Author/Editor		Kotnik, Vladimir; Lužnik-Bufon, Tatjana; Schneider, Peter M; Kirschfink, Michael
Title		Molecular, genetic, and functional analysis of homozygous C8 beta-chain deficiency in two siblings
Type		članek
Source		Immunopharmacology
Vol. and No.		Letnik 38
Publication year		1997
Volume		str. 215-21
Language		eng
Abstract		C8 deficiency is associated with an increased susceptibility to neisserial infections. We present a case of an 11 year old botywho suffered from infection with Neisseria meningitidis. Medical history of the patient and his family (n = 5) did not indicate any previous immunodeficiency symptoms. Results from the analysis of phagocyte and lymphocyte functions were within the normal range. No hemolytic activities of the classical (CH50) and the alternative (AOH50) pathways of complement were measurable, and SC5b-9 protein complexes could not be detected in the patient's plasma. Further analysis by higly sensitive ELISA and functional assays revealed a complete deficiency of C8. Upon the reconstitution with purified C8 totalhemolytic activity could be restored. SDS-PAGE and Western blot analysis established a deficiency of the C8 beta chain. Genetic analysis at thegenomic DNA leveldemonstrated the common C-T mutation in exon 9 of the C8B gene. Family analysis presented the older sister with non-detectable function of C8 in serum, both parents with about half-normal C8 titres, and the younger sister with normal C8 function. The parens and both sisters were asymptomatic, although the older of the sisters presented with the same complete C8 beta-chain deficiency as the patient described. In conclusion: the common C-T mutation in the C8B is the genetic basis of C8 beta-chain deficiency in two members of this Bosnain family.
Descriptors		COMPLEMENT 8 COMPLEMENT MEMBRANE ATTACK COMPLEX COMPLEMENT HEMOLYTIC ACTIVITY ASSAY CHILD ALLELES DNA EXONS HOMOZYGOTE MENINGITIS, MENINGOCOCCAL PHAGOCYTES T-LYMPHOCYTES