Ai. Berkel et al., Molecular, genetic and epidemiologic studies on selective complete C1q deficiency in Turkey, IMMUNOBIOL, 201(3-4), 2000, pp. 347-355
Selective complete C1q deficiencies (SCDC1q) of the complement component C1
q are rare genetic disorders with high prevalence of lupus-erythematosus-li
ke symptoms and recurrent infections. Among the 41 published cases from 23
families, 10 derive from 6 Turkish families. One particular mutation leadin
g to a stop codon in the C1q A gene was first identified in members of a Gy
psy family from the Slovac Republic. Later the same mutation has been found
in all cases in four SCDC1q families from Turkey suggesting that one parti
cular defective allele may be present in the populations of Southeastern Eu
rope and Turkey.
This study was undertaken to investigate the frequency of C-->T mutation in
exon II of C1qA gene in Turkish population by using allele-specific polyme
rase chain reaction (PCR) and PCR-restriction fragment length polymorphism
(PCR-RFLP). Among the 1544 patients from 15 pediatric departments and an ad
ditional 89 SLE patients of various ages no C1qA gene mutation was found. T
here were 43 heterozygous and 4 homozygous mutations in 161 family members
or relatives investigated from the 4 families known with SCDC1q. Among the
223 inhabitants who were nonrelative to the 3 SCDC1q families living in the
same village were screened for mutation and one heterozygous individual wa
s observed.
Although this mutant allele appears to be at a low prevalence in the popula
tion rested, individuals with recurrent infections or symptoms of lupus ery
thematosus-like syndrome should be tested for this mutation to rule out thi
s type of C1q deficiency.