title: Increased frequency of the null allele at the complement C4b locus in autism.
abstract: Associations between C4 deficiency and autoimmune disorders have been found over the past several years. Since autism has several autoimmune features, the frequencies of null (no protein produced) alleles at the C4A and C4B loci were studied in 19 subjects with autism and their family members. The autistic subjects and their mothers had significantly increased phenotypic frequencies of the C4B null allele (58% in both the autistic subjects and mothers, compared with 27% in control subjects). The siblings of the autistic subjects also had an increased frequency of the C4B null allele, but this increase was not significant. The fathers had normal frequencies of this null allele. All family members had normal frequencies of the C4A null allele, all normal C4A and C4B alleles and all BF and C2 alleles.
authors.affiliation: Department of Biology, Utah State University, Logan 84322-6800.
authors.forename: R P
authors.initials: RP
authors.lastname: Warren
authors.forename: V K
authors.initials: VK
authors.lastname: Singh
authors.forename: P
authors.initials: P
authors.lastname: Cole
authors.forename: J D
authors.initials: JD
authors.lastname: Odell
authors.forename: C B
authors.initials: CB
authors.lastname: Pingree
authors.forename: W L
authors.initials: WL
authors.lastname: Warren
authors.forename: E
authors.initials: E
authors.lastname: White
mesh_terms: D000483:Alleles; D001321:Autistic Disorder / Q000235:genetics* / Q000276:immunology*; D002648:Child; D015934:Complement C4a / Q000235:genetics; D015935:Complement C4b / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D008297:Male
chemical_list: D015934:Complement C4a; D015935:Complement C4b