A case report of complement C4B deficiency in a patient with steroid and IVIG-refractory anti-NMDA receptor encephalitis

Table 1 Complement genetic profiles of the patient and his family members

	Plasma C4 (mg/dL)	Plasma C3 (mg/dL)	RCCX-C4 haplotypes	Total C4 GCN	C4 Long GCN	C4 Short GCN	C4A GCN	C4B GCN*	C4A Protein	C4B Protein	C4 protein Haplotype1	C4 protein Haplotype2
Patient	7.7	118.5	LL / L	3	3	0	2	(1)	A3A3	Q₀	A3Q₀	A3
Mother	20.2	106.4	LL / LLS	5	4	1	3	2 (1)	A3A3A3	B2, Q₀	A3Q₀	A3A3B2
Father	19.2	167.6	L / L	2	2	0	2	0	A3A3		A3	A3
Maternal Step Brother	10.0	91.1	LL / L	3	3	0	1	2 (1)	A3	B1, Q₀	A3Q₀	B1

GCN gene copy number, L C4 long gene, S C4 short gene, LL long-long, LS long-short, LLS long-long-shortm, A3 C4A allotype 3
B1 C4B allotype 1, B2 C4B allotype 2, Q₀ zero quantity of C4 protein from the corresponding gene;
* C4B GCN in brackets indicates the number of mutant gene

ISSN: 1471-2377