RESUMO
HLA-A and B antigens were determined in a study of 37 couples and their children with trisomy 21 Down syndrome (DS), using a standard microlymphocytotoxicity test. The comparison groups included 76 couples and their healthy children. All individuals were Caucasians from the same geographical area, and there was no history of consanguinity. The parents of children with DS did not show an association with a specific HLA antigen or haplotype. Sixteen of the 37 couples (43.24%) having children with DS share two or more antigens at the A and/or B locus. This was significantly higher than the proportion in the control group (6/76, or 7.88%). Of the 16 couples having children with DS and sharing two or more antigens, eight had a haplotype in common, in contrast with only two couples in the control group. The data suggest that sharing of parental HLA-A and B antigens may be related either to the occurrence of trisomy 21 zygotes or to prenatal survival of affected embryos and fetuses.
Assuntos
Síndrome de Down/genética , Frequência do Gene , Variação Genética , Antígenos HLA/genética , Adulto , Criança , Síndrome de Down/imunologia , Feminino , Genótipo , Antígenos HLA-A , Antígenos HLA-B , Humanos , Masculino , PaisRESUMO
Lymphocytes from an extended family of Welsh ponies were tested in a microcytotoxicity test against Thoroughbred and Arabian horse-derived antisera, which defined 4 and 6 equine lymphocyte antigen (ELA) specificities, respectively. Mixed leukocyte culture (MLC) tests were also performed. Welsh pony lymphocytes reacted to the Thoroughbred antisera. Most of the ponies' lymphocytes showed reactivity to 2 of the Thoroughbred ELA specificities, the offspring inheriting 1 antigen from each parent. Antigenic determinants were only partially demonstrated with Arabian antisera, although results indicated serologic identities among the ponies, which may reflect the historical background of the Welsh pony. There was no MLC reactivity between cells from most pairs of ponies that were ELA-identical, as typed with the Thoroughbred antisera, but cells from 2 ELA-identical pairs did react in MLC, indicating that MLC and ELA determinants may be on separate loci, as in other species.