Deficiency of the seventh component of complement in a Taiwanese boy.
Inherited complement deficiencies are rare, particularly those associated with late components of the complement cascade. We report a 5-year-4-month-old Taiwanese boy with systemic meningococcal infection who had undetectable CH50 level of < 6 U/mL (normal, 32.6-39.8 U/mL). Levels of C3, C4, C5, C6 and C8 were normal, but C7 was undetectable (< 5.8 mg/dL; reference, 55-85 mg/dL). The patient's sister was also C7-deficient (CH50 < 6 U/mL, C7 < 5.8 mg/dL). His father's CH50 was 25.9 U/mL and C7 was 27.8 mg/dL. His mother's CH50 was 31.2 U/mL and C7 was 22.7 mg/dL. His parents thus both had a partial complement deficiency, indicating an autosomal codominant inheritance pattern. Awareness of the possibility of late complement deficiency is important as they comprise a small percentage of patients who present with disseminated meningococcal disease or other serious infections caused by encapsulated organisms.
Chiang
Yi-Chi
YC
Department of Pediatrics, Mackay Memorial Hospital, and Department of Pediatrics, Ho-Ping Branch, Taipei City Hospital, Taipei, Taiwan.
Shyur
Shyh-Dar
SD
Huang
Li-Hsin
LH
Wen
Ta-Chzng
TC
Lin
Mao-Tsair
MT
Yang
Hwai-Chih
HC
Liang
Pei-Hsuan
PH
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D044466:Asian People; D002675:Child, Preschool; D002895:Chromosomes, Human, Pair 5; D003184:Complement C7 / Q000172:deficiency* / Q000235:genetics*; D006801:Humans; D008297:Male; D008585:Meningitis, Meningococcal / Q000175:diagnosis*; D009345:Neisseria meningitidis / Q000302:isolation & purification*; D010375:Pedigree; D013624:Taiwan
D000900:Anti-Bacterial Agents; D003184:Complement C7