Study of Dry Beriberi in Mayotte, Comoro Archipelago

Determination Study of Dry Beriberi in Patients Native to the Comoro Archipelago, in Mayotte (MABECO).

The purpose of this study is to assess the existence of a genetic factor, suspected to be involved, aside from likely food deficiency contribution, in occurrence of dry beriberi, in patients who experienced dry beriberi and in a case group composed of 3 people, free from beriberi, within the same household.

A team of 2 investigators, a nurse and an investigator speaking French, Shibushi and Shimaore (3 languages in use in Mayotte), will visit exposed patients who agreed to participate to the study.

3 controls, fulfilling inclusion criteria, will be recruited within the household by drawing lots.

Clinical examination and food survey by means of a questionnaire will be performed.

Blood samples will be drawn to determine thiamine status, vitamin B1 dosage, erythrocyte transketolase activity and thiamine pyrophosphate effect, analysis will be performed by Biomnis laboratory in Lyon.

For the genetic study, 4 drops of blood will be put down on Whatman paper and sent to Dr Johannes COY in Darmstadt Germany, for DNA extraction and PCR screening for mutations.

Inclusion Criteria:

• patients
• Native to the Comoro Archipelago (Grande Comore, Mayotte, Anjouan, Mohéli)
• Fulfilling the clinical definition of the dry beriberi.
• Both sexes.
• Older than 15 years and 3 months (limit of the paediatrics).
• Having signed and whose legal representatives signed the form of assent, having understood the information.
• Benefiting from a social coverage regime.
• Controls
• Native to the Comoro Archipelago.
• People living in the same household as the patient, sharing the same meals.
• Both sexes.
• Older than 15 years old and 3 months.
• Free from beriberi.
• With normal neurological examination.
• Having signed and whose legal representatives signed the form of assent, having understood the information.
• Benefiting from a social coverage regime.

Exclusion Criteria:

• Aged under 15-year-old and 3 months.
• For the patients and the witnesses, the presence of pathologies known to increase needs in vitamin B1 (cancer, infectious diseases, fever, hyperthyroïdism, chronic alcoholism).