C7 complement deficiency in an Israeli Arab village

Area of Science:

• Immunology
• Genetics

Background:

• Deficiencies in terminal complement components heighten susceptibility to Neisserial infections.
• The prevalence and genetic basis of complement deficiencies vary across different populations.

Purpose of the Study:

• To report the first instance of complement component 7 (C7) deficiency in a highly inbred Arab population in Israel.
• To investigate the genetic mutation responsible for C7 deficiency in this cohort.

Main Methods:

• Biochemical and molecular analyses were conducted on samples from individuals affected by Neisserial infections and their families.
• Pedigree analysis was used to trace the inheritance pattern of C7 deficiency.

Main Results:

• The study identified C7 deficiency in the index case with recurrent infections and a sibling.
• The identified mutation (G1135C) is consistent with a previously described mutation prevalent in Israeli Jews of Moroccan ancestry.
• The findings highlight the protective role of complement deficiency in certain Neisserial infection contexts.

Conclusions:

• This study establishes the presence of C7 deficiency in an Arab population in Israel, linked to a known mutation.
• The findings underscore the importance of genetic background in complement deficiency and its clinical manifestations.
• Complement deficiency can confer protection against specific infections, influencing disease outcomes.