Nomenclature for human complement component C2

Journal oflmmunological Methods, 163 (1993) 1-2

1

© 1993 Elsevier Science Publishers B.V. All rights reserved 0022-1759/93/$06.00

JIM 06759

Immunological standardization

Nomenclature for human complement component C2 WHO-IUIS Nomenclature Sub-Committee ** This n o t e describes the d e s i g n a t i o n s for v a r i a n t s of the h u m a n c o m p l e m e n t c o m p o n e n t C2, which w e r e a p p r o v e d by the N o m e n c l a t u r e C o m m i t t e e of the I n t e r n a t i o n a l U n i o n of I m m u n o l o g i c a l Societies (IUIS).

m

m

mira

,,,m,m ~1-

C

.4-

C

m

m m

A08

A04 AX

A03

m

A02

C

803

AT

C

B

B07

BOB

B1

BH

6,)

Fig. 1. Schematic representation of the C2 allotypes of C2 (IEF and immunoblotting of the native protein) and nomenclature of C2 variants. The two major bands of the common form C2 C are indicated by arrows. The distance between the arrows is used as a reference unit for the estimation of the relative IEF migration distances, permitting a numeric designation. The new variant designation is indicated in bold characters.

* This article was drafted by a group of experts at the time of the VI Complement Genetics Workshop (Mainz, Germany, 1989) and has been approved by the Nomenclature Committee of IUIS. Requests for reprints and all correspondence should be addressed to the Chairman of the IUIS Nomenclature Committee, Dr. M.D. Kazatchkine, Unit6 d'Immunopathologie, H6pital Broussais, 96 rue Didot, 75014 Paris, France. First published in Bull. WHO 70 (1992) 527-528. * * Members of the group of experts: G. Hauptmann (France) (Chairman), M. Abbal (France), C.A. Alper (USA), D. Arnold (France), F. Christiansen (Australia), R.L. Dawkins (Australia), G. Doxiadis (Germany), G. Geserick (Germany), C.M. Giles (UK), M. Hobart (UK), I. Jahn (France), M.L. Lokki (Finland), G. Mauff (Germany), S. Nakamura (Japan), G.J. O'Neill (USA), C. Rittner (Germany), P.M. Schneider (Germany), O.G. Segurado (Spain), I. Siemens (Germany), K. Suzuki (Japan), K. Tokunaga (Japan), and B. Uring-Lambert (France).

C2 variants T h e r e f e r e n c e typing r e c o m m e n d e d by the VI Complement Genetics Workshop permits nine e l e c t r o p h o r e t i c v a r i a n t s of C2 to b e d i s t i n g u i s h e d (Fig. 1). I n a d d i t i o n to the c o m m o n form C2 C, four acidic v a r i a n t s a n d four basic v a r i a n t s are observed ( T a b l e I). D i f f e r e n c e s in p I b e t w e e n v a r i a n t s are difficult to establish. W e t h e r e f o r e p r o p o s e to design a t e the v a r i a n t s according to t h e i r relative I E F (isoelectric focusing) m i g r a t i o n , taking the dist a n c e b e t w e e n the two m a j o r b a n d s of the comm o n C2 C as a r e f e r e n c e unit. This distance has b e e n e s t i m a t e d to b e a p p r o x i m a t e l y 0.1 p H inter-

2 TABLE I T H E C O N C L U S I V E I D E N T I F I C A T I O N O F C2 A L L O T Y P E S a New designation Old designation

A08 -

Native C2 C2a fragment Desialized C2

+ . +

Native C2 and desialized C2

+

A04 AX

A03 -

+ .

+ .

.

+

.

A02 AT

C C

B03 B

B07 -

B08 BH

B1 BJ

+

+

+ +

+ + +

+ + _+

+

+

+

+

+

+

.

.

.

+

.

.

+

a + : m e t h o d sufficient by itself for the identification of the variant. + : results need confirmation by data obtained from other methods. - : m e t h o d not sufficient by itself for identifying the variant. Study of native and desialized C2 is necessary to identify all C2 variants.

val (Meo et al., 1976). As initially proposed, the common C2 allele is called C2" C; the acidic and basic alleles are designated C2*A and C2*B, respectively (Alper, 1976; Jahn et al., 1990). The numeric symbols, corresponding to the relative migration value, clearly permit the rare acidic and rare basic variants to be differentiated. However, the most common basic variant (approximate gene frequency, 0.02-0.04), designated in this nomenclature as B03, may still in common usage be named C2 B. The nomenclature of all the variants tested for the Workshop is given in Fig. 1 and conforms to the guidelines of the international system for human gene nomenclature (Shows et al., 1979). The previously described C2 A1 and C2 A2 variants (Pariser et al., 1978; Raum et al., 1979) were not available for comparison. Consequently, the present note probably does not include all of the variants of C2 thus disclosed. Other variants and new vari-

ants may easily be included in this nomenclature after comparison with the currently reported variants.

References Alper, C. (1976) Inherited structural polymorphism in h u m a n C2: evidence for genetic linkage between C2 and BF. J. Exp. Med. 144, 1111-1115. Jahn, I. et al. (1990) C2 reference typing report. Complement Inflamm. 7, 175-182. Meo, T. et al. (1976) Mapping of the H L A locus controlling C2 structural variants and linkage disequilibrium between alleles C22 and Bw 15. Eur. J. Immunol. 6, 916-919. Pariser, K. et al. (1978) Evidence for silent or null gene in hereditary C2 deficiency. J. Immunol. 121, 2580-2581. R a u m , D. et al. (1979) Mapping of the structural gene for the second c o m p o n e n t of complement with respect to the h u m a n major histocompatibility complex. A m . J. Hum. Genet. 31, 35-41. Shows, T.B. et al. (1979) International system for h u m a n gene nomenclature. Cytogenet. Cell Genet. 25, 96-116.