18 refused (11 VLBW and 7 NBW). In addition, 47 fathers also provided specimens for genetic collection. The mean concentration levels of DNA were statistically similar (p> 0.05) between VLBW (67.2±52.8) and NBW (64.8±56.4) infants. Also, statistically similar levels were found between VLBW (147.8±150.3) and NBW (135.16±132.2) caregivers.
Conclusions: The overall 94% participation rate indicates that subjects enrolled in a longitudinal study are very willing to participate in additional genetic specimen collection. The DNA concentration levels extracted from VLBW and NBW groups were similar, of high quality, and have sufficient quantities to conduct future candidate gene analysis for caries susceptibility. Supported by NIDCR R01 DE 017947-01 and CTSC UL1RR024989
Keywords: Epidemiology, Genetics, Infants, Longitudinal and Saliva