MULTIPLE IDENTIFICATION OF A PARTICULAR TYPE OF HEREDITARY C1Q DEFICIENCY IN THE TURKISH POPULATION - REVIEW OF THE CASES AND ADDITIONAL GENETIC AND FUNCTIONAL-ANALYSIS
F. Petry et al., MULTIPLE IDENTIFICATION OF A PARTICULAR TYPE OF HEREDITARY C1Q DEFICIENCY IN THE TURKISH POPULATION - REVIEW OF THE CASES AND ADDITIONAL GENETIC AND FUNCTIONAL-ANALYSIS, Human genetics, 100(1), 1997, pp. 51-56
Complete selective deficiencies of the complement component C1q are ra
re genetic disorders that are associated with recurrent infections and
a high prevalence of lupus erythematosus-like symptoms. All C1q defic
iencies studied at the genetic level revealed single-base mutations le
ading to termination codons, frameshifts or amino acid exchanges and t
hese were thought to be responsible for the defects as no other aberra
tions were found. One particular mutation, leading to a stop codon in
the C1qA gene, was first identified in members of a Gypsy family from
the Slovak Republic. The same mutation has been found in all cases of
C1q deficiency from Turkey that have been investigated. Here we presen
t the results of genetic analysis of the C1q genes from three families
and give information on further C1q-deficient members of two families
that have not been reported elsewhere. Reviewing all cases of C1q def
iciency from Turkey prompted us to hypothesize that one particular def
ective allele is present in the population of southeast Europe and Tur
key. With a novel polymerase chain reaction-restriction fragment lengt
h polymorphism (PCR-RFLP) analysis and allele-specific PCR we are able
to detect even asymptomatic, heterozygous carriers of the mutation, w
hich will enable genetic counseling of the affected individuals.