LB7
The impact of consanguinity on cancer in a high endogamous population
Abdulbari Bener, Hanadi R El Ayoubi, Lotfi Chouchane, Awab I Ali, Aisha Al-Kubaisi, Haya Al-Sulaiti, Ahmad S Teebi
Weill Cornell Medical College and Hamad Medical Corporation, Doha, Qatar
Background
Many epidemiological studies have reported that inbreeding has little or no
effect on incidence of cancer. Due to the high prevalence of
consanguinity In Qatar (54%), the effect of consanguinity on cancer is of
special importance for the people in Qatar.
Aim
The aim of this study was to examine whether parental consanguinity affect
the risk of cancer in a local Arab highly inbred population.
Method
A matched case-control study, which was carried out in Al-Amal cancer
hospital and Primary Health Care Centers in Qatar over a period from August
2008 to February 2009.
The study included 370 Qataris and other Arab expatriates with various types of cancers and 635 control matched by age and ethnicity. A questionnaire that included the socio-demographic information, type of consanguinity, medical history, and tumour grade was designed to collect the information of cases and controls.
Results
The study revealed that the rate of parental consanguinity was similar in
both cases (29.5%) and controls (29.9%) with a higher inbreeding coefficient in
controls (0.0170.03) compared to cancer patients (0.01550.03). Other
Arab expatriates had higher incidence of cancer (61.1%) than in Qataris
(38.9%). The inbreeding coefficient was higher in male cancer patients
(0.01890.03), whereas lower in female cancer patients (0.0140.03) compared to
controls. Controls were more inbred in overall studied subjects
(23.6%) and women (23.8%) than cases. The coefficient of inbreeding was
lower in patients with breast (0.014), skin (0.012), thyroid (0.008) and female
genital (0.014) cancers, whereas it was higher in cases for leukemia and
lymphoma (0.018), colorectal (0.025) and prostate (0.017) with no significant
difference between cases and controls. No significant difference was observed
between cases and controls in the parental consanguinity, mean coefficient of
inbreeding and proportion of more inbred subjects.
Conclusion
The study findings revealed that although the consanguinity rate is high in
the Arab population, it has no effect on the incidence of cancers overall.
Reduction of cancer risk is greater in women than men. Although the
inbreeding has no effect on cancer overall, there was an increased risk found
in leukemia and lymphoma, colorectal and prostate cancer groups, but reduced
risk in breast, skin, thyroid and female genital cancer groups.
