title: The identification of a novel splicing mutation in C1qB in a Japanese family with C1q deficiency: a case report.
abstract: C1q deficiency is a rare disease that is associated with a high probability of developing systemic lupus erythematosus. We report a 4-year-old Japanese girl who presented with fever, facial erythema, joint pain, and oral ulceration. Complement deficiencies were suspected because of her persistent hypocomplementemia and normal levels of the complement proteins C3 and C4. We identified a novel homozygous splicing mutation in the C1qB gene, c.187 + 1G > T, which is the first mutation to be confirmed in a Japanese individual. Because treatment with steroids and immunosuppressive drugs was not effective, we commenced use of fresh frozen plasma to provide C1q supplements. Currently, the patient remains almost asymptomatic, and we are attempting to control the drug dosage and administration intervals of fresh frozen plasma.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Higuchi
authors.affiliation: Department of Pediatrics, National Hospital Organization Okayama Medical Center, 1711-1 Tamasu, Kita-ku, Okayama 701-1192, Japan. junshimi@okayama3.hosp.go.jp.
authors.forename: Junya
authors.initials: J
authors.lastname: Shimizu
authors.forename: Michiyo
authors.initials: M
authors.lastname: Hatanaka
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kitano
authors.forename: Hajime
authors.initials: H
authors.lastname: Kitamura
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takada
authors.forename: Masataka
authors.initials: M
authors.lastname: Ishimura
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hara
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohara
authors.forename: Kenji
authors.initials: K
authors.lastname: Asagoe
authors.forename: Toshihide
authors.initials: T
authors.lastname: Kubo